Here are some national averages, including Arlington County, Virginia, for the value of popular remodeling projects:

• Minor kitchen remodel: 81 percent
• Bathroom addition using existing space: 72 percent
• Family room addition: 71 percent
• Master suite: 68 percent
• Two-story addition: 62 percent
• Deck addition: 54 percent

If you have seen this study before and think these numbers are lower than you remember, you are correct. Previously the study's methodology wasn't very scientific. It focused on the opinions of real estate professionals in 60 housing markets around the country - some of whom were in the business of selling homes for rehabilitation. Last year, in response to criticism, the Realtors added appraisers to the group of estimators. While this presumably improved the quality of the estimates, it also lowered the return-on-investment values since appraisers tend by their job description to be conservative.

So while the numbers may not look quite so promising as they have previously, the news may actually be better for homeowners since it is probably closer to the truth.