Thermal programming and profiling using BIM tools

Vikram Sami, ZGF Architects LLP

With the rising cost of energy and water, and increasing concern about carbon dioxide emissions from building operations, there is an increased demand for building designs that deliver high-performance solutions that are cost effective and strategically targeted. As always, the challenge is in getting the right information to the client and design teams in time for it to be useful. The challenge–especially with lab buildings– is that the standard generic benchmarks do not address specifics within the program.

This session will outline the process of using the program document inside a BIM model to create project specific energy goals and target strategies, compare it to benchmarks and help designers test out the viability of different solutions. In this project, the program is entered into the BIM model as a series of rooms with occupancy types and areas defined by single lines. At this point there is no architecture yet. The room data is exported into Microsoft XL, where it references a template file to pull in additional data. The template file contains custom values for each of the program types that we typically come across in our projects – whether it's a chemistry lab, vivarium, informatics lab, open office or any other space. Each space type has values for energy usage metrics like expected fresh air requirements, plug loads, and lighting power density. There are also fields for footcandle requirements, glare sensitivity and daylight priority – which help designers prioritize which spaces benefit more from access to windows. We normalize for climate zones by assuming an envelope heat gain allowance. The data gets pushed back into the BIM model to aggregate the information.

Once the data is pulled back into the BIM models, we create custom visualization templates for the program that colors rooms by the different fields – like daylight priority, or internal heat gain, or air change requirements. This allows designers to start to think about these aspects even before they start to draw. For instance, if a program has a high percentage of high daylight priority spaces, it might lead to a scheme that is more skin dominated. It also allows designers to explore where they place spaces within a floor plate relative to their function, and tells them if they are over or under their program square footage, while even predicting a baseline EUI with a breakdown of energy end use types. As the rooms get placed into actual architecture, the data that is now embedded as room data, follows the rooms, and the values get updated.

Using a project that had just come out of programming, we beta tested this process and found that it provided very useful with visual data that informed the design process.

Learning Objectives

• Identify how Building Information Models (BIM) can be used at the programming stage of the design process.
• Understand what energy profiling is and how it can help set design strategies and goals for a project.
• Evaluate daylight programming and how it can be used to optimize a building layout.

Biography:

Vikram Sami is a sustainable designer with over 14 years of experience. He specializes in energy use and environmental studies and works to integrate sustainable design components and to optimize building efficiencies. He conducts workshops and charrettes to solicit ideas from owners, users, and design team members, in addition to conducting sustainable building research. Vikram has conducted building performance analyses and continues to conduct ongoing green building research.

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