CONTENTS
ACKNOWLEDGMENTS ............................................... ........................................................................ ................................................... .......................... 3 ABSTRACT ................................................. ........................................................................... .................................................... .......................................... ................ 3 1
INTRODUCTION ................................................... ............................................................................ ................................................... .......................... 4
2
BUILDING INFORMATION MODELING.................................................. ................................................................... ................. 5
3
2.1
Definition ................................................ .......................................................................... .................................................... .................................. ........ 5
2.2
Applications ................................................ .......................................................................... .................................................... .............................. .... 6
2.3
Key benefits of BIM ..................................... .............................................................. .................................................. .............................. ..... 7
2.4
Challenges of BIM .......................... .................................................... ................................................... .......................................... ................. 8
2.5
Tools available for BIM................................................. .......................................................................... ...................................... ............ 9
2.6
4D Building Information Modeling (4D BIM) ............................. ..................................................... ........................ 11
2.7
Autodesk and Building Information Modeling ................................................. ................................................... .. 13
2.7.1
Autodesk Revit ..................................... .............................................................. .................................................. ............................ ... 13
2.7.2
Autodesk Navisworks ............................... ........................................................ ................................................. ........................ 14
MODELING NEW DEVELOPMENT IN URBAN AREAS ........................................ ........................................ 16 3.1
Geographical Information System – GIS .................................. .......................................................... ........................ 16
3.2
City GML ................................................ .......................................................................... .................................................... ................................ ...... 18
3.2.1 3.3
4
5
Montreal CityGML ............................ ...................................................... .................................................... ................................ ...... 21
Urbanization in Downtown Montreal .................................................. ................................................................. ............... 25
3.3.1
Landscape change ................................................ .......................................................................... .................................... .......... 25
3.3.2
Traffic impact ........................................................ .................................................................................. ..................................... ........... 28
.................................................................................... .............. 30 Case of study “Roccabella”. ...................................................................... 4.1
General information.................................................. ........................................................................... ........................................ ............... 30
4.2
Developing Roccabella Ro ccabella model m odel in Autodesk Revit ............................................. ............................................. 31
4.3
Developing 4D 4 D model m odel of Roccabella. ........................................... ............................................................... .................... 37
CONCLUSIONS .................................................... ............................................................................. ................................................. ........................ 39
REFERENCES ................................................ .......................................................................... .................................................... .................................... .......... 39
1
LIST OF TABLES
Table 1 BIM Authoring Tools (Reinhardt, 2009) ........................................ ............................................................ .................... 10 Table 2 BIM Tools for Shop drawing and a nd Fabrication (Reinhardt, 2009) ....................... 11 Table 3 BIM Construction Management and Scheduling Tools T ools (Reinhardt, 2009) ........ 11 Table 4 Autodesk Navisworks types (Autodesk Inc., Inc ., 2014) ........................................... ........................................... 15 Table 5 Main Characteristics Buildings Area of Study (Info provided by projects sales offices and its websites) ................................................... ............................................................................ ............................................. .................... 26 Table 6 Building Parking spaces Vs. Parking lots spaces ............................................. ............................................. 29
LIST OF FIGURES
Figure 1 Social BIM (Sanveo, 2014)........................ 2014 ).................................................. .................................................... .............................. .... 6 Figure 2 BIM applications ap plications (Eastman C., 2011) ................................................... ................................................................ ............. 7 Figure 3 4D model using Autodesk Navisworks Na visworks Manage (Mrasbuilt, 2014) .................. 12 Figure 4 Revit Views (Inside-the-factory, 2014) ............................................................ ............................................................ 14 Figure 5 Layering GIS (Burnaby, 2014)................................................. ......................................................................... ........................ 17 Figure 6 Modularization of CityGML 1.0.0. (Kolbe T., 2008) ......................................... ......................................... 19 Figure 7 CityGML Levels of detail (Kolbe T., 2008) ................................................ ....................................................... ....... 20 Figure 8 Geometrical Level Le vel of Detail CityGML (Löwnera M. O., 2013) ......................... ......................... 21 Figure 9 Montreal 3D Model (Montreal City - Geomatics Division, 2014) ...................... 22 Figure 10 Representation of construction projects downtown Montreal – CityGML (Montreal City - Geomatics Division, 2014) 2014 ) ............................................... ................................................................... .................... 23 Figure 11 Montreal downtown Montreal downtown cityGML using Global Mapper ....... 24 Figure 12 Montreal downtown cityGML using Snowflake GML viewer .......................... .......................... 24 Figure 13 Downtown Montreal Area of study (Google Maps, 2014) 201 4) .............................. .............................. 25 Figure 14 Comparison study area 2010 (a.) and 2013 (b.) (Google Earth, 2010 - 2013) .................................................. ............................................................................ .................................................... ................................................... ................................ ....... 27 Figure 15 1 5 Project Pro ject Location (Google Maps 2014) ................................................ ........................................................... ........... 30 Figure 16 Roccabella typical floor: Walls drawn on top of the CAD file and first assumptions made. ....................................................................... ................................................................................................. ................................ ...... 33 Figure 17 Example of differences between unit C1 on the website and the design drawings .................................................. ........................................................................... .................................................. ............................................. .................... 34 Figure 18 Adding details d etails to the model mo del ................................................... ........................................................................... ........................ 35 Figure 19 Cross section of the Roccabella model mod el 3 to 32 levels. ........................... .................................. ....... 36 Figure 20 Complete Tower. Differences Differ ences between the levels. ........................................ ........................................ 37 Figure 21 4D process in Navisworks Manage 2014 ................................................ ...................................................... ...... 38
2
LIST OF TABLES
Table 1 BIM Authoring Tools (Reinhardt, 2009) ........................................ ............................................................ .................... 10 Table 2 BIM Tools for Shop drawing and a nd Fabrication (Reinhardt, 2009) ....................... 11 Table 3 BIM Construction Management and Scheduling Tools T ools (Reinhardt, 2009) ........ 11 Table 4 Autodesk Navisworks types (Autodesk Inc., Inc ., 2014) ........................................... ........................................... 15 Table 5 Main Characteristics Buildings Area of Study (Info provided by projects sales offices and its websites) ................................................... ............................................................................ ............................................. .................... 26 Table 6 Building Parking spaces Vs. Parking lots spaces ............................................. ............................................. 29
LIST OF FIGURES
Figure 1 Social BIM (Sanveo, 2014)........................ 2014 ).................................................. .................................................... .............................. .... 6 Figure 2 BIM applications ap plications (Eastman C., 2011) ................................................... ................................................................ ............. 7 Figure 3 4D model using Autodesk Navisworks Na visworks Manage (Mrasbuilt, 2014) .................. 12 Figure 4 Revit Views (Inside-the-factory, 2014) ............................................................ ............................................................ 14 Figure 5 Layering GIS (Burnaby, 2014)................................................. ......................................................................... ........................ 17 Figure 6 Modularization of CityGML 1.0.0. (Kolbe T., 2008) ......................................... ......................................... 19 Figure 7 CityGML Levels of detail (Kolbe T., 2008) ................................................ ....................................................... ....... 20 Figure 8 Geometrical Level Le vel of Detail CityGML (Löwnera M. O., 2013) ......................... ......................... 21 Figure 9 Montreal 3D Model (Montreal City - Geomatics Division, 2014) ...................... 22 Figure 10 Representation of construction projects downtown Montreal – CityGML (Montreal City - Geomatics Division, 2014) 2014 ) ............................................... ................................................................... .................... 23 Figure 11 Montreal downtown Montreal downtown cityGML using Global Mapper ....... 24 Figure 12 Montreal downtown cityGML using Snowflake GML viewer .......................... .......................... 24 Figure 13 Downtown Montreal Area of study (Google Maps, 2014) 201 4) .............................. .............................. 25 Figure 14 Comparison study area 2010 (a.) and 2013 (b.) (Google Earth, 2010 - 2013) .................................................. ............................................................................ .................................................... ................................................... ................................ ....... 27 Figure 15 1 5 Project Pro ject Location (Google Maps 2014) ................................................ ........................................................... ........... 30 Figure 16 Roccabella typical floor: Walls drawn on top of the CAD file and first assumptions made. ....................................................................... ................................................................................................. ................................ ...... 33 Figure 17 Example of differences between unit C1 on the website and the design drawings .................................................. ........................................................................... .................................................. ............................................. .................... 34 Figure 18 Adding details d etails to the model mo del ................................................... ........................................................................... ........................ 35 Figure 19 Cross section of the Roccabella model mod el 3 to 32 levels. ........................... .................................. ....... 36 Figure 20 Complete Tower. Differences Differ ences between the levels. ........................................ ........................................ 37 Figure 21 4D process in Navisworks Manage 2014 ................................................ ...................................................... ...... 38
2
ACKNOWLEDGMENTS
I take this opportunity to express my profound gratitude and deep regards to Dr. Amin Hammad for his exemplary guidance, monitoring and constant encouragement throughout the course of this project. I also extend my gratitude to my colleagues Xue Bai and Camila Omori without whom the development of the model would not be possible and also for helping me and allowing me to be part of a great working team. I would also like to thank all my officemates Mohammad Soltani, Mohamad Langari Hassaan Siddiqui and Khaled El Ammari for their advice and guidance. I am obliged to staff members of Magil Construction, for the valuable information provided by them in their respective fields. I am grateful for their cooperation during this period.
ABSTRACT
Nowadays there is a growing interest in the implementation of Building Information Modeling (BIM) in order to improve the construction processes since the first stages of the project and during its life cycle. The first part of this report includes an overview of BIM it includes the definition, applications, benefits, challenges, tools available and finally 4D BIM. In order to really understand this concepts, a 4D model of the Roccabella building that is actually under construction in downtown Montreal was developed (case of study). During the process of gathering information for the development of the 4D model, we realized the large number of buildings that are under construction in downtown Montreal. This prompted us to expand the concept to urban planning that in turn led us to CityGML and GIS. The second part of this report includes the definition and applications of the GIS and CityGML. Also a description of the Montreal CityGML model and the issues that we faced with the available data. Finally a description of the new buildings in the study area selected its main characteristics and some of the impacts that they can cause in the downtown was included.
3
1
INTRODUCTION
Architecture, engineering and construction areas have experienced in the th e last decade a significant increase in productivity at the same time that they have improved the sustainability of the construction process. Where is the key to such a major change? After analyzing the major causes of delay and cost co st overrun in projects we can conclude that most of the delays were consequence of incidents caused within workflows that produced delays and misunderstandings between project managers, contractors and suppliers. Any changes made to the project needed at least a week to be communicated to the other agents involved. In construction projects the technical information that is handled is usually represented by two dimensional CAD drawings. Although it is possible to make accurate measurements, the information contained in the those files are not updated or linked to the construction process (foundation, drainage, masonry, installation, painting, etc.) and the agents involved (architect, engineer, manufacturer, lender, contractor, etc.). If materials are budgeted from the design phase, models are developed in 3D, and the project is planned, all information were integrated and linked, project management is simplified, not only during construction, but also to over the life cycle of the building. In response to this need was born the Building Information Modeling (BIM). Now, despite all its advantages, the BIM only focuses on the building environment. In order to extend it to other applications like urban planning in larger areas (city or metropolitan area) or a group of buildings other international standards like as CityGML and GIS can be used. The following chapters present a description of the BIM, GIS and CityGML. A case of study is also included.
4
2
2.1
BUILDING INFORMATION MODELING
Definition
Building information modeling (BIM) is a revolutionary technology and process that has transformed the way buildings are designed, analyzed, constructed, and managed. BIM is basically three dimensional representation of a building and its inherent characteristics generated with the use of specialized software. It can be considered as a platform to share knowledge and communicate between project participants. The model contains the information related to the structure, which includes physical/functional characteristics and project life cycle information, in what is called series of “smart objects”. For example, inside a building the heating system will contain the information
about the suppliers, technical information (like temperature limits, flow rates, etc.), how it should be operated and how it should be maintained (S. Azhar, 2011).
BIM can be used in a basic level, just to share the concept of the facility in 3D, but further information will not be included, which means that it is not use in its full extent. Generally it is use by contractors in order to obtain jobs. Another case is when just one of the participants in the project creates a BIM model for its use but it does not share it with the other participants. For example, a designer company is hired to design a new building and they use BIM due to the advantages offered by the method but the final product will be submitted in 2D, so the developer and the constructor will not have access to the model (Vardaro, 2009). Another approach will be a “social” BIM (see Figure 1), which will be developed and
shared by all the participants in the project. For example the design engineers/architects will create the basic model and it will be improved with the help of the construction manager and the contractors. All the systems of the building can be added by the responsible designer (structural system, hydraulic system, etc.). Later it can be modified to show the “as built” work (Hergunsel, 2011).
5
Figure 1 Social BIM (Sanveo, 2014)
Using this approach will facilitates the integrated project delivery and also it provides an opportunity for design team members to break out of individual silos and work together in a collaborative way.
2.2
Applications
Building Information Modeling has several applications, the most representatives ones are (S. Azhar, 2011): -
3 dimensional visualization of the project
-
Easier way to generate drawings
-
Easier way to review designs and perform the required changes
-
Cost estimating
Safety planning, by reviewing higher risk tasks in the model before performing them -
Avoid conflicts between the systems in the building 6
The Figure 2 illustrates the general applications of BIM and its relationship.
Figure 2 BIM applications (Eastman C., 2011)
2.3
Key benefits of BIM
BIM offers a three dimensional representation of the facility under study. For the first stage of the project, the bidding phase, it will help to get a better understanding and analysis of the proposal. Further benefits will be seen when the decisions about aesthetics and spaces are required. The model, especially if developed by coordinated efforts of the designers and contractors before the construction process, will help to reduce in great amount the number of errors that are usually incurred during design phase (Hergunsel, 2011).
7
Considering the large number of software available on the market, BIM also implements Industry foundation classes (IFC) compatibility. IFC is a file format specification. It is an object-based file format with a data model developed by building SMART. It aims to facilitate interoperability in the architecture, engineering and construction (AEC) industry (BuildingSMART International home of open BIM, 2014). One of the major advantages of the BIM is that it facilitates obtaining faster and more effective processes. This will be achieved due that sharing and adding or modifying information this way is easier and it can be reused (S. Azhar, 2011). In order to reduce constructions costs and times some elements could be prefabricated and / or welded (especially when dealing with complex elements) before they are required. Developing a BIM model compatible with the software used by the fabricator, will ensure the accuracy required for the task (Hergunsel, 2011). The Model can be used to estimate the costs of the project. The more accurate and complete the inputs the more accurate the outcome (for example if it is developed including hydraulic and electric design). It can be used in the first stage for example for bidding purposes, and later for more accurate cost estimation and during the construction for expenses control. BIM also enables great reduction of waste and environmental control. By having more exact quantity take-offs we are ensuring that materials will not be over-ordered it will also enables more efficient materials handling and waste recovery. A 3D model can be also use to review complex procedures minimizing construction risks.
Summarizing, all the benefits mentioned will be reflected into better productivity and quality, accuracy in cost estimating, time saving, safety and better operation due that it can be used during the whole life cycle of the facility.
2.4
Challenges of BIM
The development of the initial framework of a Building Information Model will require more effort than the traditional methods. The design requires extra works considering that must of the professionals are not use to think in 3 dimensions. The 8
initial pre visualization is more demanding than the 2D methods (Precise Drafting Inc, 2014).
2.5
One of the biggest advantages of a BIM is the easier way to perform changes above the whole design. That can also be translated into a disadvantage because the client may keep requiring changes that could generate great impact in construction and design costs (Precise Drafting Inc, 2014). This system, a difference with the traditional, requires that the equipment used which includes hardware and software, perform in a higher level and the generated files will be much greater in size as well (Precise Drafting Inc, 2014). The design requires extra efforts considering that must of the professionals are not use to think in 3 dimensions. The initial pre visualization is more demanding than the 2D methods (Precise Drafting Inc, 2014). Another big challenge is the shared information. A complete BIM will include relevant information for example about suppliers, cost, times, etc. It can generate copyright issues. Also in this case the party sharing this data may be in risk of giving much to other that later on can use it to compete for jobs. Now, this also can create another issue that the initial developer of the model may not want to share it with for example owners and constructors, and if it does it, the problem would be how the costs of its development and operation must be divided (S. Azhar, 2011).
Tools available for BIM.
After mentioning all the benefits that BIM can offer for the design, construction and lifecycle of a facility, now it is important to mention the tools that are available for its implementation. BIM tool is all software application that manipulates the model in order to obtain a specific outcome. The software must be able to not just allow the development of the 3D model, also it must be able to add, modify, delete and reuse information (Fernandes, 2013). Table 1 shows the BIM authoring tools and their primary functions.
9
Table 1 BIM Authoring Tools (Reinhardt, 2009)
Table 2 presents BIM tools for structural, mechanical, electrical and plumbing contractors and for drawing and fabrication. 10
Table 2 BIM Tools for Shop drawing and Fabrication (Reinhardt, 2009)
Other complementing tools are available for construction management and scheduling as shown in Table 3 BIM Construction Management and Scheduling Tools Table 3 below.
Table 3 BIM Construction Management and Scheduling Tools (Reinhardt, 2009)
From all the above mentioned the one that is of interest to this report is Autodesk Navisworks Manage due that it includes a feature called Timeliner to simulate construction schedules. This subject will be addressed more detailed in further chapters.
2.6
4D Building Information Modeling (4D BIM)
4D BIM is the term used to describe the link between the three dimensional model (physical aspect) with time or schedule of the work. This will allow the visualization of the construction sequence in the same order that it is planned (McKinney, 1996).
11
This is a powerful tool, because it will help, not just with the time control, it will also help to prevent and solve problems before the construction. A good example would be the avoidance of work conflicts, that will improve the time and organization of the work making the process more efficient (Dixit, 2007). Nowadays, as shown in Table 3 above, we can find several tools to develop a 4 dimensional model by linking the 3D model with the schedule of the work.
Figure 3 4D model using Autodesk Navisworks Manage (Mrasbuilt, 2014)
Figure 3 shows and example of a 4D model created with Autodesk Navisworks and Revit. It is important to clarify that tower-crane added in the Figure 3 is just decorative; the software is not able to animate construction equipment. The 3D model, is developed in Revit, the schedule can be developed in specialized softwares like Microsoft Project, Primavera or Excel (anyone compatible with the program in use to develop the 4D) then both, 3D model and schedule are imported to Navisworks were they are linked together and the simulation of the work can be seen. 12
2.7
Autodesk and Building Information Modeling
Autodesk is a multinational company that develops software for architecture, engineering, construction, manufacturing, media, and entertainment (Autodesk Inc., 2014). The company is worldwide known specially for AutoCAD, but also, Revit both are mainly used by architects, engineers, and designers in general.
2.7.1 Autodesk Revit
Revit is a BIM software developed by Autodesk, as mentioned before, used nowadays by architects, engineers, designers and contractors. The definition given by Autodesk is: “The Revit platform for building information
modeling is a design and documentation system that supports the design, drawings, and schedules required for a building project”.
Initially Revit was developed by Parametric Technology Corporation in 1997. The main purpose at that time was just architectural design. Later, in 2002 Autodesk in an effort to keep providing solutions to all the requirements of the industry purchased Revit for $133 million (Autodesk Inc., 2014). Now, according to the study “Autodesk Revit: Implementation in Practice” the major
strengths of the software are:
The compatibility with AutoCad facilitates 2D and 3D interoperability for hybrid workflows It facilitates the design changes and it automatically upgrades data and the schedule of the work. The coordination of the design tasks can be performed in an easier way.
It provides quick feedback for design decisions
Fast and convenient generation of design presentations for client approvals
Due to the 3D views it facilitates the design presentations for approvals, also improves de understanding and communication with clients and builders
13
Figure 4 Revit Views (Inside-the-factory, 2014)
Figure 4 shows the views offered by Revit. You can generate the floor plans, the elevation, and general 3D view. It is also shown (top left) some of the options available for the walls.
2.7.2 Autodesk Navisworks
Navisworks Manage as defined by Autodesk Inc. is software that combines multidisciplinary design data into a single model for interference management and clash detection. This software can combine models created in AutoCad and / or Revit with the correspondent schedule developed in Microsoft Project, Primavera or Excel. The accuracy of the results will depend on the level of details included on the models. 14
There are available 3 types of Navisworks: 1. Manage 2. Simulate and 3. Freedom. Table 4 shows what is included in each one.
Table 4 Autodesk Navisworks types (Autodesk Inc., 2014)
15
3
MODELING NEW DEVELOPMENT IN URBAN AREAS
In the contemporary world cities are the center where the society focuses all kind of activities especially the related ones with administration and work. This fact makes the downtown of the cities particularly desirable for young people, workers and investors. To control and organize the cities, proper urban planning is essential. Urban Planning nowadays is a complex task that requires a comprehensive view of the phenomena that drive the growth. This process must include, not just the physical distribution in the space, also the economic, social and cultural aspects because all of them have great influence in the development of the cities. There are several disciplines that an Urban Planner should consider for example the geography, the administrative science and the law. Among all the economical science is the most important and inside this area the analysis of value of the terrain must be considered. Now, the value of the terrain of certain area is influenced by the number of people that desire that space and the government is part of the regulation of this process (Gonzalez, 2010). Tools that are currently used by urban planners in order to develop models that facilitate management and understanding are GIS and more recently CityGML, in the following sections a description of each of them is presented.
3.1
Geographical Information System – GIS
A well accepted definition of GIS is written by the National Center of Geographic Information and Analysis (NCGIA): "GIS is a system of hardware, software and procedures to facilitate the collection, management, manipulation, analysis, modeling, representation and display of spatially referenced data for solving complex planning and management”
Geographic Information Systems have become in the last decade, in essential working tools in urban planning and management of resources. Its ability to store, retrieve, analyze, model and map large areas with huge amounts of spatial data have placed them at the head of a large number of applications. Geographic Information Systems are currently used in the planning of land use, service management, ecosystem modeling, assessment and landscape planning, transport planning and infrastructure, marketing, visual impact analysis, infrastructure management, allocation of taxes, property analysis and many others (Al-Bukhari, 2008). GIS functionality includes entry, visualization and data Management also retrieving and analyzing information. 16
GIS considers the disposal, in layers (Figure 5), of its data sets. That feature makes possible to analyze thematic and spatial characteristics in order to obtain a better understanding of the area which facilitates the work of the urban planner.
Figure 5 Layering GIS (Burnaby, 2014)
In the figure above it is possible to see a clear example of the application of GIS system in a city, layers can be added containing relevant information like roads, parks utilities, etc. The most relevant GIS applications are:
Mapping locations: GIS can be used to map locations. It allows the creation of maps using automated cartographic, data capture and analysis tools. Quantitative maps: Population maps, which are used to locate places that meet specific demographic criteria and make decisions, or to see the existent relationships between different places. This provides an additional information level beyond the simple location maps used by the entities. Density maps: Although concentrations can be seen by simply mapping the locations of entities, in areas where there are many of them it becomes difficult to see which areas have higher concentrations than others. A density map lets you measure the number of entities in a uniform unit area, such as the meter or square kilometer, so that you can clearly see the distribution. Distance calculation: GIS can be used to know what is happening within a certain radius around an entity. 17
3.2
Mapping and change detection: GIS can be used to map the change in an area to anticipate future conditions, make decisions, and evaluate the results of an action or a specific policy (National Center for Geographic Information and Analysis, 1990)
City GML
Most of the information available about the new developments of the CityGML is related to the algorithms and programming languages used for it. Considering that this is not part of the scope of the project this overview focused in the definitions and uses of the cityGML. 3 Dimensional models of cities are commonly used just due to the visualization features. To better explode the potential of the models in fields like urban planning, environmental simulations, disaster management, etc. more information must be added to it. In order to combine objects and attributes CityGML was developed. To better understand the definition of cityGML is important to consider the definition of semantics: The general definition of semantics refers to the study of meanings-of the message behind the words. For this case, semantics means "from the user's perspective." And a semantic model is a set of representations that are interpreted for computer software allowing modeling an area of knowledge (The Data Administration News Letter, 2014).
CityGML (City Geography Markup Language) is a common information model XMLbased format used for the representation of 3D urban objects. . It represents semantics, geometry, topology, and appearance. Which means that it defines, not just features, also different relations for the most relevant topographic objects in the cities (Kolbe T., 2008) Figure 6 shows the modules in which CityGML is divided. The core, appearance, and generics are used to define the structures that are going to be applied to the thematic modules which are shown in the vertical bars.
18
Figure 6 Modularization of CityGML 1.0.0. (Kolbe T., 2008)
CityGML offers the possibility of create a model with different levels of details depending of the requirements of accuracy and data available. Thus, five well-defined consecutive levels of detail (LOD) are established to define the complexity of the 3D model. 1. LOD0: it is the roughest level. Consist basically in a 2.5D digital terrain model 2. LOD1: consist in the representation of buildings as blocks. It means the model does not include the shape of the roofs. 3. LOD2: it is more complete, the roof structures and larger building installations are represented in the model. 4. LOD3: It is a more architectural detailed model; it includes more complex structures like wall and roof shapes and textures, doors, windows, bays, vegetation and transportation objects. 5. LOD4: It complements LOD3 model adding the interior structures like apartment interior divisions, furniture, decoration, etc (Kolbe T., 2008).
19
Figure 7 CityGML Levels of detail (Kolbe T., 2008)
CityGML uses the ISO 19100 framework for the modeling of geographic features, which are defined as an abstraction of a real world phenomenon. Within virtual 3D models the cityGML includes for the semantics of the most important geographic features class definitions, normative regulations, and explanations. Another important concept of CityGML is CityObject. It is defined as the base class of all thematic classes; it includes the attributes name, description, and GML ID. Other abstract classes like BoundarySurface and its subclasses RoofSurface, WallSurface, GroundSurface, ClosureSurface, etc. are derived from class CityObject, as a consequence, starting from LOD2 they inherit its attributes and relations (Kolbe T., 2008). CityGML represents geometries of geographic features as objects and substructures. The volumetric geometries are bounded by a closed surface and all coordinates are in a world coordinate reference system (CRS) not allowing any local transformation. The advantage is that that each object belongs to exactly one fixed place in space allowing to create and maintain in an easier way spatial indexes in geodatabases (Kolbe T., 2008). CityGML offers 0D to 3D geometry aggregates and 1D to 3D composite geometries. Geometrical Level of Detail 0 (GLoD0): The object is represented by a planar surface within the model. It is considered that the elevation Z is a function of the horizontal position z=f(x,y), it means 2.5D representation. Geometrical Level of Detail 1 (GLoD1): The object is represented as a block in the model. No roof or surface details are shown. 20
Geometrical Level of Detail 2 (GLoD2): The object is represented with a well-defined contour closer to the one in the real world. Geometrical Level of Detail 3 (GLoD3): The representation of the object is exact to the one of the real world (Löwnera M. O., 2013).
Figure 8 Geometrical Level of Detail CityGML (Löwnera M. O., 2013)
Inside the model, one of the most important is the topological accuracy, the parts of the objects can touch each other but they cannot be in the same space, it means one space for every object. The CityGML follows the line of full decomposition of n-dimensional topological primitives into (n-1)-dimensional primitives, which again are decomposed down to the level of nodes (0D) (Kolbe T., 2008). Appearances (for example textures of the surfaces) are added to the semantics and spatial properties of the objects. They represent also categories like infrared radiation, noise, sunlight emission, etc those are named Themes and it works as analysis and visualization tool. Considering the necessity of exchanging or storing extra attributes or 3D objects that are out of the defined classes, cityGML considers 2 extensions: 1. The module "generics" contains generic city objects that can contain many additional generic attributes. 2. Application Domain Extensions (ADE)
3.2.1 Montreal CityGML
The geomatics division of Montreal City developed the downtown of the city a three dimensional model following CityGML international standards. The Model consists of a building modeling (Figure 9 – a.) and the topography of the terrain (Figure 9 – b.) on which aerial photographs are placed (Figure 9 – c.). Details of building roofs are captured by photogrammetric accuracy of a few feet and treated to match the international standard CityGML LoD 2. The topography of the soil 21
is expressed as a Digital Terrain Model (DTM) made from spot heights of elevation and different lines of constraints (Montreal City - Geomatics Division, 2014).
Figure 9 Montreal 3D Model (Montreal City - Geomatics Division, 2014)
The model is used by the city in applications like promotion of the Montreal built environment, presenting construction projects, the design and simulation of spatial urban territory. It is use also to analyze and better understand problems like road traffic, freight, runoff, noise levels, radio waves propagation limits, etc.
22
Figure 10 Representation of construction projects downtown Montreal – CityGML (Montreal City - Geomatics Division, 2014)
3.2.1.1 Data released by Montreal City
The city shared on its website data corresponding to the 3D model of Ville Marie neighborhood in downtown, with the public (donnees.ville.montreal.qc.ca/dataset/maquette-numerique-batiments-citygml-lod2avec-textures). The data can be used to promote the built environment present projects of urban planning, architecture, construction and design, simulate urban land or facilities used during public consultation or historical and academic research. For example it contributes to the thermal image analysis and feeding the mapping process heat islands, which can helps to simulate urban development scenarios, green roofs, dispersion of microparticles in the environment, etc. (Montreal City - Geomatics Division, 2014). In the mentioned website 19 files are available, Index and 18 more files (GML format) containing the following information: The digitized aerial photographs from 1930 to 2003; a digital base map comprising the geometric representation of the 2D elements of the territory made up of buildings, pavement, sidewalks, street furniture, trees, etc.; a digital terrain model (DTM) with a simplified representation of the topography of the terrain; and over 300,000 3D buildings (Union des municipalités du Québec, 2014). Now, the first challenge to overcome, if you are not professional, is to find a software/viewer to visualize the model. After consulting some forums and websites the first option is Global Mapper. A free trial version can be downloaded but it restrict the visual to just 4 files/maps and the textures cannot be uploaded either.
23
Figure 11 Montreal downtown Montreal downtown cityGML using Global Mapper
Second suggested option is, Snowflake GML viewer, and just the 2D map was visualized. The viewer is not user friendly, to access the tutorials payment is required and the Help option is not available for the free trial (Figure 12).
Figure 12 Montreal downtown cityGML using Snow flake GML viewer
ArcMap from ArcGIS software is another option, a free trial for a month is available, and the files can be opened showing the 2D drawings without textures, to visualize the full model 3D options are required and those are not available on the software unless you have a license.
24
3.3
Urbanization in Downtown Montreal
As part of the research, a small area in downtown Montreal (Ville-Marie neighborhood) between Drummond Street, Guy Street, Saint Catherine Street and Rue Saint Antoine O (see Figure 13) was chosen in order to analyze how many new buildings are under construction and how their development can impact the area.
Figure 13 Downtown Montreal Area of study (Google Maps, 2014)
In the mentioned area 10 new buildings were found, some of them are projects that are going to start soon, few are almost finished, the rest is currently under construction. After a visit to the sales office of almost every project, and checking the websites of each of them, the main characteristics of the buildings were collected and summarized in the Table 5.
3.3.1 Landscape change
Part of the purpose of this research was to add new projects to the downtown Montreal CityGML model in order to have a clear visual of the future landscape, but due to lack of information and inconvenient found about the software required for its use as explained in section 3.2.1.1, it was decided to use Google Earth (Figure 14). 25
Table 5 Main Characteristics Buildings Area of Study (Info provided by projects sales offices and its websites) No. Building Name
1
2
3
4
5
6
7
8
9
10
Address
Developer
1160 rue MacKay 1190 Mac kay Tyeon Montreal,Quebe c H3G 2H4 1205 Mackay Douze05 Street Mackay Montreal, Belcourt Condominiums Quebec H3G 2H5 1235 rue Flex Bishop Condominiums Montreal, Belcourt Quebec H3G 2E2 1155-1189 Ax is C on do s Company Bishop Street 1400 boul. BRIVIA GROUP René-Lévesque + T.G. BECO / O. Construction Destination YUL Montreal, SDK and Quebec H3G Associates + 1T6 Pageau Morel Condos Crecent
Icone
R oc ca bel la
L'Avenue
Tour Des Canadiens
1220 Crescent Street 1175 de la Montagne, Montreal, Quebec H3G 1Z2
Inca Development
www.condosma ckay.com/contac tfr.html
Estimated completion
July 2016
No. No. of No. of Parking storeys units spaces
Description
Prices- in thousands (From- No tx included) 1 2 Studio 3 Bed. Penthouse Bed. Bed.
Sales information
Parking
Gym, terrace, jacuzzi, 100% residential no commercial at ground level. Studios, 1, 2 or 3 bedroom
$55
$146
$180 $231
$284
-
In average price increases $5th per floor. Over 50% sold. /75% residents - 25% investors
20
158
116
www.belcourtcon dos.com/properti Delivered started es/douze052015 / will finish mackay2016 condominiums
11
129
29
Concrete building - studio, 1 or 2 bedroom units, exercise room, exterior roof top garden area with BBQ.
$55
$136
$171 $237
-
-
In average price increases $3th to $4th per floor. Over 50% sold. / 60% residents - 40% investors
www.belcourtcon dos.com/properti Completed es/flex-condos/
11
214
90
Concrete complex, comprised of 1 or 2 bedroom units, salt-water roof-top pool, exercise room and terrace.
$50
-
$154 $281
$451
-
In average price increases $3th to $4th per floor. Over 98% sold. /70% residents - 30% investors
axiscondos.ca/in december 2015 dex-en.php
9
58
31
Rooftop terrace, gym, jacuzzi, 1, 2 or 3 bedrooms
$55
-
$225 $367
$528
-
$55
$162 (+1th per floor)
$270 $397 $914 (+2th (+3th (+10th per per per floor) floor) floor)
$237 $305
destinationyul.co Spring 2017 m/en
38
900
320
Lobby, lounge, bar/reunion room, gym, pool, spa, sauna, Sky Lounge, terraces Studios, 1, 2 or 3 bedroom, penthouses and townhouses
www.condoscre scent.com/accue Winter 2014 il/
11
90
90*
Rooftop terrace, exercise room, studio, 1, 2 or 3 bedrooms
$55
$208
$55
$181 to $339
$1,600
The price increases aprox 1% per floor. The sales office just open. Price listed is the lowest one, it can vary depending on size and location of the condo. 60% sold. 70% residents and 30% investors. The project included 18 townhouses (from $1.6 M)
-
Over 65% sold. /50% residents 50% investors
$286 $421 $832 to to to $863 $500 $651
N/A
Over 75% sold. /75% residents 25% investors
$699
www.iconecondo Winter / Spring minium.com/201 2016 (first tower) 4/en/
38
358
358*
8th floor salt water pool, gym, sauna, whirlpool, yoga room, terrace. Studio, 1, 2 or 3 bedroom units and 2 full floors of penthouses
1300 Boulevard René-Lévesque Ouest, MC Finance Montreal, Quebec
www.roccabella. Fall/Winter 2015 ca
40
592
500
Gym, BBQ, pool, party room, Jacuzzi, theater room, terrace, conference room, spa, 1,2 or 3 bedrooms, penthouse.
$60
-
$343 $539 $1,260
N/A
*$2000 + per upper floor + tx/ condo fees $470 + fix tax (≈$500 monthly)
Avenue des Broccolini and Canadiens-Rue Carttera Private DrummondEquities Montréal, QC
www.lavenuecon Fall / Winter dos.com/ 2016
50
303
243
Media room, cabanas, sauna, party room, pool, indoor pool, exercise room, terrace, lounge
$55
N/A
$379 $300 to $595 to TO $1,31 $2,401 $410 0
N/A
Price listed is the lowest one, it can vary depending on size and location of the condo. 85% sold. 60% residents and 40% investors.
Club De Hockey Canadien, Canderel tourdescanadien Fall / Winter Residential, s.com/en/ 2015 Cadillac Fairview Corp. and Fonds de Solidarité FTQ
50
552
N/A
Party Room, pool, terrace, gym, BBQ area, business centre, yoga & pilates studio, spa, Studios, 1, 2 or 3 bedroom, penthouses
$60
$170
$360 $544 $1,430
N/A
Sold out
Rue de la Montagne & Avenue des Canadiens-deMontréal
Metropolitan Parking / construction performed by SNC lavalin
Web site
* The seller is not sure of the exact number but an approximate value was provided
26
a.
b.
Figure 14 Comparison study area 2010 (a.) and 2013 (b.) (Google Earth, 2010 - 2013)
27
The numbers in Figure 14 correspond to the project described in Table 5. It is possible to see, that buildings like Douze05 Mackay (1) and Condos Crecent (6) are already under construction but the picture was taken before then the change is not reflected. 1190 Mackay (2), Axis (4), Destination YUL (5) have just the sales office, it means the construction has not started yet. Flex Condominiums (3) is finish and Icone (7), Roccabella (8), L'Avenue (9) and Tour Des Canadiens (10) are under construction. Something that is really important is that almost the new buildings are going to replace parking lots, this will drastically change not just the landscape it will increase the population and traffic which in turn will increase the pollution. According to “The Globe and Mail” diary Montreal, by the end of 2013, had two times
more condominiums for sale than Toronto (the largest city in Canada) and the number is increasing. The supply of condos for sale rose 47% over the 2011 levels. There are several reasons for this increase, lack of land, some land-use policies that
The numbers in Figure 14 correspond to the project described in Table 5. It is possible to see, that buildings like Douze05 Mackay (1) and Condos Crecent (6) are already under construction but the picture was taken before then the change is not reflected. 1190 Mackay (2), Axis (4), Destination YUL (5) have just the sales office, it means the construction has not started yet. Flex Condominiums (3) is finish and Icone (7), Roccabella (8), L'Avenue (9) and Tour Des Canadiens (10) are under construction. Something that is really important is that almost the new buildings are going to replace parking lots, this will drastically change not just the landscape it will increase the population and traffic which in turn will increase the pollution. According to “The Globe and Mail” diary Montreal, by the end of 2013, had two times
more condominiums for sale than Toronto (the largest city in Canada) and the number is increasing. The supply of condos for sale rose 47% over the 2011 levels. There are several reasons for this increase, lack of land, some land-use policies that favoring densification, low interest rates, cheaper financing for developers, immigration policies and cultural change. (Rabidoux, 2013). According to the information collected in the sales offices, and averaging between all buildings, it is possible to say that about 70% of buyers are Canadian residents and 30% are investors, and from those numbers apparently people from China are the largest group of foreign buyers. Some of the reasons why foreign people is attracted to buy in Montreal can be because of its European style, others because they found than the prices are lower than Vancouver or Toronto or they just one a second place as an investment. One of the concerns due to this condo-boom is the increase on the prices of the units, and that may be Canadian citizens will not be able to afford them. Another problem could be generation of a downturn if the market crashes.
3.3.2 Traffic impact
As mentioned above, something that will cause an impact in the traffic of the downtown of the city is the fact that all the buildings (but Tour Des Canadiens) are going to replace parking lots. Making use of the picture taken by Google earth in August 2010, the approximate maximum capacity of the parking lots to be replaced was estimated and a comparison between the expected numbers of parking lots is shown in Table 6.
28
Table 6 Building Parking spaces Vs. Parking lots spaces
No.
1 2
3 4 5 6 7 8 9 10
Building Name
No. of storeys
No. of units
No. Parking spaces in the building
Approx. No. Parking spaces in the parking lot
1190 Mackay Douze05 Mackay Condominiums
20
158
116
75
11
129
29
60
Flex Condominiums Axis Condos Destination YUL Condos Crecent Icone Roccabella L'Avenue Tour Des Canadiens
11
214
90
160
9
58
31
40
38
900
320
285
11
90
90
50
38 40 50
358 592 303
358 500 243
140 280 155
50
552
442
0
Total
2219
1245
*Assumed to be 80% of the units number
Looking at the numbers in the table, and considering the approximations made, it is possible to see that the number of cars is going to be almost the double once the projects are completed. According to a report made by Martin Turcotte for Statistics Canada, the percentage of population aged 18 and over making all trips by car (as a driver or passenger) on the reference day, by census metropolitan area (CMA / Metropolitan area boundaries used in the 2005 General Social Survey are those established in the 2001 Census) are above 70%. Now assuming that the parking lots will function at its 70% capacity all the time, we can sustain that the increase in traffic in downtown will be 50% on the next 2 years.
29
4
4.1
Case of study “Roccabella”
General information
Roccabella is a new condominium building comprising 592 units divided into two 40storey towers each one housing 298 units. The project is located on boulevard RenéLévesque, between de la Montagne and Drummond, the exact address is 1300 Boulevard René-Lévesque west (see Figure 15). This area is in downtown Montreal, close to Bell Centre, and subway stations Peel, Stanley, Lucien L’Allier and GuyConcordia.
Figure 15 Project Location (Google Maps 2014)
The building has 5 levels of indoor parking, commercial areas in the 2 first levels, gym, BBQ, pool, party room, Jacuzzi, theater room, terrace, conference room, spa, 1, 2 or 3 bedrooms units and penthouses. The smaller unit has an area of 763 square feet, and the penthouses have, for their part, an area up to 2,600 square feet. The prices for the apartments and other characteristics of the building are shown in Table 5.
30
The team that makes this project possible is comprised of: 1. MC Finance: It is the real estate developer. The headquarters are located on 2160 de la Montagne, downtown Montreal. 2. Béïque Legault Thuot Architectes (BLTA): It is the firm in charge of the architecture and design work. The company was established in 1970. It offers design services such as high-rise buildings, building envelope, heritage restoration, and sustainable design. They work mainly with private clients from commercial, residential and hotel sectors. This firm was also in charge of the design of Icône (two buildings of 39 and 26 stories), Univers (two buildings of 35 and 45 stories) and le Triomphe (20-storey building) all of them located in downtown montreal (Béïque Legault Thuot Architectes, 2014). 3. Magil Construction: It is the general contractor. Magil is a privately held construction company that works within Quebec and British Columbia. April 2, 2009, Magil Construction was acquired by Fayolle Canada and joined the MC Group. MC Group organization maintains revenues in excess of $400 Million making it a top 10 contractor in the country (Magil Construction, 2014). 4. NCK: structural engineers. Established in Montreal in 1969 under the name of Nicolet, Chartrand, Knoll, the firm is specialized in structural engineering and it has been part of the design of hundreds of important buildings and structures in Canada and abroad (NCK, 2014). 5. AECOM: mechanical and electrical engineers. Founded 20 years ago by Richard G. Newman and some employees of Ashland Inc. AECOM is an integrated infrastructure and support services firm, with a broad range of markets, including transportation, facilities, environmental, energy, water and government (AECOM, 2014).
4.2
Developing Roccabella model in Autodesk Revit
Roccabella, according to Kristi Ante (architect from Magil Construction Corporation), was design using the traditional 2D method. The drawings were done in AutoCAD. Magil construction generously provided us 56 drawings in DWG format containing architectural and few structural details. The most relevant are the following ones: 1. 1st level basement; 2. 2nd level basement; 3. Typical basement on 3rd & 4th floor; 4. 5th level basement; 5. Ground floor; 6. Mezzanine level on ground floor; 7. 2nd level; 8. 31
mezzanine on 2nd floor; 9. 3rd floor; 10. Typical floor from 4th to 32nd floor; 11. 32nd floor; 12. Typical floor from 33rd to 39th; 13. Penthouse on 40th floor; 14. Sheds on 41st & 42nd floor; 15. Shed on 42nd floor; 16. Main roof and shed type; 17. North elevation; 18. Elevation of rooftop structure. The complete model was developed by three different students: First 3 levels were developed by Camila Omori, forth to thirty second level by Maria Malpica and thirty third to last level by Xue Bai. The procedure that follows corresponds to the model for the forth to thirty second level. Student licensed version of Revit Architecture 2014 was downloaded from Autodesk’s
student community website to create the 3D model. Taking advantage of the compatibility of AutoCAD and Revit, the first step is importing the dwg. file to Revit using the "Import CAD" option. After importing the file, the process starts by drawing the walls, and there is when we faced the first difficulty. The information available was not enough, the details of the apartments were not included, and also important features like material of the walls, type of windows, doors, etc, was not clear. Therefore the first assumptions were made: the walls were selected as a generic type, regardless of the materials, the covering of the structural elements was drawn as a generic wall as well (Figure 16). The details for the apartments were taken from the Roccabella website, but since those drawings are for marketing purposes some measures are missing, some of them are not exactly matching the design drawings (see Figure 17). Regarding the envelope of the building, it was not clear if just curtain walls were used, so a combination of curtain wall and generic walls were used as shown in the figure bellow.
32
Figure 16 Roccabella typical floor: Walls drawn on top of the CAD file and first assumptions made.
As mentioned this figure shows some of the main assumptions taken, for example, to better understand, in the left top corner it is possible to see different kind of walls available in the software, and the one that was chosen. These kinds of decisions are very important because maybe the physical appearance will not be drastically affected but features like quantity takeoff can vary enormously.
33
Figure 17 Example of differences between unit C1 on the website and the design drawings
Once the envelop and interior structure are defined, the next step is adding details like the doors, windows, railing, ect. (Figure 18) The final touch for the main floor is adding furniture and/or appliances in order to facilitate the differentiation of the rooms with the living room, kitchen, bathroom, closets, and laundry room. Some of them can be found in the software using the “place a component” option and if required loading families available on Revit.
Other accessories, like for example showers, stoves, bathtubs, washing machines, etc. were downloaded from websites of the suppliers (Figure 18).
34
Figure 18 Adding details to the model
Now, the next step is adding the slab and creating the levels up to the 32, when the last part or the building begins. This process was done drawing the levels and after it just using the “copy” and “paste”
options (Figure 19). The problem faced with this procedure is that the model becomes too heavy making it very slow. The most likely cause is that the furniture and small details added before are too much for this stage of the process.
35
Figure 19 Cross section of the Roccabella model 3 to 32 levels.
As mentioned before, the complete model of the tower was developed by 3 different people. When the whole model was tried to put together the first inconvenient was to make all the files matching. The different parts of the model were developed in separate and independent files (no related one to another) so unifying them was very complicated. Then as a result of lack of details in the initial drawings and lack of communication the assumptions made for each person were not the same making the final product inaccurate and with an external appearance different between the typical levels and the rest, even after several efforts to unify it, the differences are visible, as it can be appreciate in the figure below.
36
Evident Differences
Developed by Xue Bai
Developed by Maria M.
Developed by Camila O.
Figure 20 Complete Tower. Differences between the levels.
4.3
Developing 4D model of Roccabella.
After developing the 3D model in Revit, the use of Navisworks Manage 2014 is required to link it with the schedule. It is important that the 2 software are from the same version. The first trial was using Navisworks Manage 2015 and it was not possible to import the model. The schedule used was created and divided by building levels using Microsoft Project and then it was imported to Navisworks. Initially the 3D model was imported from Navisworks directly from Revit, but the resulting model was not including the elements of the building by levels, making the linking process impossible.
37
The issue was fixed downloading Add-Ins plugin to Revit and exporting the model to the other software. The process of linking the schedule can be automatic if the components of the building are numbered level by level in Revit when drawing them and corresponding to the items on the schedule. In this case the linking was made element by element, because the numbered was not included and the 3D model was completed not level by level, instead copy paste option was used. The process can be seen in the figure sequence below:
a. Imported schedule and 3D model
b. Linking schedule with the building elements
c. and d. Time simulation Figure 21 4D process in Navisworks Manage 2014
38
5
CONCLUSIONS
BIM is a powerful that enables a better management of constructions projects. In order to create a BIM that can be use from the design phase through the life cycle and until disposal, greater collaboration between owner, designer and contractors is required. Once the use and copy right of the information shared is regulated, benefits like for example great visualization, easier way to perform changes, cost estimating, cost and time control, are evident. By performing the exercise of developing a BIM model as a part of a team allowed us to better understand the process, the benefits, the challenges, learn from mistakes and the value of communication and information sharing.
BIM is devoted just to the building environment. in order to enlarge its application the models can be converted to IFC in order to facilitate interoperability. In the field of GIS, city models are based on GML and particularly in CityGML, which allows representing the entities that make up a model of urban landscape and even the exterior and interior details of the buildings.
REFERENCES
AECOM, 2014. www.aecom.com. [Online]. Al-Bukhari, I., 2008. Multi-Level GIS-Based Data Management Model, s.l.: s.n. Autodesk Inc., 2014. www.autodek.com. [Online]. Autodesk, 2014. Autodesk Revit: Implementation in Practice, s.l.: s.n. Béïque Legault Thuot Architectes, 2014. www.blta.ca. [Online]. BuildingSMART International home of open BIM, 2014. www.buildingsmart-tech.org. [Online]. Burnaby, 2014. www.burnaby.ca. [Online]. Dixit, V. C., 2007. 4D Modeling: Adding a New Dimension to CPM Scheduling. AACE, s.l.: s.n. 39
Eastman C., T. P. S. R. L. K., 2011. BIM handbook: A guide to building information modeling for owners, managers, designers, engineers and contractors. s.l.:s.n. ESRI, 2014. www.esri.com. [Online]. Fan H., M. L. J. M., 2009. Generalization of 3D Buildings Modelled by CityGML. Fernandes, 2013. Advantages and Disadvantages of BIM Platforms on Construction Site. Gonzalez, L., 2010. Urban Planning and Spacial-Economic Aspects, s.l.: s.n. Google Earth, 2010 - 2013. Google Earth. [Online]. Google Maps, 2014. www.google.ca/maps. [Online]. Hergunsel, M. F., 2011. Benefits of BIM for Construction managers and BIM base scheduling, s.l.: s.n. Inside-the-factory, 2014. insidethefactory.typepad.com. [Online]. Kolbe T., G. ,. C. A. N., 2008. OpenGIS® City Geography Markup Language (CityGML) Encoding Standard. s.l., s.n. Löwnera M. O., B. J. G. G. H. K. H., 2013. New Concepts for Structuring 3D City Models – an Extended Level of Detail Concept for CityGML Buildings. Magil Construction, 2014. www.magil.com. [Online]. McKinney, K. K. J. M. F. &. H. C., 1996. Interactive 4D ‐CAD. Computing in Civil. Montreal City - Geomatics Division, 2014. La maquette numérique 3D intelligente du centre‐ ville de la Ville de Montréal. [Online]. Mrasbuilt, 2014. mrasbuilt.com. [Online]. National Center for Geographic Information and Analysis, 1990. www.ncgia.ucsb.edu. [Online]. NCK, 2014. ww.nck.ca. [Online]. Precise Drafting Inc, 2014. www.precisedraftinginc.com. [Online]. Rabidoux, B., 2013. Is Canada’s condo boo m coming apart at the seams?.
Reinhardt, J., 2009. The Contractor's Guide to BM. 2nd edition. s.l.:s.n. Roccabella, 2014. www.roccabella.ca. [Online]. S. Azhar, M. H. B. S., 2011. Building Information Modeling (BIM): Benefits, Risks and Challenges. Sanveo, 2014. www.sanveo.com. [Online]. 40
