The average cost recouped has dropped by 3.8 percentage points just since last year, according to the just-released 25th edition of the annual report. Cost vs. Value compares construction costs for 35 popular remodeling projects against the share of those costs recovered at resale. It gives results for the nation, for nine regions of the country, and for 80 specific markets.

"The results confirm what we have been experiencing: The economy, and with it the remodeling market, is recovering more slowly than expected," Remodeling editor Sal Alfano wrote in his introduction to the report.

The cost-value ratio had been as high as the mid-80s as recently as 2006, but then it started dropping, mainly because estimated project costs rose sharply while estimates of a home's resale value remained fairly stable, Remodelilng reported. The ratio could have moved back up again this year, given the more than 10% drop in project costs, bringing them back to pre-2007 levels. "But resale value dropped even more--the 15.8% slide is the steepest decline in this 8-year period," the magazine said.

Replacement projects again performed better in resale value than other types of remodeling. Seven of the 10 top-ranked projects include exterior replacements of siding, windows and doors. "This is partly because they impact curb appeal and also because they are relatively low cost," Alfano said. The three remodeling projects with the highest return in 2011-12 were fiber cement siding replacement, entry door replacement, and an attic bedroom remodeling project. "Since it was added to the survey in 2005, fiber-cement siding replacement has been remarkably stable," Alfano noted. "It has ranked first every year among projects costing $5,000 or more, and this year showed the smallest cost increase (less than 1%) of any project."

Projects in the South yielded higher cost-value ratios than elsewhere, mainly because project costs were lower, while the Pacific also beat the national average because of strong resale values. Projects in the North Central states trailed the nation as a whole because project costs rose while home prices shrank.

How much money a homeowner can recoup varies markedly by project. For instance, the average cost of replacing a steel entry door runs about $1,238 nationwide, but doing that can improve a home's resale value by $903, the survey of remodelers and realtors found. That's a 73% percent return. In contrast, remodeling a home office carries an average project cost of $27,963 but an increased resale value of $11,983. That means the return is just 42.9 cents on the dollar.

Attic bedroom projects and replacing garage doors were the only two projects that saw their cost-value ratios rise this year, Remodeling noted.

Construction costs are provided by HomeTech Publishing, a remodeling estimating software company. Resale value data are aggregated from estimates provided by members of the National Association of Realtors through an e-mail survey broadcast by Realtor magazine.