Oops, No Ventilation

November 22nd, 2015

Peeling paint in only some areas of this exterior suggests vapor was gradually making its way through from the inside, loosening the bond between the paint and the wall. Behind the peeling areas you’re likely to find a bathroom, kitchen, or other humid area without a good vent. If this were new, tightly-sealed construction, but still […]

Catching Rays

November 1st, 2015

The solar energy that today lands wasted on thousands of acres of deteriorating San Francisco roof membranes will in the future be treated as a hotly contested resource. Rooftops will have to be thoughtfully partitioned, with sunlight allocated in proper proportion to roof gardens, interior daylighting (skylights), photovoltaics, and solar hot water (though increasingly efficient PV panels are […]

Oops — No Wind

January 21st, 2013

If we learn from our mistakes, students at Sanchez School will certainly benefit from the placement of this fence-top wind turbine.  As anyone walking by could tell you, the generator would do better on top of this 40-foot edifice than at the sidewalk. But would that be enough?  Industry rule of thumb suggests placing turbines […]

Building Science for Owners

January 4th, 2013

For a basic understanding of building science, here’s a powerpoint presentation from EnergyStar. Click on “Crash Course in Building Science” to download it. http://www.energystar.gov/index.cfm?c=bldrs_lenders_raters.ResESMktgSalesPresentation

Oops — Overwatering

October 25th, 2012

The watering system on the Dolores Street median looks grossly inefficient, but is actually par for the course. The EPA cites studies that show up to 50% of the 7-billion gallons of water a day used for residential landscape irrigation is wasted — due to overwatering, evaporation, or system over-design.

Oops – No Photosensor

September 17th, 2012

Well, at least they put in compact fluorescents. Now their bill for this pair of lights is a quarter of what it was. Obviously a photosensor would cut that down to an eighth or so. Say the original pair of 75w incandescents cost 150w x 24 hours x 365 days = 1314 kwh, x .15 […]

Tech Note: Radiant Barriers

March 5th, 2010

I’m always looking for “no-brainers” in construction — things to do that just make too much sense not to do. Here’s my experience with radiant barrier: Radiant barrier is a heavy-duty aluminum foil that reflects 97% of the infra-red spectrum. It’s available on the underside of plywood roof sheathing for new construction, or in rolls […]

Tech Note: Light Shelves

December 12th, 2009

A surprisingly effective way to draw light into a room is by use of a light shelf. These horizontal reflectors are mounted either inside, outside, or on both sides of a southerly-facing window. Sunlight bounces off the surface and onto the ceiling within.  Any bright surface will diffuse daylight effectively. In my office though, I […]