How much (typical) will my home value increase by adding second floor space?A 16 x 21 ft room has two story open plan with windows both top&bottom. Want to install a floor between to create additional upstairs space where the bedrooms are located. Quotes to add floor range from 13-20K.May 14 2009 - Batavia00YesReport a ProblemProblemSelect oneOffensive contentIrrelevant contentSpam (pure self-promotion)OtherDetailsYour emailPlease enter a valid email address.Submit CancelContent flaggedWe will review this content. Thanks for helping make the site more useful to everyone. To learn more, read Zillow's Good Neighbor Policy.We're sorry. This service is temporarily unavailable. Please come back later and try again.