Basement walls likely are not the first thing that comes to homeowners’ minds when building a new home. But when it comes to building more energy-efficient houses, more builders are taking them into account.
A new law looking to boost energy efficiency in newly constructed homes has builders looking to an alternative method of building basements to reap energy savings – precast concrete wall systems.
David Van Baren, president of Great Lakes Superior Walls in Hamilton, Mich., which sells the systems to Indiana builders, says demand is increasing. Sales in the Midwest this year are up 45 percent over the same period in 2012, largely because of increases in Michigan, the company reports.
Instead of pouring concrete on site or using concrete blocks to build basement walls, the new system comes in already-formed panels set in place with a crane, Van Baren explains.
The concrete panels are about 1.5 inches thick, and the panels have a rigid foam insulation layer on the outside. The system has an R value – a measure of energy efficiency – of more than 12, which is about what is achieved in traditional basement walls after they’re insulated. But more insulation can be easily added to precast panels to bump up the efficiency to as much as R-26, he says.
The system gives a complete thermal (seal) to the outside, Van Baren says.
That helps builders meet the new Indiana Energy Efficiency Code that went into effect last year.
Matt Brown, director of research and development for Energy Diagnostics Inc., a Valparaiso company that does energy-efficiency testing for Fort Wayne-area homebuilders, says the code requires new homes to be about 30 percent more efficient than the old standards, which date to 1992.
It’s a huge jump, he says, adding it takes more than small steps such as caulking and sealing to meet the new code.
Bart Singer, 42, a construction and information technology specialist, recently had Sterling Contracting in Pierceton use precast concrete basement walls in building his home in Huntertown. It was the first time the system was used residentially in Allen County, he says.
We use them (similar panels) in commercial warehouse work, so I got to thinking Why can’t we take this to the residential level, he says. It became apparent that on R values it was a top-of-the-line product, and along with the strength and speed of construction, it was hands-down a winner.
Contractors were able to shave about three days off the basement wall process, he says, and with extra insulation, he got a basement insulated to around R-20.
These panels do cost more, but they save you in your schedule of building, and if you’re planning a finished basement, they’re pre-studded, and you can attach your drywall straight to the wall, Singer says, adding he also liked that the panels had spaces for installation pre-cut.
Taking all that into account, In my scenario, they were 15 percent cheaper, he says, adding he is now creating a basement guest suite with a bedroom and, eventually, a kitchen.
We’re currently heating a 5,600-square-foot home for about $250 a month, and that’s for an all-electric home with six residents, Singer says. The basement, he adds, is quite comfortable.
Van Baren points out that livable basement space is becoming a premium in today’s smaller-footprint homes. While precast walls aren’t waterproof, they are damp-proof because the concrete is about 40 percent denser than poured concrete and the system includes sealing and drainage provisions.
Dave Fuller, commissioner of the Allen County Building Department, says the precast system competes with another new-technology concrete wall system. It employs insulated forms left in place instead of being disassembled after the concrete is poured.
That system was used in a home outside Warsaw built in 2009 to demonstrate green and energy-efficient methods in conjunction with Kosciusko REMC electricity cooperative.
Insulated forms are getting fairly common, especially on higher-end houses, Fuller says, adding that they, too, also cost more than traditional basement walls.
Instead of contractors’ disassembling and reusing their concrete forms, Fuller says, the homeowners pay for them, because they’re left in place. Cuts also must be made for other installation of other components, adding a step to construction.
Fuller says precast systems have been used in commercial work but hardly at all in residential construction in Allen County. He says he suspects that may be because of unfamiliarity or lack of training among local builders.
But Brown says precast systems may come into their own because of energy expectations by regulators and the public.
They’re being used more often in other regions in Indiana, he says.
They’re gaining ground in high-performance builders’ homes, he says, referring to houses that meet or exceed the new standards for energy efficiency.
They’re not quite hitting mainstream for a product, he adds, but they’re a very sustainable product, and they’re getting more popular.