Managing commercial properties on Capitol Hill requires an understanding of rules and regulations designed to help preserve and protect the historic neighborhood’s architectural and residential character. We recently shepherded a window repair and replacement project and learned a lot about window do’s and don’ts in Capitol Hill from the Historic Preservation Office (HPO). HPO is part of the Office of Planning and serves as the staff to the Historic Preservation Review Board and Mayor’s Agent for historic preservation. The Capitol Hill Restoration Society(CHRS) is also a great resource for First, determine if the windows actually need replacing. Repairing windows do not require a permit. Many existing windows can often be repaired, scraped of old paint, repainted and made more energy efficient with the installation of weather-stripping and/or insulated glazing at a fraction of the cost of installing replacement windows. HPO window guidelines state a building permit is required to do any window replacement if your building is located in the Capitol Hill Historic District. There are four basic steps for replacing windows on an historic building: 1) determining if the windows can be repaired rather than replaced, 2) identifying the appropriate replacement windows, as needed, for your building, 3) finding a company that manufactures and installs windows, and 4) getting a DC building permit, with approval from the HPO. Contact HPO before you buy any windows. It also is helpful to send photographs of the building to an HPO staff member who can help you determine the appropriate windows for your style of building.