Sprinklers in a DC historic district renovation: what preservation review does and does not touch

About one in five buildings in the District sits inside a historic district. Capitol Hill, Georgetown, Dupont Circle, Logan Circle, Mount Pleasant, LeDroit Park, Anacostia, and a few dozen more. Owners renovating in those neighborhoods hear that preservation review will slow everything down, and then hear that a sprinkler system is required for their basement unit, and assume the two are about to collide. Most of the time they do not. This article explains where the Historic Preservation Office actually looks on a sprinkler project, the three places a sprinkler job can cross into review, and how to plan the system so the original fabric of the house survives it.

What preservation review is for

The Historic Preservation Office, part of the Office of Planning, reviews permit applications for properties in a historic district or individually designated landmarks. Its standard is whether the work is compatible with the character of the district, and its attention is on what can be seen from public space: the front facade, the roofline, visible side walls, and in Georgetown, more or less everything, because the Old Georgetown Board under the Commission of Fine Arts reviews there as well.Interior work in a private rowhouse is, in nearly every case, outside that review. A sprinkler system is an interior system. That is the short version, and for most projects it is the whole answer.

Where a sprinkler project does meet review

There are three ways the sprinkler side of a renovation can end up on the preservation reviewer’s desk.

The water service. A sprinkler system that needs a bigger service line means an excavation from the main to the house, across the front yard or the areaway, and in a historic district that trench can run through an iron fence footing, a brick walk, or a set of stone steps that are part of the reviewed facade. The pipe itself is not the issue. Reinstating what was disturbed is. HPO wants the fence, walk, and steps back as they were, and a contractor who plans the route around them saves a comment. The service sizing article explains when an upgrade is likely; in a historic district it is worth settling before the preservation submission, not after.

Anything on the outside wall. Larger buildings on NFPA 13R usually carry a fire department connection and an exterior alarm bell or horn, and both tend to land on the street facade where preservation review sees them. A 13D house does not need either, which is one reason a two unit conversion is simpler than a three unit one in a district. Where an exterior device is required, the placement drawing goes in the set for review, and a side or rear location that meets the fire code will usually clear faster than a front one.

Interior features the district has designated. A handful of DC landmarks carry interior designation, where plaster ceilings, moldings, or a stair hall are themselves protected. In those buildings head placement and pipe routing are reviewed. This is rare for a private rowhouse and common for a converted church, school, or embassy, and the owner of one of those already knows it.

The permit sequence in a district

Preservation clearance is not a second permit. It is a review that runs on the same DOB application, and the building permit does not issue until HPO has signed. For work that is clearly compatible, staff clears it the same day in many cases and inside five business days for the harder ones. For work that raises a question, it goes to the Historic Preservation Review Board’s monthly agenda, normally the fourth Thursday, and HPO puts that path at 30 to 60 days from filing. The sprinkler drawings ride in the set either way, and the permit steps article covers what DOB itself wants from them. The practical rule is to keep the sprinkler off the HPRB agenda entirely by resolving the service line route and any exterior device before the first submission.

Keeping the house intact: the design choices that matter

Preservation review may not look at the ceilings, but the owner does, and a 1900 rowhouse with its original plaster, cornices, and medallions deserves a sprinkler design that treats them as fixed. These are the decisions that decide whether the system disappears or announces itself.

• Sidewall heads instead of pendents. A residential sidewall head sits high on a wall near the ceiling and throws across the room. In a room with an ornamental ceiling it means one small hole in a plain wall instead of a pipe run through the plaster. Most rowhouse rooms are narrow enough for a single sidewall to cover.
• Route through the closets and the stair. Rowhouses stack closets and bathrooms floor over floor, and a riser run up through that stack reaches every level with almost no visible pipe. The party wall side of the stair is the second best chase.
• Concealed heads where a ceiling has to take one. A concealed pendent with a flat cover plate reads as a small white disc. Plates come in colors and can be painted to match a tinted ceiling at the factory, which is the only painting a sprinkler head should ever get.
• Attic and top floor from above. On a house with attic access the top floor heads drop from above and the top floor ceilings stay untouched.
• Retrofit access from the floor above. Where a floor is being refinished anyway, feeding the ceiling below from above saves the plaster entirely.

None of this costs much more in pipe. It costs design time, which is why the sprinkler layout should be drawn from the architectural set with the preserved surfaces marked, and why we ask for a walk through before we draw anything in a district house.

What it costs, honestly

A historic district does not change the published rate. New construction work is $1.35 to $1.60 per sprinklered square foot and retrofit work runs $2 to $7, with an occupied plaster rowhouse toward the top of that band because of access and finishes, not because of the preservation designation. What a district can add is the reinstatement of a front yard after a service trench, which is masonry and ironwork rather than sprinkler work and is priced by whoever does it. The cost page has the worked examples.

Three things to do before the first HPO conversation

1. Confirm whether the project creates a second unit, which is what brings the sprinkler requirement with it under the conversion rules.
2. Get the water service checked so you know whether there is a trench in the front yard to draw.
3. Walk the house with the sprinkler designer and mark which ceilings and walls cannot take a pipe.