Built-for-sale or “spec” homes have been particularly hard hit by the housing downturn, according to a new NAHB survey on the various components that go into the price of a typical single-family home.

Based on responses from 54 builders in 2009, “Breaking Down House Price and Construction Costs” found a relatively high proportion of custom homes — homes built on a lot owned by the customer, who hires a general contractor to perform the construction work — rather than spec homes.

The 2009 construction cost survey also found that the costs of construction accounted for nearly three-fifths of the final sales price of the average home, and the cost of the finished lot accounted for just over one-fifth.

The average size of the surveyed homes was just over 2,700 square feet, and the average lot size was one-half acre.

The average price of the new single-family homes in the 2009 construction cost survey was $377,624. The cost of the finished lot accounted for a little over one-fifth of that price, the cost of construction accounted for nearly three-fifths and the balance came from the costs of construction financing, selling the home and overhead and profit.

At 15.6%, framing and trusses accounted for the largest share of construction costs, followed by excavation, foundation and backfill work (7.1%). Siding, plumbing, drywall, cabinets and countertops, and tiles and carpet accounted for between 5% and 6% each.
NAHB’s research has identified framing/trusses and windows as the two components of a single-family home that have been on the decline fairly steadily since 1988. Siding and roofing shingles are two components that have been on the rise as a share of total construction costs.

The Builder Practices Survey suggests that the rising cost-share of siding may be the result of a shift toward more expensive materials. That survey indicates that, since 2002, brick has steadily increased its market share and replaced vinyl as the siding material most commonly used on single-family detached homes.

Profits amounted to 8.9% of the house price last year, the survey also found.

Click here to read the entire report.