The "Safe Haven" Home
Another style of concrete home construction was completed recently in Wind Lake, Wisconsin utilizing a poured wall forming system manufactured by Wall-Ties & Forms — a well-known supplier of poured walls systems located in Shawnee, Kansas. Walls Are Us, a southeastern Wisconsin poured wall contractor, was the subcontractor and has the rights to the building system in this area.
The poured wall building system has gone ‘above-grade’ in a big way with the Safe Haven home. It differs from other concrete home building systems in that the floor and ceiling is concrete — which forms a monolithic, thermal mass poured concrete "envelope." Concrete is poured in the wall and deck forms, and once the concrete sets up and cures sufficiently for the forms to be removed, work can begin on the ceiling, or the second level in a two-story structure. Walls, ceilings and stairs are placed monolithically. The roof is constructed with conventionally framed lumber or trusses. This allows for architectural flexibility in roof design while keeping the wood used for the roof framing outside to the home’s fire-resistant thermal concrete envelope.
Once cast, the exterior walls can be covered in a wide variety of materials from stucco to siding to brick or stone. Inside, because the finished interior concrete walls and ceilings are so flat and smooth, drywall is not needed. Walls and ceiling are plastered, including built-in crown moldings. Distinctive floor coverings that include carpeting, tile, hardwoods, and laminates, along with other extra touches add warmth and personality that usually surprises homebuyers when told they are looking at a home that is constructed with steel-reinforced concrete.
The concrete ‘envelope’ construction technique is relatively new, but promises to have its supporters because of the ultimate in thermal efficiency it provides and the rock solid security and protection it offers. The thermal mass concept is quite basic, and is similar to the adobe construction popular in the western U.S. Simply put, the concrete structure stores heat or cooling to be released or given back into the room when temperatures change. This process is supplemented with traditional HVAC systems, but concrete produces much more moderate temperature swings making a concrete home the ultimate in comfort.
From a structural strength and safety aspect, concrete has no equal. In independent testing, steel-reinforced concrete substantially outperformed typical wood walls for reducing flying debris and withstanding collapse and structural damage. In firewall tests, concrete has proven itself as one of the most fire-and heat-resistant construction materials available. And unlike wood, concrete is not susceptible to rotting or damage by insects like termites.
(For directions to the Wind Lake model and more information about the wide choices of architectural styles, one- or two-story homes in single or multi-family units available, contact Walls Are Us at 262-895-6847.)
Competitive Cost
In talking with contractors, suppliers and others involved in above grade concrete homes, when asked about the cost of this building system, the word is usually the same — "the price is fairly competitive with traditional wood building systems if you consider all the factors." We suspect that in reality, the initial cost of a typical concrete home will probably be in the 10%+ range, over wood construction.
You do have to open your thinking to a different way to build, and incorporate the savings from other areas like insulation, potential price swings in lumber, reduced sizing of HVAC systems and others. There is a ‘learning curve’ associated with concrete homes as with any other new construction technique. But, for those homebuyers looking for that special home, and who will appreciate the added benefits, a concrete home can be a powerful marketing advantage.
From the homeowners’ perspective, Safe Haven states that they will achieve a payback of the extra cost of their home over a traditional wood structure in energy savings, lower insurance rates, not to mention the additional comfort and the peace of mind they will experience. And, for those interested in doing something to save our environment, concrete is one of the most environmentally friendly and ‘green’ building materials available.
Foundations Choices
No discussion of concrete construction would be complete with addressing foundation choices. However, if ICFs and poured walls are making their way above grade, you can assume they are making huge strides below grade for foundations as well. Amerifax Data has tracked foundation preference information in Wisconsin, by county, since 1989. For the year 2000 in the twelve county area of southeastern Wisconsin, out of 6,262 new home starts, 4,548 — or — 72.6% chose solid concrete foundation walls; 1,545 — or — 24.7% chose block foundations; and 169 — or — 2.7% chose "other" foundation systems.
This is a dramatic swing from 1989 when in the same 12 counties, out of 4,508 new home starts, only 1,451 — or — 32% chose solid concrete foundation walls. We use this region of the state because it has traditionally lagged behind other areas for solid concrete foundations. We understand from our sources, that statewide and nationally the penetration of poured foundation walls is about 72%+, so it appears that the southeastern part of Wisconsin is catching up.
One other foundation system — the Superior Wall precast panels — which received some attention in the past seems to have disappeared from the Wisconsin market. Skotzke Construction of Greenville who provided this product shut their doors recently and left a trail of creditors behind, including this publication. Given the strength (no pun intended) of the marketplace the last few years, you have to question how any company could suffer financial difficulties in this business climate. We’ve been unable to determine what recourse or warranty protection remains for those builders who did use this system.
The Perfect Combination
Concrete homes provide unequalled airtight construction and every manufacturer or supplier usually requires a whole house ventilation system to provide the necessary fresh air exchange. With almost no air infiltration or exfiltration, this can be a problem in concrete homes without adequate ventilation. However, with appropriate HVAC systems, a concrete home can provide the most comfortable indoor air environment available from any type of construction today.
Hydronic radiant floor heating and concrete is a perfect partnership. Radiant heating provides the ultimate in air quality system — there is no dust or allergens flying around like you get from a force air heating system. Conventional heating systems also address the heat loss of the structure - whereas radiant floor heat addresses the heat loss of the human body. Radiant heat warms objects, not just the air. Radiant heat also takes advantage of concrete’s thermal mass — which absorbs and stores the heat, and then conducts it to the feet and to objects in the room. It can also be easily ‘zoned’ to place the heat exactly where it is wanted and needed. It has proven to be one of the most energy efficient and comfortable heating systems in use today. Cooling can be accomplished using a high velocity, small duct cooling system that has gained acceptance and popularity with homeowners for its comfort and efficiency.
Summary
While we don’t claim that 25% or even 10% of new homes built this coming year will be concrete homes, however, it is fair to say that they are finding a market from homebuyers who want the strength, durability and other benefits they offer. You’ll see more models being built in the near future, and you may even find one of your colleagues talking about how easy it is was to tote polystyrene around the jobsite rather than dimensional lumber boards!
And, if we continue to face material shortages, lumber price fluctuations, skyrocketing energy costs, and a continuing squeezing of our natural resources — there just might be a marketing advantage for discerning builders to promote concrete construction as a solution and the ultimate in energy and environment-conscious building.
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