Section 1: What is building performance analysis?


  1. Understand how building performance analysis works
  2. Learn how you can understand the performance of your building
  3. Learn how you can improve the performance of your building


Building performance analysis at the early design stage involves implementing an iterative process in which you continually assess how your building is performing, what is driving that performance, and what you can do to influence it.

The traditional energy modeling paradigm is misaligned with the design process, and incapable of delivering on the promise of great performance. This is largely because energy modeling tools were not intended to be architectural design tools. They are useful for designing mechanical systems and performing validation analysis on fully detailed models — and for these uses, the energy modeling paradigm will continue to be a necessary part of the overall design process.

But the energy modeling paradigm is too far removed from the creative, iterative, real-time nature of design. If we want a tool that can meaningfully inform design — that can have significant impact on energy consumption, operating cost, and the capital costs of the HVAC systems; that is useful from Schematic/Conceptual Design through Construction Documents, when architects are actually making design decisions — then the industry needs a new approach. It is a completely different way of thinking about performance. 

How does performance fit into the architectural process? 

We spent significant time talking with architects and building designers to understand their processes and workflows. We found that design moves incredibly quickly; that architects spend most of their time in their 3D modeling or BIM environment; and that their overhead of switching between applications is high.

In addition, we discovered that the performance-related questions architects ask during design are very different from the questions that energy modeling is instrumented to answer. Architects wanted to know:

  • What’s important? What elements of the design should they focus on? Where are the biggest opportunities to have an impact on performance? Is it a tighter envelope, preventing solar gains, or providing good daylight?
  • What are the constraints? Designers want to know the constraints and boundaries of the problem. If they know early on that south shading is critical, or that a 55% glazing ratio is ideal, or that a 50-to-60-foot floor plate provides a great balance of daylighting and energy performance, they can use these as meaningful constraints to inform the design.
  • Is it possible to do X? Can the design be naturally ventilated? Could passive solar address most of the heating needs? Could we meet all energy needs from on-site renewables?
  • How does my design compare? — to other design options, to typical buildings in my area, to an ASHRAE 90.1 baseline, to 2030 Challenge goals? When exploring the design space, comparisons are critical.

These are the questions that the new approach must answer.

A New Approach: Feedback, Not Analysis

The alternative to energy modeling is a real-time, multiple-options-at-a-time, results-first paradigm in which seamless performance feedback informs design decisions throughout the design process.

This form of building performance analysis aims to be part of the design process. Feedback can’t depend on a finished design — instead, the feedback needs to be continuous, helping designers explore the design space, understand their options, and make informed decisions.


If energy modeling is a slow, one-design-at-a-time, input-heavy approach, building performance is the opposite: a real-time, multiple-options, results-first paradigm. Each of these capabilities is critical for aligning performance feedback with the design process.

Real-time: Sefaira provides immediate feedback on energy, daylight, and other metrics, with a preference to delivering these in the architect’s native design environment. We want feedback to be always available to the designer — a fundamental departure from the idea of “analysis” as a separate, after-the-fact activity.

Multiple options: Sefaira is built on the idea of exploration — of testing out different design ideas, whether through real-time analysis within the 3D modeling environment, via comparison of options or iterations, or by quickly investigating the impact of many different design strategies. Exploration is key for answering design-oriented questions like “What’s important in my design?” and “Which option is best?”

Results-first: With only two inputs — space use and location — architects can start seeing feedback on design decisions. The feedback is designed to be actionable — helping designers understand how the building is operating and what they can do to improve. This allows designers to shape the design based upon results, rather than simply analyzing a design that’s already complete.

What’s revolutionary about this approach is that it makes achieving performance a creative endeavor — no different from meeting the constraints of program, context, and site that have inspired building designers for generations. By making performance accessible, it opens up a new design space, and empowers practitioners to address performance as a standard part of the design process. This is the future of performance: a seamless, essential part of design.


  • Other architects are already using building performance  to inform their every day design decisions
  • Building performance analysis in design and energy modeling are two very different things
  • Incorporating building performance analysis in design is a creative process that will further enhance your concept. 
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