La Solana

La Solana Town Homes, Hayward, CA

The La Solana project consisted of 58 two, three and four bedroom town homes targeted at first time low and moderate income buyers. The project was developed by Eden Housing a Hayward based housing oriented nonprofit organization. La Solana was one of several projects created as part of the U.S. Department of Housing and Urban Development's "Housing Cost Reduction Demonstration Program." The idea behind that program was to develop and field test ideas for reducing the cost of housing production in order to achieve affordability. The methods employed included streamlining the HUD approval process, use of HUD Section 236 financing, and other techniques. Great emphasis was also placed on energy efficiency in order to reduce the continuing cost of ownership.

The basic plans are simple and straightforward, and the finish materials are drawn from a builder's standard list of materials. However, as it turned out the pursuit of high energy efficiency resulted in construction that was very complex and costly. Each town home had both solar assisted water heating and space heating.

The solar assisted water heating was consistent with the state of the technology at the time of construction, roughly 1981. Each unit had a regular electric water heater, a solar storage tank, roof mounted collector panels, and the necessary electronic controls and valves to make the system work. The entire system followed standard designs and was built from off the shelf components.

The solar assisted space heating was entirely unique. Double glazed windows and patio doors, extra weather stripping, and careful sealing of the building envelope were part of the plan as well as foam insulation under the concrete slab first floor, and substantial insulation in the second floor attic space. Those things were well accepted and tested methods at the time. But, solar space heating generally involves providing a "storage mass" which is heated by the sun during daylight hours and which then gives off the stored heat during the evening and night hours when added heating is most often needed. The designers assumed, and I think correctly, that for many people an exposed concrete or tile first floor finish would not be acceptable. It was assumed that most buyers would want carpeting. But, carpeting would insulate the concrete slab from solar heating and render it useless as a "storage mass." The designers then turned to walls as a potential location for the "storage mass." By adding large quantities of sand to gypsum plaster and then applying a 2" thick layer to all of the walls separating the units sufficient mass was achieved. Unfortunately, the devil is often in the details, and the ultimate detailing of the technique proved very difficult for all of the contractors involved. However, in the end the desired result was achieved and the end product is shown in the snapshots below. These were taken at various stages of construction, through to the finished model.

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