Prefab 3D Modular Panels Built for Tough Houston Weather

Here’s a home designed for minimal maintenance and energy consumption in its harsh climate.

Houston residents endure some extreme weather. The city’s subtropical climate results in basically two seasons: rainy and dry. Rainfall averages about 50 inches per year, making it one of the nation’s wettest cities. 

A highly humid atmosphere generates more than 100 days per year of temperatures of 90 degrees or higher, placing Houston within the top 20 of hottest U.S. cities, according to the National Oceanic and Atmospheric Administration (NOAA). And, although hurricanes and tropical storms are rare, they are not uncommon. 

All of this means that any new homes must be designed to withstand very harsh conditions—which is why Everlasting Homes Building Group (EHBG) opted to use the innovative RSG 3D Structural Concrete Insulated Panel (SCIP) construction system when building the 4903 Braesvalley Drive project.  EHBG is the only Texas builder to use the SCIP technology, according to EHBG General Manager George Mock.

Project Stats

HOTY-2024-logoFName: 4903 Braesvalley Drive, Houston, Texas

Builder: George Mock, Everlasting Homes Building Group 

Architect/Designer/Developer: Franck Boursier, Everlasting Homes Building Group

Interior Designer: Madelyn Kilkenny, Madhaus Co.

Photographer: George Mock, Everlasting Homes Building Group

According to Mock, the SCIP system consists of high strength, load bearing, industrially prefabricated 3D modular panels covered with shotcrete, as well as with a layer of galvanized mesh on either side of an expanded polystyrene Styrofoam (EPS) core. 

These are welded together by galvanised steel diagonals which penetrate the core, resulting in a lightweight, three-dimensional truss system with a high inherent stiffness and great thermal properties. These panels are used for structural walls, intermediate floors and roofs.

4903 Final front 300

Houses Are Built to Last

Braesvalley— the Wildfire and Flood Ready category winner of Green Builder’s annual Green Home of the Year competition—contains 20,000 square feet of RSG-3D SCIP with built-in R-20 insulation, and 1.5-inch, 4,000 psi concrete sprayed on both sides of the RSG-3D panel. 

These, plus 1,500 tons of concrete and 15 tons of grade 60 steel rebar, make the house energy efficient and weather resistant. The 4,700-square-foot, five bedroom and five-bathroom home has a HERS Index of 42, which makes it competitively energy efficient for dwellings of its size. It’s also a Department of Energy (DOE) Zero Energy Ready Home (ZERH).

RSG-3D SCIP has a strong history behind it. The product is ICC evaluated and certified, Miami-Dade Notice of Acceptance (NOA) approved, exceeds CA Title 24 Energy Code, reduces British thermal units (BTUs) by 60 percent, and has had zero damage in 20 years in 20 countries, Mock adds.

Meanwhile, in the durability department, the completed, monolithic home can withstand 200-plus mph winds, would survive an earthquake measuring 9.0 on the Richter scale, has a 2-hour fire rating, and is mold, wood rot and termite resistant. 

Massive Rain, No Pain

The home’s crown jewel is its flood resistance. Houston’s location within a storm zone—and its mere 43-foot elevation above sea level—results in flooding somewhere an average of four times every year, according to NOAA. On top of that, Houston is in a 100-year flood zone, which means there is a 1 percent chance annually of flooding, and that there will be at least one major flood during that period, according to the Federal Emergency Management Agency (FEMA). 

In recent times, Mother Nature hasn’t been kind: 17 inches of rain during the “Tax Day” flood of 2016; 61 inches from Hurricane Harvey in 2017; 30 inches from Tropical Storm Imelda in 2019; 15 inches from Tropical Storm Beta in 2020. 

Residents kept those figures in mind as they designed or rebuilt homes. But EHBG takes a different approach.

“Others in this neighborhood jacked their existing houses up 3.5 feet,” Mock notes. “If they built new, they raised their lot with 3.5 feet of structural fill, then built on top of that. We designed a 9-foot-high bottom floor that could flood and be repurposed.”

At Braesvalley, the bottom floor is basically non-living space—i.e., the garage. There are six floor drains connected to the city storm drain system; another 11 flood vents are in the walls and open automatically from water pressure. “After any flooding event, simply power wash your concrete walls and floor down the six floor drains and you are back in business,” Mock says. “No mold, no sheetrock, no big deal!”

Additional benefits include reduced sound transfer and an anti-allergenic environment, which helps provide healthy, comfortable living and working; better-regulated and reduced temperature swings due to the home’s concrete thermal mass; and an extremely low life-cycle cost due to reduced operating cost of energy, insurance, and maintenance. “Operational savings can easily reach 50 percent of the original investment in 30 years,” Mock notes. “[Add in] solar, and homes can contribute energy sales to produce positive cash flow.” 

4903 entry

Solid wood core doors, 7.5-inch-wide engineered wood flooring, and water-based paints reduce both short- and long-term offgassing.

4903 living

A 48-volt whole house, energy-saving LED lighting system runs on one 20-amp breaker and a battery backup.

4903 bath

Durable quartz countertops and flooring are easy to clean without harsh and toxic cleaners.

Key Components

Appliances: Miele (refrigerator, freezer, coffee maker, speed oven, dishwasher); Bertazonni (range and hood)

Building Envelope: RSG 3D SCIP structure (stucco and brick siding, plus wood-looking siding that is concrete)

Cabinets, Shelves, Millwork: Custom made (mix of paint grade and European style)

Caulks and Sealants: MasterSeal NP1 (polyurethane sealant)

Countertops: Quartz

Decks: RSG 3D/concrete

Doors and Hardware: Solid wood core doors (Kwikset brand)

Electrical: Standard 200-amp service with low voltage lighting system 

Exterior Finishes: Stucco/concrete, brick, simulated wood

Fire Protection: Smoke detectors and alarm

Flooring: 7.5-inch-wide engineered wood floor

Garage Doors: 16-foot-by-8-foot flush design, black with windows

Home Controls: Control 4

HVAC/Ducts: Ductless and ducted, all in conditioned space by structural design; Toshiba Carrier VRF system, 35-40 percent smaller due to tightness of the shell building and the energy efficiency of the R-20 insulation in the walls, floors and roof.

Insulation: Built-in SCIP panel (5-foot EPS - R=20)

Landscaping: Low water volume plants and grass

Lighting: 48-volt whole house LED lighting system on one 20-amp breaker, battery backup

Paints and Stains: Water-based paints by Kelly Moore

Plumbing/Plumbing Fixtures: Grohe

Renewable Energy Systems (solar, wind, etc.): House is solar ready with charger in garage, pipe from roof area to garage. HERS rating is 42 and certified to Zero Energy Ready Home (ZERH) by HERS Checker.

Roof: Concrete plus acrylic membrane

Ventilation: Whole home with Toshiba Carrier VRF system

Water Heating: Navien gas tankless water heater

Windows, Skylights, Patio Doors: Andersen 100 Series

Other: House is elevator ready, emergency generator ready. The Bottom floor is designed with six drains in the floor connected to the storm drain system. Flood gates open automatically if pressure builds inside. All electrical items are at plus 6 feet. Since the floor and walls are concrete, after flooding simply power wash walls and floor down drains.