A consumer going on Porch enters his or her's ZIP code and immediately gets a map of the area, dotted with the names of contractors, tradesmen, architects and design-build firms working in their neighborhood. In addition to the professionals, there are also little cameras, which when clicked show pictures of neighbors' renovations. Names and addresses are not included, but people can get a general idea of where they are.
"The only things that have really existed in the past are review sites. Some are paid, some are free, where consumers go in and they read third-party reviews. Sometimes they are real, sometimes they are not," said Ehrlichman.
Architect Bruce Wentworth is now pouring most of his marketing resources into social media. Listed on Porch and Houzz, the founder of Washington, D.C.-based Wentworth, a design-build firm, said social media validates his expertise and reputation.
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"In the long term it's excellent because people will really begin to see who are the better firms, who does the better design, who does the best construction, who is more trustworthy and reliable and has proper credentials," said Wentworth.
Karen Smith gutted her 1930s home to add space and modernize. She found her architect the old-fashioned way, by word of mouth from a trusted realtor, but social media sites came into play toward the end of the project.
"We started three to four years ago, a little before all of that stuff got really big. In the final stages, my husband discovered Houzz, and we certainly have looked on there a lot for more decorating ideas," said Smith.
Had she started the project today, Smith noted she would have used design websites more.
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"I definitely think it would be a complementary tool to word of mouth, and all those other ways you find people to do things for you," Smith added.
Confidence is key for homeowners, who readily admit that renovations are as emotional as they are costly. Porch's Ehrlichman said his site gives consumers confidence that the professionals they choose are trusted and competent. Wentworth said the sites help consumers avoid over-improving their homes, given the price point in their local neighborhood. Of course there are downsides.
"It's easier for your competition to find out what you're doing, and if there's a problem client, it can be a negative if it's not handled properly," added Wentworth.
—By CNBC's Diana Olick. Follow her on Twitter @Diana_Olick. CNBC Real Estate Producer Stephanie Dhue contributed to this report
Questions? Comments? facebook.com/DianaOlickCNBC