Leveraging BIM for sustainable design

by Elaina Adams | December 1, 2011 10:23 am

By Caesar Ruest, Sarah Hodges, and Darren Dambly
The building sector accounts for 30 to 40 per cent of global energy use, making it the largest annual contributor to greenhouse gas (GHG) emissions. (This statistic comes from work conducted by the United Nations Environment Programme [UNEP]). Here in Canada, the country’s commercial building sector accounts for 14 per cent of end-use energy consumption and 13 per cent of national carbon emissions. (For more information, see National Round Table on the Environment and the Economy’s (NRTEE’s) Geared for Change: Energy Efficiency in Canada’s Commercial Building Sector. Visit www.nrtee-trnee.com/eng/publications/commercial-buildings/exec-summ-commercial-buildings.php[1]. Visit www.nrtee-trnee.com/eng/publications/commercial-buildings/exec-summ-commercial-buildings.php[2]).

As awareness of energy-inefficient buildings increases, it is coupled with the emergence of new building and energy mandates. Therefore, it is little wonder that improving the building performance is a cornerstone of sweeping energy usage reform, sustainability efforts, and economic stimulus packages around the world.

The good news is commercial buildings show the highest retrofit potential of all building types. (Engineering News Record, 2009). Global electricity use in commercial buildings has almost tripled since 1980 and is projected to rise another 50 per cent by 2030. (See the U.S. Energy Information Administration’s (EIA’s) 2007 Annual Energy Outlook). Comprehensive retrofits can reduce a building’s annual energy consumption and costs by an average of 20 per cent. (Visit oee.nrcan.gc.ca/commercial/financial-assistance/existing/benefits.cfm[3]). As a result, retrofits can pay for themselves over time with paybacks from most measures ranging from a year to a decade. (Visit oee.nrcan.gc.ca/commercial/getting-started/payback.cfm[4]).

While commercial building owners are in a unique position to be leaders in sustainable design and improving building operations, conducting comprehensive performance analyses and implementing energy savings projects can seem daunting. For example, dated or non-existent building plans and incomplete energy consumption histories often make it difficult to predict future performance throughout the life of a proposed renovation project. As a result, it is imperative to ensure cost-effective methods of analyzing building performance are in place, and take both economic and environmental goals into consideration.

Benefits of using BIM to improve building performance
New methodologies like building information modelling (BIM) help make this once overwhelming prospect manageable. BIM is an integrated process for exploring a project’s key physical and functional characteristics digitally before it is built. The co-ordinated, consistent information used throughout the BIM process helps architects, engineers, contractors, and owners to see what their design will look like and how it will perform before construction. When applied to existing buildings, purpose-built BIM solutions can help capture the building geometry and characteristics needed to conduct various aspects of energy performance analysis.

Applying BIM to analyze existing commercial buildings also helps deliver numerous economic, environmental, and societal benefits that go far beyond complying with mandates. Extending BIM to analysis can help identify ways to:

• reduce resource consumption;
• increase onsite renewable opportunities;
• build consensus;
• review investment-grade audits;
• increase investor confidence;
• improve employee morale; and
• meet requirements for sustainable design and energy efficiency.

Reduce resource consumption
Building renovations and retrofits can leverage modern, efficient technology, systems, and controls to reduce energy, water, and material consumption. For example, BIM analysis tools can help analyze heating and cooling requirements, identify daylighting opportunities, and select major building equipment that may reduce energy use. BIM can also help analyze potable and non-potable supply options for occupants and building processes, evaluate stormwater systems, and simulate performance of collection systems, ponds, and culverts.

Identify onsite renewable opportunities
A co-ordinated, consistent model created through the BIM process can help design systems that minimize water use, protect existing wetlands, and focus on net-zero water consumption. With more sustainable designs, it is easier to encourage use of recycled water for irrigation of landscaping, minimize contaminants in wastewater, and investigate feasibility of capturing, recycling, and reusing water onsite. This minimizes the costs and impact on water and wastewater systems.

Boost stakeholder support
Using BIM analysis and visualization tools can greatly increase impact and clarity when presenting proposed modifications to key stakeholders. Allowing reviewers to perform virtual walk-throughs or to better see the modifications occurring over a timeline can help improve their understanding of the project and build consensus on how to address issues that arise. For example, a 3-D model site plan may quickly help identify whether a building renovation would affect access roads in a way that makes the proposed renovation impractical.

Making smart investments in improvements also increases potential investors’ confidence that funding will be used appropriately to support optimal performance of the building for a long and sustained life. BIM analysis tools can help owners more quickly identify where limited dollars should be spent, helping add integrity and legitimacy to the process.

Review investment grade audits
An energy services company (ESCO) can perform an in-depth analysis of a building or properties, design an energy-efficient solution, and install the required elements. Energy savings performance contracts (ESPCs) improve the energy efficiency of commercial buildings and commit to a defined payback period. However, it is still the building owner’s responsibility to perform due diligence on proposals to protect the constituent’s best interests.

BIM can be used to perform internal reviews of ESCO proposals to help evaluate key predictions and assumptions. For example, a virtual walk-through of the proposed renovations can be employed to increase confidence in predicted performance levels and reduce uncertainties associated with these long-term contracts.

Create better work environments
BIM can help identify opportunities for increasing the use of natural lighting or flow of fresh air within interior spaces. Modelling can visualize and simulate the impact of a lobby atrium or better ventilation on building performance. (At the same time, the designer should take into account the positive and intangible benefits these improvements can have on employee morale. For example, job satisfaction is commonly linked to increased productivity, higher retention rates, and fewer sick days.)

Case in point: York University
To illustrate the myriad uses of BIM, a case study can be helpful. Founded in March 1959, York University is the country’s third-largest university and a leading interdisciplinary teaching and research school. It has two campuses located in the heart of the Greater Toronto Area (GTA)—Keele (185 ha [457 acres]) and Glendon (34.4 ha [85 acres]), which together support 54,000 students with a staff and faculty nearing 10,000.

York has been at the forefront of sustainability when it comes to higher education institutions in Canada. In 2002, its Computer Science and Engineering Building won a Green Building of the Year Award from World Architecture magazine for being the first cold-weather green building for a Canadian university. Still, there was room to improve the integration process of design, construction, and post-construction in terms of facility management.

In the case of the Computer Science and Engineering Building, the architects and engineers who once worked on the award-winning project were long gone years later. Since the facility was developed using such advanced technology for the time, there was no BIM model to help make possible an ongoing lifecycle understanding.

Patrick Saavedra, a trained architect and urban planner, came on board as York’s manager of planning and architectural design in 2009. He quickly noticed some gaps in integration between the various operation and infrastructure departments at the university.

“Having come from a large fully integrated and multi-disciplinary firm where sustainability was key to everything, I knew the importance of ensuring proper integration of all disciplines from the inception of an idea,” he says. “I started to gather our team to discuss how we could manage our design process in a more integrated and holistic way, and BIM was the solution.”

One of the first ways the team employed information modelling was to construct some initial visualizations for smaller renovation projects. Instead of presenting typical floor plans, construction prints, and a materials board to depict design intent (which could often be confusing for clients to decipher), the team began using BIM.

“We started by creating a BIM model of a partial floor we were going to renovate, and did some initial investigation through the BIM process that we could use to extract some general data, such as views and layouts,” says Saavedra. “We found many of our clients around the university were quite receptive to the three-dimensional representation of the work we do.”

The BIM process enabled clients to ask more in-depth questions about projects (e.g. What would it look like with different materials or colours in a space? Can the lighting be improved?). The models could be quickly manipulated to yield visual results.

With the positive client and user feedback, the team at York decided to explore something much bigger when tasked with a complicated infrastructure project at the heart and nucleus of the university. The 46,450-m² (500,000-sf) project encompassed a 1968 facility housing three buildings—a lecture hall, the main library, and the main administrative building—sitting atop a raised concrete podium. Many needs had to be considered from those vying for a particular space with particular demands, including those of student services, the library, food services, and academic uses.

“We quickly realized we needed to overlay the needs of many stakeholders and look at the implications on the overall complex, because everything has a ripple effect,” says Saavedra. “So we decided to undertake an integrated study that looks at sustainability, architecture, urban design, landscape design, interior design, micro climate, operations, maintenance, and energy performance.”

Using a BIM process, the team is now testing numerous scenarios and design interventions, such as how replacing windows would impact energy performance (and therefore decrease utility costs), or how a green roof could mitigate the heat island effect on the podium.

“We also discovered through the BIM model that the micro-climate effect on the podium had a direct impact on the existing vegetation to the extent it was killing the trees,” explains Saavedra. “We were able to test different scenarios to correct that, while addressing other issues such as solar implications on the surface of the buildings.”

The study, which is still underway, is likely the first of its kind in an Ontario university to use a fully integrated design process using a BIM model. It will allow consultants and university administrators to make future planning decisions on building energy performance by changing things like roofs and windows. This practice will also provide the university the tools to discover and mitigate maintenance and operation issues that can be used by the different disciplines at the university, from the Department of Energy Management to the custodial department.

The planning and architectural design team is also hoping to leverage this study to do more large-scale integrated and sustainable projects in the future, using BIM for the university.

“Being sustainable for us means creating spaces and facilities that are flexible, so we can keep up with the changing pedagogical needs of the university as it progresses,” says Saavedra. “By being able to reuse spaces and use them efficiently, we’ll reduce our energy consumption significantly. We’ll also be able to reduce repetition and the need to create new buildings by optimizing use of existing space, classrooms, and other critical space at the university, thereby greatly reducing our carbon footprint.”

Best practices to BIM implementation
Getting started with BIM does not have to be difficult. From an owner perspective, there are numerous best practices to follow when moving from a traditional project delivery to requiring consultants use BIM.

Progressive owners should mandate BIM and make it a condition of contract. The benefits of BIM are proven, and it is now up to the Canadian architectural/engineering/construction (AEC) industry to take the lead and fully embrace and implement this next-generation methodology. By this same token, it is important to have the best consultants on the job. Firms who choose not to embrace BIM are at risk of being left behind in Canada’s competitive marketplace.

New BIM language should be included within Requests for Proposals (RFPs); the asking should be clear and detailed to avoid confusion and misinterpretation of needs. The pre-qualified consulting team, and its BIM process, must also be validated. It is important to differentiate between a consultant’s proven abilities to deliver information modelling services from blatant ‘BIMwash.’

Multi-party or integrated project delivery (IPD) contracts should be incorporated. These terms refer to a contractual model where all parties involved are in a single contract. The contracting parties share joint responsibility for both the definition of the project and the management of the process. The owner is actively involved on this team and has ultimate veto power over decisions in the case
of disagreements.

Once a team is in place, BIM can be used to help improve building energy efficiency and performance by following five basic steps.

1. Collect basic building information—including wall, floor, roof, and ceiling dimensions—on each building within the portfolio.
2. Create basic models for each building in the portfolio. It is possible to generate a complete model—including floor plans, elevations, sections, and 3-D views—from the most basic building dimensions in just a few hours.
3. Analyze building models for environmental and economic performance. Facilitate smarter, more sustainable performance by analyzing and simulating a wide range of options. For example, in the area of optimizing solar effects, models and integrated analysis tools can be used to evaluate sun position, solar radiation, shading, and daylight alternatives.
4. Compare and then prioritize projects or investment alternatives based on conservation objectives, such as water or fossil fuel usage, or financial goals. For example, evaluate the economic and environmental return on upgrades to mechanical, electrical, and plumbing (MEP) systems.
5. Select and act on top priority projects.

Conclusion
Whether it is for one or multiple buildings in a portfolio, conducting performance modelling and analysis can generate significant benefits by providing clear, consistent, and evidence-based building analysis that sufficiently details predicted performance. Embracing BIM can help a team more accurately understand related issues over the project’s multiyear lifecycle, and facilitate true sustainable design for improved building performance.

Caesar Ruest is Autodesk’s building information modelling (BIM) solutions executive for architecture, engineering, and construction in Canada. He meets with building owners and property managers to discuss the advancements within capital project delivery trends as it relates to planning, visualization, and management of assets for their lifecycle. Ruest is a member of the Canada Green Building Council (CaGBC) and the Canada BIM Council. He can be contacted
at caesar.ruest@autodesk.com.

Source URL: https://www.constructioncanada.net/leveraging-bim-for-sustainable-design/

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