How to read a fire sprinkler bid for a DC rowhouse: the nine lines that have to be there

A sprinkler proposal for a rowhouse is usually one or two pages, and the total at the bottom is the least useful number on it. Two bids for the same house in Petworth can land thousands of dollars apart and both be honest, because one includes the ceiling patching and the DOB drawings and the other assumes someone else is doing them. Owners compare the totals, pick the lower one, and meet the difference as change orders in month two. This article is the checklist we would hand a friend before they signed anyone’s bid, including ours. Nine items, in the order they cause trouble.

1. The standard and the scope

The first line should say what the system is designed to and what it covers. For a rowhouse or a house with an English basement unit that is NFPA 13D, the residential standard. For a building with three or more units it is 13R, and the price and the paperwork both change, which the 13D versus 13R article sorts out. Then the coverage: every living space, or only the new addition, or only the basement unit. A bid that says “install fire sprinklers” with no standard and no square footage is not a bid, it is a placeholder. Ask for the sprinklered square footage in writing, because that is the number the published price table is built on and the number you will compare against.

2. Multipurpose or standalone

Most DC rowhouse retrofits use a multipurpose system, where the sprinkler pipe is part of the house plumbing, because it saves a separate riser and the backflow assembly that comes with it. Some situations call for a standalone system fed off its own tee at the meter. The bid should name which one, since it decides what a plumber can touch later and whether an annual backflow test follows the house forever. The multipurpose versus standalone article covers the tradeoffs. If the bid does not say, the contractor has not decided, and the price is soft.

3. Pipe material

CPVC, copper, or steel, and where each one goes. Almost every rowhouse retrofit in the District is CPVC in the heated envelope, with copper or steel where pipe runs through a cold rear addition or an unheated cellar, and the materials article explains why. A bid that is silent on material has left the contractor room to pick the cheapest option on the day, and on a house with a rear addition that has frozen before, the material is the whole question.

4. Who draws it and who calculates it

A residential sprinkler system in the District is permitted through DOB on drawings with a hydraulic calculation attached. Someone has to produce them. On a new house the architect’s engineer sometimes does; on a retrofit it is nearly always the sprinkler contractor, and it is a real cost. Look for a line that says the contractor prepares the sprinkler drawings and hydraulic calculation and submits them under the building permit. If the bid says “drawings by others,” you are paying for them somewhere else, and the permit steps article shows how they ride on the main permit.

5. Permit fee and inspections

DOB charges a fee for the sprinkler work and sends an inspector at least twice, once with the pipe exposed and once at the end. Both visits need the contractor there. The bid should state whether the permit fee is included and how many inspection visits are priced. On a rowhouse the fee itself is small next to the labor; the inspection visits are the cost, and a bid that prices one visit will bill the second.

6. The water service clause

This is the line that separates a careful bid from a hopeful one. The hydraulic calculation decides whether the existing service from the street can feed the system. Many older rowhouses in the District sit on a service that is too small, and the fix runs through DC Water on its own schedule, covered in the water service sizing article. A good bid says one of three things: the service has been checked and is adequate, the service upgrade is included at a stated price, or the service is excluded and here is what triggers it. A bid that does not mention the service at all is assuming it is fine, and that assumption is the most expensive one in this trade.

7. Ceilings, access, and who patches

Retrofit means opening ceilings. The bid should say how the pipe gets in, whether the contractor cuts and patches or only cuts, and whether patching means drywall to a paint ready finish or “rough patch by others.” On a plaster ceiling in a 1910 rowhouse the patching can be a meaningful share of the job, and this is the single largest reason two bids diverge. The occupied retrofit article walks through which rooms get opened. If the house is occupied during the work, expect the bid to sit toward the top of the range and say so.

8. Heads and finish

Concealed heads with cover plates cost more than exposed pendents and look like nothing on a finished ceiling. Sidewall heads avoid opening a ceiling at all in some rooms. The bid should say what type goes where, and it should list a higher temperature head at the kitchen. It should also name the exclusions the standard allows, such as small bathrooms and closets, so you are not paying for heads the rules do not require, and not surprised when a room has none.

9. Test, certificate, and what you get at the end

The job ends with a pressure test witnessed by the inspector and a signed material and test certificate handed to you. That certificate is the document your insurance carrier wants for the credit and the document a future buyer will ask for. It should be named in the bid as a deliverable, along with a valve location sheet and any spare heads left on site. If the bid ends at “final inspection,” ask for the paper.

Checking the total against the table

Once the nine items are accounted for, divide the total by the sprinklered square footage. Our published table puts new construction at $1.35 to $1.60 per sprinklered square foot and retrofit at $2 to $7, with occupied houses, plaster, and rear additions pushing toward the top. A 2,000 square foot new townhouse lands between $2,700 and $3,200 for the sprinkler line item. A retrofit bid under $2 per square foot has almost certainly excluded the patching or the drawings. One well above $7 needs a reason you can point to on the page: a water service upgrade folded in, a standalone system with a backflow assembly, or a house that stays occupied with plaster ceilings throughout. Those are legitimate reasons. “DC is expensive” is not one.

Two questions to ask the person who wrote it

First, who is licensed. The District licenses the sprinkler company, not the individual, and the company name on the bid should match the license, as the licensing article explains. Second, what happens if the hydraulic calculation comes back short. The answer tells you whether the contractor has done this on a DC rowhouse before. Anyone who says it never happens has not.