How long should houses last?

After an involuntary overdose of HGTV and the statistics on how square
footage of single family homes has increased over the past few
decades, I'm wondering if the time has come to start building
disposable homes -- built to last x years and then are easy to
demolish/recycle.

The problem isn't just size. According to the designers/decorators,
most people want open floor plans -- living rooms flowing into dining
rooms flowing into the kitchen, etc.

That often requires difficult and/or expensive remodeling, which
doesn't always meet expectations, of older homes. In many cases it
seems it would be faster and easier if they could dismantle the
standing structure and start from scratch.

The fact that plumbing/electrical/fire codes are always evolving only
contributes to the present problem and makes the idea of replacing
rather than revamping more desirable.

If this is a viable concept, what would be the ideal length of time a
single family house should be expected to last?


This might seem like a sociological problem rather than one of hard
science, but I'm asking it here because technology would play a vital
part -- developing materials and techniques which meet expectations as
regards withstanding the elements for specified years/decades but
which will easily fall to a demolition crew after that. 

Could such materials/techniques be realistically developed in the near
future?


SFnal aspect -- the city of the future might have even more pronounced
distinctions between neighborhoods depending on where they are in the
"new->still usable->should be replaced->new again" cycle. The ease of
demolition could shorten the cycle during prosperous times, but large
numbers of houses could literally fall in on themselves if a
depression/recession lasts too long.

Opening line/quote that comes to mind: "Last night's rain flattened
six homes on Maple Street."
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