I am considering constructing a small cottage in a high-desert area of north-central Arizona. I like what I'm reading on the web about concrete, for its environmental benefits, low health impacts (I have MCS, Multiple Chemical Sensitivities, and am especially reactive to petrochemical products that out gas over many years), fire and other hazard safety, longevity, and low maintenance requirements.
Question #1.I haven't yet found much info on relative expense for concrete construction. How do building costs compare with standard stick-built wood construction, straw bale, rammed earth?
#2.I love the old Southwestern adobe-and-plaster houses that have soft, rounded corners inside and out, free-form seating benches, fireplaces, niches, and so on. I assume this is possible with concrete and would love to have some information on this.
#3.Insulation: What insulating methods work well for a concrete residence and which ones do not? Any advice on insulating only the exterior wall vs. insulating the interior wall? (Here again I am concerned about my exposure to petrochemically based products.)
#4.How do I go about finding really knowledgeable, skilled, experienced contractors for this kind of work?
Thank you so much for any and all advice and guidance you can provide.
#1 - Relative expense. When building with concrete frame and blocks, the cost should be comparable to stick construction or a little higher because you do not have as many competing contractors. If you go for 100% poured-in-place concrete you will find the costs are higher. The other methods you mentioned are usually associated with self-builders and I don't have any realistic cost estimates.
#2 The soft rounded style is a function of the finishing process. It is usually achieved by the application of stucco. To achieve the same effect with cast-in-place concrete will be expensive because of the forms involved, and the extra labor. But, again, when using block in-fill with concrete frame you can achieve similar finishes if you hire good contractor...
#3 Concrete itself will provide pretty good insulation because of its mass. It is especially evident in the desert. One method involves using insulating boards as part of the formwork, and leaving it in place. In Europe they use special blocks made from lightweight concrete. We do not have similar products here.
#4 Finding a good contractor is always a challenge. Contact a few; ask for references for similar work, and actually go and talk to these people. See and touch their work. That is the only way. Of course you should also check with your state's contractor licensing board and the BBB.
Good luck.