slab to grade foundation

[DC]

I have concerns with slab to grade foundations.  I am considering buying a house in the cascade Mts in southern OR constructed on slab to grade foundation. It was built in 2000 at an elevation of 4200 ft. Average year gets about 2 - 3 ft of snow or more. Its built in well drained soils and slab sides are insulated. To make it a family house I would have to add on at least a bedroom. How does resale of a slab foundation home compare with a home with standard foundation construction? Is it typically worth adding on to a slab home? I am also concerned with local climate. Winters are typically in the 20 to 30F with lots of snow. and finally plumbing issues. Just looking for anyone with experience with slab to grade in similar climate situation.

Thanks

[glenn-k]

I haven't done it up there but that is about all they build around here - no problems to speak of building on either as long as sound building practices are adhered to.  Seems the insulated foundation would be a good thing there.  Also seems that in 6 years any problems should have surfaced.

[John Raabe]

A properly done slab foundation is not a liability and should last just as long as other foundation types so long as drainage is maintained and non-treated wood is at least 6" from the soil.