As Florida’s housing market continued its struggle early last year, custom builder Bobby Alvarez realized it was time to differentiate his company. Demand was rapidly shrinking for the multi-million-dollar, 40,000-square-foot mansions the 28-year veteran of the Tampa building industry is known for.

“With the huge houses, we didn’t feel like the market was going in that direction forever,” he says. “My partner and I and the people in our office wanted to move toward green building.”

To attract clients looking for high-performance smaller dwellings, he founded Alvarez New Concepts, a spinoff company to his custom building business. In December, he completed his first sustainable project, a 2,500-square-foot home in the city’s walkable Hyde Park historic district certified to NGBS-Gold and Florida Green Building Coalition-Platinum.

But in his quest to set his new company apart, Alvarez didn’t stop with sustainability. Knowing that his customers are concerned about coastal storm safety, he also designed the home to be ultra hurricane resistant under the Institute for Business & Home Safety’s Fortified for Safer Living (FSL) designation.

The program’s rigorous requirements go beyond state and local building codes to increase a home’s resistance to natural perils. For example, the Alvarez house had to be able to withstand 140-mph winds, 20 mph stronger than code requires.

Alvarez and engineer Paul Kidwell found that high-performance home building utilizes many of the same products, principles, and technologies that ultra-weatherproofing does. For example, FSL’s mandate for an ultra-strong outer envelope meant the house would be built to super-tight and energy-efficient standards, starting with its concrete foundation and walls.

The two-story concrete block walls were poured with 4,000-psi concrete and reinforced with steel every 2 feet, Alvarez says. PolyMaster R-501 foam was injected around the concrete block for an R-value of 4.6 per inch.

“The first thing we planned for was to start out with a very tightly sealed house,” Alvarez says. “The house has lots of layers of insulation.”

Walls were insulated to R-19 with ¾-inch Owens Corning Foamular 250 rigid foam, followed by M-Shield paperless reflective insulation from Fi-Foil applied on ¾-inch furring strips.

An acrylic sealer from Porter PPG was used to protect the exterior of the concrete block. Workers then applied James Hardie’s Hardiewrap weather barrier followed by pressure-treated 2x4s, required by the FSL program for extra strength. The exterior was finished with 5/8-inch-thick Artisan Lap siding, also from James Hardie.

No area of the home was left uninsulated, Alvarez says. The attic and the ceiling between the floors were sprayed with Icynene LD-R 50, a renewable water-blown foam insulation and air barrier made from castor oil. Hilti spray foam was used to fill gaps around pipes, vents, ducts, outlets, and windows.

For extreme water and wind protection under the high-wind-rated Galvalume roof, Alvarez and his crew relied on the Huber Zip structural panel sheathing system and a secondary water barrier, peel-and-stick Polystick TU Plus, a rubberized asphalt waterproofing membrane.

High design pressure- and impact-rated windows and doors from Pella meet FSL criteria to resist wind-driven rain and to protect against windborne debris. In addition, pre-engineered wood roof and floor trusses were designed, installed, and anchored to resist the higher-design wind speed.

Besides its super-sealed, ultra-insulated shell, the home also boasts an array of other green features, including a rainwater collection system; Energy Star-rated appliances; LED recessed lights; two tankless water heaters; a Rainbird Smart Control irrigation system; and eco-friendly floors, countertops, and cabinets.

Built as a concept home for about $700,000 and now occupied by Alvarez’s son, the project has generated new customers interested in both its sustainable and stormproof features, Alvarez says.

“They like everything about it, they can’t believe how many things we took into account when building it,” he comments. “They’re overwhelmed with all the details.”

Although the market in his area is still slow, Alvarez believes that clients who tour the home will remember his company when they’re ready to buy, and he says he plans to build more high-performance homes in the near future.

The 10-year-old FSL program has designated about 250 homes across the country for their strength against perils such as hurricanes, tornadoes, wildfires, hail, and earthquakes, says media relations manager Joe King. In some jurisdictions, including 18 coastal counties in North Carolina, owners of FSL homes can receive a discount on their insurance premiums.

Because a significant percentage of Americans live within 50 miles of a coast or within wildfire-prone areas, incorporating durable building techniques into green projects makes sense, King says.

“Resilient construction goes hand in hand with green construction,” he notes. “And one of our houses is going to last, because the owners are not going to have to replace it after a disaster when everyone else has to come back in and rebuild.”

Jennifer Goodman is Senior Editor, Online for EcoHome.