Passive House Accelerator—Design First, Performance Always – GreenBuildingAdvisor

By Michael Ingui | December 26, 2025

Most residential projects that outperform code have more than a simple product or detail to thank. Rather, they perform so well because many early decisions work together to simplify implementation downstream and ensure high performance.

Integrating Passive House strategies from the earliest phases of design, rather than attempting to tack performance measures onto an already-designed project, is key to ensuring success. Important operational and performance-related decisions should be made before finalizing assemblies and selecting mechanical systems. By the time a project reaches design development, many of the outcomes that matter the most are already constrained, from mechanical complexity to usable volume to long-term serviceability.

Let’s take a practical look at what needs to be resolved early, how experienced teams approach the challenge, and why those choices tend to make projects easier to build.

Obtain a rough load picture

Final numbers are not necessary at the early stages of a project, but design teams should ensure that the building they’re drawing can reasonably support the expected level of mechanical supply. Producing a rough energy model at the outset can be helpful to reduce mechanical systems.

At this stage, teams should be testing glazing ratios by orientation, reasonable ranges for wall and roof insulation, and volume-to-surface area relationships. This gives your design team an accurate sense of the basic parameters inside which they are designing.

Tessa Bradley of Artisan’s Group has described using early models specifically to identify which design moves will be expensive later, and which are cheap now. The goal isn’t necessarily precision at this stage, but to avoid false assumptions early in design.

At Ingui Architecture, our primary focus is retrofit projects. In these projects, modeling the existing house during the pre-design or schematic phase ensures that we fully understand how the existing house performs,…