How Analyses Can Inform Building Design

Nov. 13, 2009
Building designs can be evaluated and refined to respond to their immediate climate and contextual surroundings  

Today’s technology allows architects to access previously unavailable quantitative information. Through analyses, building designs now can be evaluated and refined to better respond to their immediate climate and contextual surroundings. For analysis to be valuable, however, architects must keep several important considerations in mind.

1. Timing is Everything
Architects need access to the right information to make effective design decisions – and the earlier that data is available in the design process, the better. For example, performing a bioclimatic analysis can offer great insight into how local climate conditions affect human comfort and building performance. This data can influence decisions on the proper shape, orientation, massing, and volume of the building. So, the earlier you have the information, the better off you are.

The budget and ultimate project goals will determine the amount of analysis warranted or available. Project schedule is another important factor, so it’s critical that the schedule realistically accounts for the necessary time to perform an analysis. Remember: Analysis and design-strategy testing are nothing more than a feedback loop that allows you to compare how one strategy stacks up against another.

 Typically, there are three key times when design-based analysis is most beneficial:

  1. Pre-design
  2. Schematic design
  3. Design development

Analysis that’s performed after those phases is generally categorized as a “validation study,” since the majority of the design decisions have been finalized. Validation studies identify important issues, such as a building’s energy use exceeding code or baseline performance, but have limited ability to inform the design.

Timing a study can benefit a project. Imagine a team entering schematic design performing a high-level “shoebox” model on the building type’s potential energy use and end-use energy profiles. Early access to the data can give the designer a preliminary glimpse of where the majority of the energy needs are clustered. The team can then create an action plan that targets strategies to potentially reduce those loads. This could include testing various forms, orientations, glazing, wall types, and mechanical systems. During subsequent design phases, the level of data analyzed can be more precise and detailed for the potential energy-efficiency measures (EEM) that are studied.

2. There is No Silver Bullet
When it comes to analysis, there’s no single software that can do it all. In fact, the U.S. Department of Energy (DOE) lists 360 different options for software analysis. Bioclimatic, energy and daylight modeling, and computational fluid dynamics are each a suite of distinct tools. These various feedback mechanisms need to be used purposefully. Before you undertake any analysis, you should answer two critical questions:

  1. “Why are we using this tool?”
  2. “What are my expectations and how will we use the information to inform the design?”

The most appropriate tool may differ for envelope performance, glazing options, daylighting strategies, and selecting the best mechanical or renewable-energy system. 

While having access to analytical tools is a good thing, generating and disseminating the vast quantities of information can be a risky proposition. Successfully completing the tutorials does not mean that a person is qualified or has a meaningful understanding of the data. The truth is that a lot of users can’t readily identify errors in the output, and many of the analytic software programs can very easily provide erroneous results if one slight variable is entered incorrectly. This is where professional expertise pays off. In addition to being able to accurately enter and interpret the data, professional analysts know the inherent strengths and weaknesses of various analytic programs and tools.

3. It’s a Balancing Act
Of course, budget is the determining factor in almost all projects, and analyses might require more design work. Additional analysis can increase the initial design’s soft costs, but the intent should be focused on using any analysis to find options and solutions that provide more value to the owner (e.g. energy and maintenance cost savings) while enhancing the building’s performance. If all things go as planned, then the additional cost for analysis should be easily offset by the hard- and energy-cost savings. For example, early analysis can:

  • Highlight the viability of passive strategies, such as natural ventilation, that take advantage of wind direction or the angle of exterior shading to reduce solar gain.
  • Inform the design to allow sufficient interior daylighting, which lowers the need for artificial or ambient lighting, reducing the amount of necessary fixtures and energy consumption.
  • Examine sequencing to determine whether temperature setpoints could be 1 or 2 degrees cooler in summer and allow fans to move the air, leading to reduced mechanical loads.
  • Help determine the placement and cluster strategy of conifer trees for shading to lower thermal gain and block wind.

Whenever possible, the best course of action is to evaluate key design decisions not solely on first costs, but over the entire life-cycle of the building or system. Project teams can use this approach to determine which options are viable and bank the potential savings so that more efficient systems can be selected. The savings also can be held in reserve for additional contingency during the bidding process.

Thanks to advancements in analytic computational software, architects have a new world of information at their fingertips. With properly selected tools and correctly interpreted analytical findings, a new design process is taking shape – one where architects can better design holistic buildings that leverage performance, provide value to the owner, and achieve environmental stewardship.

Eric McDaniel, Associate AIA, LEED AP, is a senior technical consultant in the Advanced Climate Solutions team at Green Building Services Inc. The Advanced Climate Solutions team develops strategies and analyses that help projects and organizations address their energy use and carbon footprints. He can be reached at (866) 743-4277 or [email protected].

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