Bim report w14002246

BIM

and sustainability BIM: A definition.

Reasons for using BIM. BIM software: A brief history.

BIM, sustainable design and the environment.

Advantages BIM offers to sustainable design.

Waste elimination.

Selecting the optimum building orientation.

Daylighting.

Daylighting case study.

Student Number: W14002246.

Programme Study: Architectural Technology.

Academic Year: Final Year 2016/2017.

Module Name: BE1338 – Information Management.

Tutor Name: Dr. James Charlton.

Word Account: 3234 Words.

Date of Submission: 12/12/2016.

Modelling energy consumption.

CONTENTS 07 Introduction

08 08

BIM: A definition

Reasons for using BIM

09 BIM software: A brief

history

11 BIM, sustainable design and the environment.

12 13 Waste elimination

Advantages BIM offers to sustainable design.

Improved decision-making. 12 Improved analytics. 12 Improved data accessibility. 12 Simplification of the certification process. 13

14 Selecting the optimum building orientation Orienting using the sun. 14 Importance of orienting correctly. 14 Selecting the right materials to support the orientation. 15

17 Daylighting

20 Daylighting case study The American Canyon High School 20

24 Modelling energy consumption

24 Conclusion

26 References

CONTENTS

BIM AND SUSTAINABLITY

Introduction Currently, the building industry’s latest catchword is ‘sustainable design’; however, many ideas and descriptions have been formulated about the term, meaning it is important to establish what it actually is and how it integrates with Building Information Modelling (BIM). A building’s sustainability depends on several criteria

such as how efficient it is at saving energy, i.e. water etc.

This study’s purpose is to examine how BIM helps engineers to integrate sustainable design into their buildings early in the design process through the introduction of green initiatives, meaning their mechanical systems are more efficient and proportionate.

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BIM: A definition

Reasons for using BIM

BIM is a technique that creates a 3D model of a building; this is then used to formulate and convey decisions that affect the project.

Software such as Autodesk BIM is an effective tool for giving a project’s stakeholders a clear idea of its progress as it involves everyone in the collaboration, design, simulation, and visualisation throughout the construction process.

With BIM, meeting business and project goals is greatly simplified (Autodesk, 2016).

The most sophisticated BIM software uses the ‘product models’ concept, which vastly improves control over the various processes by, for example, enhancing the quality of information and improving data management protocols etc. Although describing a general process, the key word in the term ‘Building Information Modelling’ is ‘information’, as it is by creating a BIM model/product model that the architects and other stakeholders are able to share information, check for discrepancies, and collaborate more easily. For instance,

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every drawing is outputted automatically via the information model; meaning each plan, elevation, section etc. is automatically generated and updated constantly. In addition, BIM can be used to calculate bills for materials, work out estimates, and create doors and windows schedules as part of a rooms list; while for architects, BIM frees them to concentrate fully on the design part of the project.

Additional tools allow more sophisticated simulations and estimations to be made, such as energy consumption and CO2

emissions, as well as replicating the airflow, sounds and shadows/sunlight within a building.

However, more simulations mean greater demands on the model’s ‘objects’, which the architects and engineers use to fill the model with.

Thus, it is necessary that all product specific data is available early on in the process as accurate visualisations help with issues such as estimating the building’s expected energy consumption or making functional analyses (BIMobject, 2013 ).

BIM software: A brief history It was in the late 1970s/early 1980s that the first building modelling software tools became available. They included programs such as Chuck Eastman’s Building Description System, GLIDE, Reflex, RUCAPS, and Sonata, and both the applications and equipment

needed to work them were expensive. Thus, take up was limited.

However, in 1984, ArchiCAD launched Radar CH, the first software able to run on PCs. Nevertheless, collecting all the relevant information BIM needs for each building project is complicated, and so several companies have commissioned their own software specifically tailored to work with the BIM system. Examples include AECOsim Building Designer, Allplan, ArchiCAD, Autodesk Revit, MagiCAD, Synchro PRO, Tekla Structures, and Trimble SketchUp. Moreover, these stand apart from other architectural drawing programs such as AutoCAD because they let extra information, i.e. costs, timescale, sustainability and maintenance data, and manufacturers’ details, to be factored into the building model (Quirk, 2012).

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BIM, SUSTAINABLE DESIGNE AND THE ENVIRONMENT

BIM, sustainable design and the environment.

BIM’s greatest asset for sustainable building design is its analytical capabilities. Constructing a sustainable building relies on collecting accurate data into how a structure will perform in the real world through scrutinising and improving the design. However, calculating a building’s performance using traditional CAD/object-CAD tools is time-consuming and expensive because it requires large amounts of human interpretation and intervention. BIM, on the other hand, gathers most of the supporting analytical data as the project progresses. This means that even at the earliest stage, the designers can

begin to monitor how the building will perform; they can then quickly formulate alternative designs and improve their decision-making to make the design more environmentally friendly. Through rationalising the process’ analytical and design parts, BIM is then able to make the calculations required to maximise the building’s performance (Middlebrooks, 2008).

Figure 1: BIM rationalizes the analytical and design processes, which helps the designers to speed up their evaluation and decision-making, meaning their designs are more environmentally friendly.

BIM models also contain a host of other data relevant to sustainable design solutions. It has, for example, the capability to generate detailed drawings directly using the model (these are then automatically synchronised by the software), which increases the accuracy and effectiveness of any green certification.

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Additionally, quantities of building materials can also be derived from the model, which allows calculations to be made about the likely percentages of material that will be recycled, reused, and/or salvaged.

Indeed, the system can compare several sustainable design options and automatically track each one.

Furthermore, advanced visualisation tools can be utilised to study factors

such as solar effects and to generate 3D images and animations of the project, which in an environmentally friendly (green) partnership (i.e. architects, owners, consultants, building inspectors etc.) is an effective way to gain insight and promote a collaborative communication culture (Middlebrooks, 2008).

Advantages BIM offers to sustainable design.

As BIM lets architects construct a digital/prototype model of their project prior to the start of any physical construction, the system offers a number of advantages for sustainable building design. Its four main benefits are: Improved decision-making — Throughout the design process, various building options need to be considered and the architects have to be informed enough to choose the most appropriate. Using BIM, architects can study several design variations with just one model. The options can be activated and analysed before either being accepted as part of the final design or rejected (Salih, 2013).

Improved analytics — As it is equipped with high-resolution graphics capabilities, a 3D modelling interface, and high quality detailing, BIM can easily generate a precise digital model for any sustainable building scheme. Moreover, the digital model is very useful for identifying discrepancies, and analysing whether the amount of materials should be reduced. Indeed, because creating BIM models is so cost-effective, fast, and simple, architects generate multiple variations of a design so they can compare like for like before choosing the most appropriate, environmentally friendly one. Using BIM effectively gives an accurate reading of how sustainable a building will be before construction begins (Salih, 2013).

Improved data accessibility — The BIM system provides architects and designers with an easy way to access the data they need to create sustainable buildings. This is because its sophisticated software is capable of processing data quickly, which makes any changes simple.

For example, estimating the quantities of the building materials necessary to finish a project is easy and accessing any other data is equally problem-free (Salih, 2013).

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Simplification of the certification process — As a BIM model contains all the relevant data concerning how sustainable its design is, this improves the veracity of its green certification. In addition, because BIM can automatically track the type and quantity of the required building materials, it is easy to find out how much can be recycled or reused (Salih, 2013).

Another advantage of BIM is that it creates a single contact point for the various stakeholders, which is useful when trying to effectively deliver a sustainable design. Indeed, now may the right time to embrace BIM as the main tool for designing and delivering sustainable building projects (Salih, 2013) as according to McGraw-Hill Construction, in 2015, the American green building market was set to be worth approximately $135 billion.

Waste elimination As well as assisting with designing and measuring a building’s environmental performance, BIM’s greatest strength lies in the contribution it makes to sustainability through eliminating the waste buildings generate throughout their lifecycles. Indeed, waste is an inherent problem for the construction industry, which is reflected in a report published by America’s National Institute of Standards and Technology (NIST) in 2004. The report calculated that 30% of building costs were incurred through factors such as flawed designs, modifications, inadequate reviews and analyses of designs as they developed, poor risk assessments, weak logistical planning, and inadequate levels of communication between those responsible for managing and maintaining the finished structure. Moreover, every modification, inefficiency, poor co-ordination, undetected mistake, and badly managed/inefficient maintenance procedure that occurred on site increases the construction’s carbon footprint (bdonline.co.uk, 2014).

Basically, BIM’s prime function is to collate into a single model all the information about the design and construction particulars provided to it by the various stakeholders. This allows any conflicts to be identified easily and considerations such as managing the building’s facilities throughout its lifecycle can be integrated into the model at the beginning of the process. Co-ordinating the information like this means that excess carbon consumption can be anticipated and counteracted (bdonline.co.uk, 2014).

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Selecting the optimum building orientation An important part of building design is considering where the structure will be positioned relative to the transit of the sun. Indeed, architecture firms such as AEC Associates, who offer a CAD design and drafting service, place great emphasis on this aspect of the process because even though a building may only occupy a set space, it is integral to the environment in which it is located. Using CAD design and drafting tools can ensure that a building is correctly oriented so that it takes full advantage of the available natural resources (AECassociates, 2016).

Orienting using the sun — As the sun is in constant transit, it is necessary to consider several factors when designing a building for a specific location. This is because the sun’s position alters depending on the latitude, and time of day/year etc.; thus, if architects are knowledgeable about solar behaviour this helps them design façades that allow in the necessary amounts of sunlight and heat for the building’s requirements. In addition, correct orientation decreases the chances of the building overheating and giving off glare (AECassociates, 2016).

Figure 2: Architectural CAD Design and Drafting Services: Building orientation.

Importance of orienting correctly — Orienting a building correctly is essential as it helps to save valuable resources, which is increasingly important nowadays as traditional energy resources dwindle. Indeed, if correctly aligned, a building’s façade can take full advantage of the available natural light, thus reducing the use of artificial lighting, which will cut electricity bills and conserve energy resources. The CAD drafting tool can also modify the

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façade’s design depending on how the sun and wind behaves to meet the building’s heating and cooling requirements (AECassociates, 2016).

Selecting the right materials to support the orientation — Glazing and other materials used in the building should all be carefully chosen so that they support the structure’s orientation. For instance, as certain orientations may expose a building to too much solar activity, using the right materials can limit overheating and/or store any excess heat/light for use later when the sun has set. Elevations that face the equator, therefore, are ideally positioned to exploit the power of the sun and can capture and store heat and light via large windows and through using materials with a

high thermal mass, while elevations that do not are unsuitable for this.

Moreover, so that temperature fluctuations can be minimised when the sun rises and sets, east-facing elevations would probably benefit most from being fitted with large expanses of glazing to maximise the amount of direct solar heat they are exposed to. West-facing elevations, though, would probably be better fitted with smaller windows and incorporate more high thermal mass materials into their structure, which would allow heat to be absorbed that could be used during the night. Choosing the appropriate configuration is dependent on the environment (Autodesk University Workhop, n.d.).

Figure 3: Increased glazing on the east-facing elevation and greater thermal mass on the west-facing side can even out temperature fluctuations.

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DAYLIGHTING

Daylighting ‘Daylighting’, i.e. illuminating buildings using natural light, not only significantly reduces the demands made on the electricity, heating and other energy resources, it also improves people’s comfort and productivity. Thus, a building with a sustainable, high performance design specification can achieve its objectives by effectively harnessing and incorporating the sun’s energy into its physical structure through features such as how its fenestration is arranged. Moreover, utilising BIM to work out the sustainability of a building is invaluable, with software such as Daysim, Ecotect, and 3ds Max Design able to analyse how much daylight the structure is likely to be exposed to. Alternatively, a physical model could be created and positioned in situ so that levels of daylight could be measured, or a separate digital model could be generated and used for analysis.

Obtaining accurate readings from these methods is time-consuming; however, now that the BIM model

can be imported into the new software programs, not only is the process quicker, it is more accurate because all the materials etc. can be put directly on to the model.

Frontages and curtain walls, for example, can be modelled to their exact dimensions, and windows positioned precisely (Moakher and Pimplikar, 2012).

Once all the information has been imported into 3ds Max Design, for example, the software will identify all of the model’s geometric data and the majority of the assigned materials. It is possible at this stage to make modifications to the materials, alter glazing specifications, and adjust several other features such as the reflective and refractive values etc. The software also takes account of the building’s interior, allowing designers to adapt various elements to enhance the eventual occupants’ visual experience. It is crucial that the feedback from the daylight analysis is accurate as each of the materials has a precise reflective/refractive value that must be factored in to the design (Moakher and Pimplikar, 2012).

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One method of importing a BIM model into a daylight analysis program is as follows: firstly, generate a model of the building using, for example, Revit, ideally with the window positions and interior spaces marked out so that it is ready to be analysed. The first evaluation can be made once the cameras, accurate weather data, and the daylight software have been set up. This is a streamlined energy modelling approach that uses BIM solutions to quickly assess and estimate a building’s projected energy consumption. Although it uses less initial information within a short timeframe and limited budget, building designers are still able to formulate expectations about how the building will perform and pinpoint areas that need improvement (Moakher and Pimplikar, 2012).

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The American Canyon High School

Daylighting: A case study In this study, it was the BIM model that had the greatest influence on how the daylighting issue was resolved. Even though daylighting is an important consideration in every building project, it is especially so for schools where evidence shows that improving daylight capacity leads to improvements in student learning outcomes.

Therefore, daylighting was an essential consideration when designing each of the classrooms, which was done alongside the designs for the solar shades. To help with the development of these shades, the ArchiCAD BIM model was imported into Ecotect and assessed for issues such as acoustics, airflow, daylighting, shading, and thermal performance etc. One part of the assessment studied how sunlight was reflected off the outer sunshades and diffused in the room. As can be seen in figure 5, the amount of light can be controlled, simply by adjusting the sunshades depending on the time of day and/or season (Yoders, 2009).

Figure 4: The American Canyon High School.

Figure 5: The exterior sunshade/lightshelf with transluscent daylighting glass in the transoms.

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Figure 6: The building orientation, which was configured to provide a balanced light source and to include as many north- and south-facing windows in each classroom as possible, along with skylights and clerestory windows so that light was directed into the corridors and lobbies.

BIM was also used to calculate the configuration of the sunshades.

These were included in the earliest designs and added to all the exterior southern, eastern, and western facing windows to control both glare and overheating. The BIM enabled the sunshades to be designed for a particular set of conditions, which was achieved using the Ecotect Solar Tool (an autonomous software capable of assessing specific shading conditions). Next, a simple model of the window was generated to which a variety of horizontal and vertical sunshade arrangements were added and manipulated. As each different configuration was tested, the Ecotect software created a series of realtime diagrams, which illustrated how much shade the window would receive on any day and in any season. Obviously, this makes it easy to compare a number of shading options before a final decision is taken about which to install. In addition, the sunshades’ levels of performance, price, maintenance, and aesthetic appeal were also taken into account (Yoders, 2009).

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Figure 7: Shading diagram.

Figure 8: Sunshade configuration.

This is just an illustration of a number of ways BIM applies its quantitative assessment ability to differing design situations in order to enable better decision-making between the designers.

Importantly, the BIM tools used in the examples acted as a guide and in no way supplanted or coerced the design process. However, it is commonly acknowledged that BIM’s ability to assist designers make more informed choices acts as a powerful aid for creating more sustainable buildings (Yoders, 2009).

Figure 9: A class in side the school.

Figure 10: The main Gate

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Modelling energy consumption

Modelling energy consumption Estimates say that approximately 40% of the overall energy consumption and CO2 emissions generated within the EU is caused by the energy used to power its buildings. In the UK, meanwhile, almost 50% of emissions are generated this way. However, designers can use the information provided by BIM to improve their buildings’ energy efficiency through, for example, the introduction of smart technology, which would help reduce energy wastage such as heat loss. In addition, these measures should result in the reduction of a building’s energy needs, which could mean scaling down the services/facilities it requires to function. These services/facilities could be supplied either in situ or come from independent sources as happens with low-carbon technology (Hyde, 2013).

One type of low-carbon energy supply is the Combined Heat and Power (CHP) system, which can be used either in situ or centrally , and generates heat and electricity from a single source. Combining the data from the models, BIM, and energy profiles so that an accurate assessment can be made about a building’s energy needs means that a CHP system can be configured to best meet those specifications. Thus, its performance can be optimised to deliver energy more cheaply and with fewer carbon emissions (Hyde, 2013).

Conclusion Increased appreciation about how buildings and their infrastructures adversely affect the environment has made the construction industry aware that it has to adopt sustainable design initiatives. Indeed, sustainable design, which works by demanding a lot of information in the earlier stages of a design, is the main driver of progress within the industry, and BIM is ideally place to facilitate this as its capabilities allow an integrated design workflow system that connects the design and analysis processes to be set up. Thus, as the construction industry becomes more familiar with BIM, building designs and their end products will become evermore buildable, precise, predictable, and, importantly, sustainable. This will lead to the design and delivery of cost-effective, resource-efficient, environmentally friendly structures that reduces the built environment’s carbon footprint.

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BIM AND SUSTAINABILITY

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References • AECassociates (2016) Insourcing within a CAD design and drafting services firm.

[Online] Available at: http://theaecassociates.com/articles/cad-design-and-draftingservices-importance-of-building-orientation/ (Accessed: 4 December 2016).

• Autodesk (2016) Building Information Modelling. [Online] Available at: http://www.autodesk.co.uk/solutions/building-information-modeling/overview (Accessed: 4 December 2016).

• Autodesk University Workshop (no date) Massing and orientation for heating.

[Online] Available at: http://auworkshop.autodesk.com/library/building-

science/massing-orientation-heating (Accessed: 4 December 2016).

• Bdonline.co.uk (2014) CPD 7 2014: BIM and sustainability. [Online] Available at: http://www.bdonline.co.uk/cpd-7-2014-bim-and-sustainability/5067059.article (Accessed: 4 December 2016).

• BIMobject (2014) BIMobject — Why BIM. [Online] Available

at: http://info.bimobject.com/why-bim (Accessed 4 January 2015).

• Hyde, J. (2013) How Building Information Modeling (BIM) Can Improve Future

Energy Consumption. [Online] Available at: http://chpblog.energ-group.com/howbuilding-information-modeling-bim-can-improve-future-energy-consumption (Accessed: 4 December 2016).

• Middlebrooks, R.E. (2008) Sustainable Design Through BIM and Analysis. [Online] Available at: http://hpac.com/fastrack/Sustainable-Design-Through-BIM-andAnalysis (Accessed: 4 December 2016).

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• Moakher, E.P.E. and Pimplikar, S.S. (2012) ‘Building Information Modeling (BIM) and Sustainability — Using Design Technology in Energy Efficient Modeling’, in IOSR Journal of Mechanical and Civil Engineering, 1(2), pp. 10–21. DOI: 10.9790/1684-0121021.

• Quirk, V. (2012) A Brief History of BIM. [Online] Available at: http://www.archdaily.com/302490/a-brief-history-of-bim (Accessed: 4 December 2016).

• Salih, J.N. (2013) BIM and Sustainable Design. [Online] Available at: http://buildipedia.com/aec-pros/design-news/bim-and-sustainable-design (Accessed: 5 December 2016).

• Yoders, J. (2009) BIM school, green school: California’s newest high-performance

school. [Online] Available at: https://www.bdcnetwork.com/bim%C2%A0schoolgreen-school-californias-newest-high-performance-school (Accessed: 5 December

2016).

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