Going Solar Inside a DC Historic District

Solar is allowed

DC's Historic Preservation Office has said that thousands of buildings in the city's historic districts already have solar, and that panels being visible is not by itself grounds for refusal. The review looks at how the system affects the building and the block, not at whether solar belongs there at all.

That is a better starting point than many owners expect. The work is in choosing a layout that respects the building and documenting it clearly.

Who reviews what

Every solar install in the District needs a building permit and a Pepco interconnection agreement. Houses in historic districts add preservation review on top, through the Historic Preservation Office and, where needed, the Historic Preservation Review Board.

Georgetown is different: projects there go to the Old Georgetown Board rather than the HPRB, with its own schedule and expectations. We plan the timeline around whichever body applies.

Layouts that move fastest

On a flat roof, the guidance quoted in an HPRB staff report from Anacostia is that panels should sit where the street cannot see them. A low rack set back behind the front parapet usually achieves that, and it is the layout we propose first on most rowhouses.

Rear roof slopes, garages and additions are the next best places on pitched-roof houses, since they face away from the street.

When panels will be visible

Some houses have no hidden roof surface, or the only sunny surface faces the street. Visible arrays can still be approved under the city's sustainability guidance when they are designed with care.

• All-black panels with black frames read as part of the roof.
• Low, flush mounting keeps the profile close to the roof plane.
• Simple rectangular layouts look calmer than scattered panels.
• Conduit runs inside or along hidden faces, not across the facade.

Pitched-roof houses in historic districts

Not every historic house is a flat-roof rowhouse. Detached and semi-detached houses often have pitched roofs, sometimes slate or metal. The rear slope is the natural place for panels, since it usually faces away from the street. Dormers, chimneys and roof shape decide how much of it is usable.

Slate needs particular care. Mounts have to be flashed through the slate without cracking the surrounding pieces, and replacement slates have to match. That adds labor, and on an old slate roof it is worth asking a roofer about its remaining life before anything goes on it.

What goes in the review package

1. Roof plan showing the array, setbacks and equipment locations.
2. Elevation drawings or sightline sections showing what is visible from the street.
3. Photos of the house and the block from public viewpoints.
4. Equipment spec sheets for panels, racking and inverters.
5. The building permit application that goes with it.

A complete package reviewed in one pass saves weeks. Missing sightline information is the most common reason a submission comes back.

Why submissions come back

• No sightline drawings, so reviewers cannot tell what is visible.
• Panels placed close to the front edge of a flat roof.
• Conduit shown running down the street-facing facade.
• Equipment described vaguely, without spec sheets.
• Photos that do not show the house from public viewpoints.

Each of these is easy to fix before submission and slow to fix after.

Neighbors and the wider review

Projects that go to the full review board can draw comments from neighbors and from the local Advisory Neighborhood Commission. Designs that are hidden from the street rarely attract objections. For visible designs, talking to immediate neighbors early and showing them the drawings tends to make the review smoother.

Timing

Preservation review adds time to the permit stage, more for visible designs or Old Georgetown Board projects. The install itself takes no longer than anywhere else. We file the review with the permit so the two move together.

Sources

1. DC Office of Planning: Solar in historic districts FAQ
2. DC Office of Planning: HPRB staff report, Anacostia
3. City Renewables: DC solar permit guide
4. City Renewables: Solar panels on DC row houses

Figures are as published by the sources above in 2026 and can change. Call (202) 978-0232 to check how they apply to your address.