You can get quick results in your house history search from HPO’s HistoryQuest website, including who designed and built your house and when.  www.planning.dc.gov/node/1203082.  Select “square” from the dropdown menu and type in your square, e.g., “0788.”  (It may load slowly.)  If you are unsure of your square number, you can find it in www.taxpayerservicecenter.com.