Tiny Houses

Several places I frequent online have recently linked to a news report about an Oregon plan for construction of tiny houses in back yards as an attempt to reduce homelessness. Travel trailers and so-called mobile homes have much lower construction costs; why is the cost so high for these small structures. The crowd at Peter Grant's blog, Bayou Renaissance Man have offered some trenchant comments on the apparent high cost, as have those in other fora.

Here's a quick list of some of key reasons for the high relative cost of tiny houses, from my own mind and culled from what I've read in comments and elsewhere.

1. Foundation costs - even a small slab foundation is likely to run about $8000. Admittedly, some tiny houses are constructed on trailer frames of some sort, but many are also built on permanent foundations, as I understand the ones in this case are.
2. Bathroom and kitchen - there's a certain minimal cost involved in purchasing and installing the required fixtures and appliances, and this cost only increases when smaller, less-common versions are used (supply and demand) instead of standard ones.
3. Code compliance - while a "mobile home" has to meet building codes, travel trailers and other RV's have looser standard.
4. Finish quality - many of the tiny houses are built with pricier materials and finishes than a regular-sized stick-built house, let alone a mobile home. That may not be an issue in this particular story.
5. Economies of scale - tiny house construction projects usually lack any economy of scale. They're typically built as one-offs or in very small volumes. Mobile homes are often built more like assembly-line work than normal houses, and even subdivisions of normal stick-built houses can have decent economies of scale with respect to materials ordering, labor, plan costs, etc.