Nabih Tahan's Grant Street Project in Berkeley

The Facts:
Location: Berkeley
Type: Retrofit
Phase of Completion:  Completed
Project Lead: Bau Technologies (
Relevant Websites, Links, & News:


Remodeling a leaky bungalow into a Passive House: Nabih Tahan returned from Europe to promote the Passive House concept. His first project was to remodel a 100 year old leaky bungalow into a modern, energy efficient Passive House.  The six fundamental steps in creating a Passive House are described on this page. For additional information on the Grant Street project, please click here:

Article in Home Energy Magazine 2008 (PDF)

1. Foundation - Insulation on all sides of the foundation is necessary to eliminate heat losses to the ground

2. Framing - Optimal Value Engineered (OVE) framing techniques reduce lumber while still maintaining the structural integrity of the building and optimizing the insulation system. A Passive house minimizes themal bridging.

3. Insulation - The insulation system must form a continuous layer from the foundation to the top of the building envelope, without gaps or variations in thickness.

4. Air-tightness - A specific layer must be designated as the layer to prevent air infiltration to guarantee all joints, intersections and penetrations must be sealed air-tight.

5. Ventilation and Heat Recovery - A heat recovery ventilator transfers “free” heat, generated from lighting and appliances, from stale out going air to fresh incoming air. 

6. Verify - A blower door test measures whether the proper airtightness was achieved. 

7. Reduced Energy Demand - A building envelope, (remove-consisting of the 6 steps mentioned above), designed and built according to the Passive House Standard results in an 80% reduction in heating demand. The additional energy requirement can be generated through conventional or alternative energy systems.

Additional Info:

Contact Nabih Tahan
email: or or

Contact Chris Polk for design build

and Passive House projects at

Bronwyn Barry,
Jul 24, 2011, 1:49 PM