Housing Performance Evaluation

Housing Performance Evaluation is an objective indicator for houses. The system was born in 1999 with the enactment of the Housing Quality Assurance Act.

The Quality Assurance Act is, by its name, the "Act on the Promotion of Quality Assurance of Housing." So the focus is on how housing quality is secured. But housing had no "ruler" for measuring quality — so the Housing Performance Indication Standard was created as that ruler.

Whether you use this system is up to you, but if you do apply for evaluation, evaluating at least four categories — Structure, Deterioration, Maintenance, and Energy — is mandatory. The reason isn't clear...

So what value does Housing Performance Evaluation deliver?

• Objective evaluation from a third-party perspective
• The structure class can cut earthquake insurance premiums by up to 50%
• Can be used for Flat 35S (mortgage)

Roughly these three are the benefits the customer gets.

Is there no benefit for the builder? Builders often set their own internal standards — and these are often decided subjectively. By bringing in an objective gaze, quality can rise. I think most builders would get some new insights. Standards in structure and energy are changing fast in the world. Why not first try measuring your own house against society's ruler?

Having said that, the deterioration and maintenance criteria aren't substantial, so in practice the main parts are structure and energy. Doing more precise structure checks via allowable stress design. Evaluating energy performance with concrete numbers. These two are the important parts of housing performance evaluation.

What about cost? Are allowable stress design (structural drawings and calc book) and energy calculation (envelope calc and basis drawings) already included in the design fee? If they are, the cost of the performance evaluation application is at most about 200,000 yen. Earthquake insurance becomes cheaper, so you recover that quickly.

There's much to be said, but as a more engineering-leaning architect, I feel it's the bare minimum to have housing performance evaluation done as a matter of course these days.