As Superstorm Sandy has shown all too well, the forces of nature can at times be frightening, destructive and unstoppable. In the face of global warming and climate change, we will continue to witness sea level rise, more extreme storm and weather cycles and the uncertainties of beach erosion -- all of which stand to impact the safety of
The threat of hurricanes, tsunamis and other major storms pose a challenge for seaside residents on both coasts, from the Eastern seaboard to right here in San Diego. Fortunately, however, experienced architects know how to work both in defense against and in harmony with the ocean to create sturdy structures. Built to withstand occasional flooding and storm damage, these homes simultaneously embrace the beauty and aesthetic opportunity coastal locations have to offer.
Coastal defense: East versus West
In my college days I spent a lot of time on Cape Cod, which has beaches protected by dunes that are anchored with cord grass and other vegetation -- a shore condition found in many parts of the Eastern seaboard. In our classes we learned about protecting and anchoring the dunes, and the heroic measures of sand replenishment to protect the beaches. On the east coast, the shore is protected by the great width of the beach and dunes.
In southern California, we do not have the luxury of beach width, as buildings are frequently located on bluffs and in beach areas that were defined before shoreline erosion. It is not unusual for homes to be located on a beach that is already flooded at high tide, and therefore subject to erosion of the beach fronting the home and undermining of the beach sand.
California coastal architecture
When approaching the architecture and the structural design of a home fronting the ocean, we confront some conflicting issues. A home near the ocean is designed for openness: to provide intimate outdoor spaces as well as expanses of glass to frame the view while also affording protection from the high winds, flooding and wave conditions.
Add to this the matter of coastal access: in California, where the public access to the beach is protected, we must plan for views and the occasional route of access from the street to the beach. The resulting intrusion by the public is far less severe than the effects of a hurricane; but it nevertheless creates a route for wave entrance and erosion that can be exploited by a storm and the resulting waves.
When building at the oceanfront, fortification of the lower floors is the first step. When within a few feet of the high tide elevation, the lower floor should be reinforced concrete or masonry. Just as the lower floor of a home in the floodplain of a river can be designed for springtime flooding, so too can a beachfront home be designed to withstand occasional flooding without permanent structural damage.
Next, we must consider the foundation system. Since it is now expected that the beach fronting the lot is more likely to be undermined, we consider a foundation plan that will provide support in all conditions, and restrain the soil on the side away from the beach. This can provide an opportunity to build in additional strength at the foundation level, so that space can be preserved in the upper floors. The resulting high ceilings and dramatic overhangs take full advantage of the requirements of the site, and create a wonderful environment for the home.