Thacher Casa Dormitories


Ojai, California


The Thacher School


Heathcote & Associates Inc.

Project Size

8,557 SF

At 50 years old, Thacher’s original Casa Dorm building no longer met the needs of the school or its students. Because about 75% of the existing building was covered by mature, protected oak trees whose roots would be irreparably damaged by excavations for foundations of a new building, renovation of the existing dorm was the only option. By combining renovated portions of the original building and the careful addition of new construction, the architect was able to achieve a new design that met the school’s requirements, with a total of 31 individual student dorm rooms configured into two wings radiating from a central common area. Amenities include two common student bathrooms with showers and two separate laundry rooms.

All work was accomplished under the massive oak trees. To protect the trees, the team utilized the analysis prepared by the school’s arborist, who ascertained the extent of the drip line and evaluated the area outside the drip line. For the new addition, installation of a conventional foundation would sever a large, continuous portion of the roots of each tree. However, the arborist indicated that a foundation based on a grid of discrete caissons would have a negligible impact on these vulnerable roots. As a result, the project is built on 120 caissons, each drilled 17 feet deep through existing boulders, since another distinguishing feature of the site, besides the mature oaks, is exceptionally rocky terrain.

The building features standing seam roofs, Hardi-Panel siding and natural stone veneers made from the approximately 1,000 tons of large native rock uprooted during construction of this and other Thacher projects. Interiors incorporate high-grade finishes, timber beam construction, attractive wood paneling, radiant heat flooring and quality Loewen aluminum clad windows and doors. Neighboring faculty residences also received new underground utilities and completely upgraded infrastructure. All work was completed while school was in progress.