I have been thinking of this issue Bugs brought up as well. The topic is near and dear to me currently. I figured that maybe his valuations have something to do with the fact that stairs are required for access.
The house that I am about to get the final for is a “Raised Ranch” with a stepped crawlspace foundation. Being aware of the issues with accessibility, I have built a large deck that bridges to a large terrace on the hill behind. The terrace is on level and connected by flat work, to the parking areas which slope gently back to the front yard.(I don’t prefer an attached garage). This terrace is going to be 1000 square ft. of mixed styles of flat work, slate and intergral colored concrete.Generally it is what one would consider the social area of the back yard. This level accesses a door to the family room and one to the great room that is big enough for wheel chair access.
Having access to most of the services under the crawlspace is great.
I exceeded the subfloor minimums by using plywood approved for a 24″ spacing on 16″ and using oversized joists. I glued and screwed the plywood.Where there is tile I put the joist spans at half of max. by installing and intermediate foundation. We put in 1/2″ hardi-backer underlayment where 1/4″ is the norm and “thinset” it to the plywood before screwing. There should not be any deflection problems.
In no way is building this way to be considered labor or capital efficient,for site built. For the rugged setting, the elevation lift of the crawlspace and building with the contours of the land really helps the look of the house.
My experience in RE and construction gives me the opinion that the slight,or even sometimes moderate settling of a raised house, is considered insignificant compared to a slab that cracks moderately, which has at times practically rendered a house economically obsolete, or at least require a very expensive engineered repair. I have never seen a lender balk at a wavy old crawl space built floor, on an otherwise decent house. That is not to say it doesn’t happen.
