This 1950′s California Ranch was situated in the bayside hills of Burlingame overlooking the San Francisco Airport. Dilapidated and sorely in need of renovation it was being used as an income property for the previous 15 years. The homeowners decided to renovate with the intention of upgrading the living space while optimizing the views.
To meet local municipal planning requirements the demolition of the existing structure was performed by hand. All salvageable appliances, bathroom fixtures, and building materials were meticulously removed and recycled to reduce construction waste that would otherwise be sent to the local landfills.
As is quite common with older homes built before the evolution of seismic building codes the existing foundation had dropped up to two inches on the downhill side of the home and less but significant amounts throughout the midspan footings. The result was an uneven undulating floor structure. This had to be corrected before the additional floor area and walls could be erected. The systematic installation of engineered structural beams at numerous locations allowed the existing floor structure to be tied to these beams and leveled via the use of point load posts to new footings and foundation walls.
Endeavoring to create more usable living area approximately one hundred cubic yards of earth was removed from the hillside to allow for the installation of a new retaining wall. As you will see in the photographs below the footing for this wall was seven feet wide, sixteen inches thick and keyed five feet below grade. Once the footing was placed a ten inch thick concrete wall nine feet tall was formed, placed, and finished to create the enlarged kitchen, dining room, and exterior patio space. A perimeter drain system to alleviate hydrostatic pressure against the retaining wall was placed along with a waterproof membrane adjacent to all living space to stop moisture penetration from underground water. Once these systems were installed the additional space was back filled in 12″ lifts and compacted to 95%. Finally a four inch colored concrete slab was placed and the retaining wall was veneered with a masonry stone surface.
Before & After
Photograph One was the existing right rear elevation of the home. Photograph Two is the same elevation after the renovation. The far right wing encompasses the master bedroom suite. The building was extended four feet and the finished floor elevation dropped twelve inches for sight line considerations of the neighbors. Photograph Three and Four are the left rear elevation prior to and after renovation. Close examination will show that the installation of a new retaining wall, shown on Page 3, allowed the Kitchen and Dining Room to be enlarged. The retaining wall also captured an additional four hundred square feet of previously unusable area. As you can see there is now a large exterior patio off of the kitchen and master bedroom that overlooks the San Francisco Bay and San Francisco Airport.