Residential fire sprinklers in Petworth

Petworth is a neighborhood of 1920s brick rowhouses on deep lots, most of them two story with a porch out front and an alley in back. The houses were plumbed for one kitchen and one bathroom, and a large share of them still drink through the original half inch or three quarter inch service line. That single fact drives more of our Petworth work than any code section does. When an owner adds a pop up or carves a rental unit out of the basement, the sprinkler system that comes with the permit has to draw its water from somewhere, and a ninety year old half inch line usually cannot do it.

The projects themselves follow a pattern. A third floor pop up adds bedrooms and a roof deck. A basement gets dug out, a separate entrance goes in under the front porch, and the house becomes a two unit building. Two units stays in 13D territory, so the system is still a residential one, and the whole house is now in scope rather than only the new square footage. We see the same conversation on nearly every Petworth job: the owner budgeted for the sprinkler heads and the pipe and did not budget for the service upgrade that makes them work.

So our first step in Petworth is a records check, not a head layout. We pull what DC Water has on the service and confirm the size at the meter, run the hydraulic calculation against the actual line, and tell you before you sign anything whether the existing service will carry the demand. If it will not, the upsizing is a separate line on the quote, priced after we see the records, because the public side belongs to DC Water and their scope sets the cost. Owners who make that call early keep their permit schedule. Owners who find out at plan review redraw.

Why Petworth calls us

• We check the water service size with DC Water before we quote, because in Petworth the service is usually the real project.
• Pop ups and basement units are the two jobs we do most here, and we know how a two unit conversion changes the scope of the system.
• Plaster ceilings and party walls are normal for us; we route pipe through a 1920s rowhouse without opening every room.
• DOB filings ride with the quote, and the hydraulic calculation goes in the first permit set.

What it costs in Petworth

Same published table as everywhere we work. New construction, including new houses, townhouses, and new ADUs, runs $1.35 to $1.60 per sprinklered square foot. Retrofits in an existing house run $2 to $7 per sprinklered square foot, toward the top when ceilings are finished and the house is occupied, toward the bottom when the walls are already open. Water service upgrades are priced separately after we check the records with DC Water. The full breakdown is on the cost page, the unit count rules are on the ADU and conversion guide, the service line question is covered on the water service page, and existing systems are handled through inspection and repair.