Down by the water
The clients, from Phoenix, had dreamed of a house on the water in Coronado, the “island” that lies across a graceful arc of bridge spanning San Diego Bay.
Surrounded on three sides by glimmering blue bays and the Pacific Ocean, the seductive 13.5-square-mile city of Coronado is connected to the mainland by only a narrow, silvery spit of sand. Real estate in this exclusive enclave sells for more per square foot than almost anywhere else in California, and rarely comes on the market. Newcomers hoping to get a foothold here will spend astronomical sums to buy any odd piece of property they can.
So when the clients got a chance at a piece of land with a to-die-for view of downtown San Diego, they snapped it up -- for around $2 million.
It had some drawbacks. It was small -- about 7,500 square feet. The previous owner had sold viewing rights to the two-story house behind, so they couldn’t build higher than 11 feet. At high tide the water on the bay lapped to within 65 feet of where they wanted to begin construction.
“When they first got it, I looked at it and thought, ‘What are you going to do, have galoshes in the front room?’ ” said Harry Jackman, of the Coronado-based Jackman Group, a planning, design and construction firm.
Architect Tom Vaughn had a better idea: Build down. “Basically, it’s free space,” Vaughn said. “You can have all the bulk and height you need.”
Two and a half years and 1,100 square yards of concrete later, the clients from Phoenix have an 8,500-square-foot house, with more than half of it underground, including a 2,500-square-foot garage and 2,500 square feet of living space, with elevator, sauna and media room.
“At the beginning, I was wondering if this was all even possible,” said the lady of the house, who declined to give her name. “That was before I became a believer.”
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The big squeeze
The concept of living underground in sunny Southern California may sound like bad science fiction or a throwback to the era of the bomb shelter, but it turns out to be an imaginative -- if expensive -- way to get around strict zoning ordinances and squeeze really big houses onto really small lots. In Coronado, where the floor-area ratio above ground is tightly controlled and houses can be no more than two stories above grade, contractors can build out to the property line below ground.
“You can go 40 stories below grade!” Vaughn said, as if he’s waiting for a client to ask him to.
The Phoenix couple’s house was not the first on Coronado to be built down. In the last 15 years, Ralph Brienza and his son David, owners of Coronado Construction Management Inc., have built about 12 underground structures -- mostly garages and storage spaces. The Jackman Group has built a total of seven houses underground in the last decade, and two more are in the works. And recently, Santee-based Fred C. Perry Construction undertook its first underground structure -- a $12-million, 8,400-square-foot home on the bay. Perry, too, said he has plans for several more.
The underground phenomenon isn’t new -- homes burrowed into hillside berms were popular in the energy-conscious 1970s, and commercial buildings have long been built down, to accommodate parking, utilities and even shopping malls. But building basements below the water level does seem to be unique to Coronado. Representatives from the research arm of the National Assn. of Home Builders and the Building and Industry Councils of Los Angeles and San Diego counties said they could not recall such underground living spaces being built anywhere else.
Donna Morafcik, communications director for the Building and Industry Assn. of San Diego, said La Jolla is comparable to Coronado in both income level and scarcity of land. “On a wide-scale basis, though, I haven’t seen the whole underground thing come into play regionally,” she said.
Building down solves some problems peculiar to Coronado but has peculiarities of its own. Jackman and Vaughn have hit the water table in five of the seven houses they’ve built so far. Brienza has hit water with all of the houses he’s built there.
Brienza said he built 500 houses in Denver that had to deal with artesian wells and spring water flooding into the foundations. He claims to have brought the concept of building underground to the Coronado Cays, where he began to build houses with basements within 15 feet of the sea walls. He said he has had no problems so far.
“My concept is that you have to build good bathtubs,” he said.
Sometimes, though, builders confront unexpected obstacles. Perry confessed he “lost a few nights sleep” on his first venture underground. “We had 14 pumps going during construction. And then you have to make sure that you’re not sucking moisture away from other houses and causing a sinkhole,” he said.
Perry said they were pumping 565,000 gallons of water a minute during construction. Builders then had to get a permit to dump the water back into San Diego Bay. To do that, they had to run tests with fish and a sea urchin. But it turned out that fresh water was flowing in as well, so they failed the test three times.”We had to hire a marine biologist,” he said. “Every week they had to come and sample the water. That alone cost over $100,000.”
Building down will probably remain an option available only to the very rich of Coronado. While Brienza said he can build underground for as little as $50,000, Vaughn said his underground structures have ranged from $250,000 to $1 million, depending on size and whether the builders hit water.
Perry, whose first underground structure cost his clients $500,000, said money is no object for most of the people he works with. And he predicts the trend will continue.
“There is no land there,” he said of Coronado. “You have to literally wait for someone to die or sell their house. People pay $2.4 million for a [waterfront] lot that is 108 by 90 feet. It’s a lot of money for a little dirt.... You have to utilize every square inch to justify paying that kind of money.”
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Keeping the water at bay
The Phoenix couple’s house is a low-lying, pale cream collage of stucco, shingle and Texas shellstone, surrounded by concrete walls topped with laminated glass to take in the view of the bay and the dramatic downtown San Diego skyline. The walls also serve as a seawall (even the gate has a watertight seal), built to keep out rising water. Cement sofas and chairs topped with blue-and-white striped cushions are built into the patio.
The upper floor is spacious and airy and gives no hint of what lies beneath. The beachfront expanse is almost all windows, and massive skylights let the sun in. But because the grade for the house was below the mean high tide line, the project turned out to be one of the most challenging the Jackman Group has faced.
The builders hit the water table 5 feet below where the first floor was supposed to be. It took 15 dewatering wells to lower the water level so they could work. They pumped out 415,000 gallons a month for the first four months.
The first concrete pour took 42 trucks, Jackman said. The floors underground are 18 inches thick and the walls a foot, as impenetrable as a medieval fortress. The sand of the site, layered with plastic and a few concrete slabs, was waterproofed before the concrete pour with Paraseal, a mixture of plastic and bentonite clay. Vaughn describes Paraseal as “self-healing,” meaning that the material expands when water hits it and fills the tear.
“If the wall springs a leak, you just inject the wall with this huge syringe,” explained Sheryll Jackman, a real estate agent and designer for Jackman Group. Her husband, Harry, said a few houses have experienced very minor leaks.
On the street side, a curve of driveway disappears under the house and opens into a garage as big as many L.A. mini-mall parking lots. To counter the claustrophobic feeling of being underground, Vaughn tries to build his ceilings high and introduce a source of natural light. In this house the ceilings are 8 1/2 feet -- slightly higher than in a typical house. (Some of his underground living spaces have ceilings as high as 10 feet.)
In the first of two bedrooms there is a window onto a tunnel to the sky, resembling the view from a rabbit warren. Equipped with a 15-foot ladder, the tunnel allows a wan shaft of natural light to enter the room, which instantly dispels the bomb-shelter feel of the space. There is also a bathroom, a sauna and a media room below ground, and an elevator.
Though they say they trust Jackman and Vaughn, the new homeowners are nevertheless decorating to suit the milieu. Above ground, the house is full of glass, stone and expensive tile. Underground, it will be spare and simple.
“It’s not like we put in priceless things, or $500-a-foot carpet,” the client explained. “We decorated with the possibility of water damage.”
