For too long, concrete has been synonymous with boring. Living in a house or apartment made of concrete gave off the distinct feel of being incarcerated in one's own living room. The material is quite affordable, however, and when manufactured responsibly it can be eco-friendly as well. Using only Tridipanel structural concrete insulated panels, Robert Mechielsen of Studio RMA designed a breathtaking two-family dwelling on Hawaii's Big Island. Called Hi’ilani EcoHouse, the home is the first carbon-neutral concrete structure in the USA, and it's within eyeshot of an active volcano!
Hawaii is paradise, but building a home there takes an experienced hand and a strong working knowledge of its unique climate and geology. Overlooking the Pacific Ocean, the 4,000 sq. foot Hi’ilani EcoHouse gets a lot of warming sun in the day time, but ocean breezes cause the temperature to drop drastically at night. Achieving carbon-neutral status hinged on Mechielsen’s ability to trap and repurpose the cool air that occurs naturally after sunset. The unique nature of long-lasting SCIP panels made this possible.
Often made of recycled plastic or metal, SCIP foam contains 90 percent air, which accounts for its terrific insulating properties. SCIP panels have a similar strength to 8” solid concrete or concrete block structures, although they use 60% less cement.
“These panels have an insulating core of EPS foam with a structural wire-mesh space frame stitched through the foam,” explains a press release. “Once the panels are connected to form the shell of the house they are sprayed off with a concrete-plaster mix, similar to stucco, creating the structural strength and the finish of the exterior and interior walls. Its vast cantilevered overhangs are completely made with SCIP only with additional rebar.” Thus the house is virtually wood and metal-free.
This unique construction material means that the Hi’ilani EcoHouse’s cooling is accomplished entirely by storing night-time cool temperatures in the insulated concrete ceiling plates for next day use. Fans distribute the cool air, while a computer system opens and closes motorized glass louvers, further controlling the temperature in the house.
Staying naturally cool isn’t the only benefit of the Hi’ilani EcoHouse’s unique construction, however. Because the house is built from concrete, it’s virtually invisible to the ever-present termites that love to feast on wood structures. This means that no toxic pest-control treatments are necessary. If you’re not in love with the color grey, it’s easy to augment the SCIP panels with lime plasters and even soy based stains to create a rich color and texture palette. And remember that nearby active volcano? Well it turns out that SCIPs are incredibly stable, and quickly becoming a favorite among Caribbean home owners who often face hurricanes, or in this case, seismic activity.
Being carbon neutral requires more than just special concrete and eco-friendly paint, of course. The Hi’ilani EcoHouse’s wing-shaped structure cleverly hides powerful solar arrays. The wings also harvest the rainwater and act just like the foils of an airplane wing catching the trade-winds to cool the building.
The home has a host of interesting features including a 25,000 gallon water-holding tank that doubles as an outdoor stage, an in-house spa, a media room and a music recording facility. And don’t think the carbon-neutral aspect of the Hi`ilani EcoHouse is limited to the construction: Even the CO2 emitted to build the home, including flying crews in, will be off-set by the creation of a 3-acre native dense forest.