Renting a DC rowhouse by the room: where a group house turns into a rooming house, and where the sprinkler requirement comes from
Half the rowhouses around the universities and the hospital corridors are rented to groups. Most of them are ordinary single family rentals with four or five names on one lease, and the District treats them that way. A smaller number are rented room by room, with a lock on each door and a lease for each tenant, and those are a different thing in the zoning rules, the licensing rules, and the building code. The building code difference is the one owners find out about last, because it is the one that brings a sprinkler system. Here is the line between the two, which system each side of it gets, and what the retrofit costs against the published range.
A household versus a rooming house
The zoning rules define a household broadly enough to include a group of unrelated adults living together as a single housekeeping unit, up to a cap on how many. A house rented that way is one dwelling unit and nothing about its occupancy changes the code it was built under. A rooming house is a dwelling where rooms are rented separately and the occupants share kitchens and baths. The District licenses it under its own category with a basic business license and a certificate of occupancy, and the housing code inspects it on its own schedule. The arrangement, not the head count, is what moves a house across the line. Five friends on one lease is a household. Five strangers on five leases with five door locks is a rooming house, even in the same building.
Where the sprinkler requirement comes from
The residential code that governs a rowhouse covers one and two family dwellings and a narrow class of small lodging houses. The way the model code is written, an owner occupied lodging house with five or fewer guest rooms can stay under the residential code only when it has a sprinkler system installed to the residential sprinkler section, which in practice is a 13D system. Anything larger, or a rooming house the owner does not live in, falls out of the residential code and into the building code as a congregate residence, where sprinklers are required throughout any residential fire area. Up to a modest occupant count the building code still allows a 13D system for that use. Above it the building is read like a small apartment house and a 13R system applies. The 13D versus 13R article explains the difference between the two systems and why the 13R one costs more.
| Arrangement | What the District calls it | Sprinkler answer |
|---|---|---|
| Unrelated adults, one lease, within the household cap | Single family rental | None. Same house it always was. |
| Owner lives in, rents up to five rooms separately | Rooming house, residential code path | 13D system through the house, or it leaves the residential code. |
| Owner lives elsewhere, rents rooms separately, small occupant count | Rooming house, building code | Sprinklers required throughout. 13D allowed. |
| Rooms rented separately above the occupant threshold | Small apartment house occupancy | 13R system, licensed design, annual inspection. |
What a rooming house retrofit involves
Physically the job is the same 13D retrofit as any occupied rowhouse, and the cost page band of $2 to $7 per sprinklered square foot applies, with a full house of tenants and finished plaster pushing toward the top. The living through a retrofit article covers how the crew moves room to room. Two things are different. The heads go in every bedroom and every shared space, and there is no skipping the small closets and baths that a single family 13D design can omit, because the engineer is designing to the use rather than to the exceptions, which the rooms that can be skipped article explains. And the control valve has to be where no tenant can close it, because a rooming house has several people with keys and no single person responsible for the system. A locked riser closet, a chain on the valve, or a tamper switch wired to the alarm, which the alarm and monitoring article covers, is the usual answer.
The water supply and the pressure
A rooming house with five or six bedrooms is a full rowhouse, and the remote area for the calculation is the top floor rear bedroom, the farthest point from the riser. The water service that fed the house as a single family rental is the same three quarter inch line, and the water service sizing article covers when it passes and when it does not. There is no special allowance for the use. A house that would have needed a pump as a single family retrofit needs the same pump as a rooming house.
The licensing order
Owners usually come at this backward. They rent by the room first, apply for the license when a tenant or a neighbor asks about it, and learn at the certificate of occupancy stage that the house is being read under a different code than it was built to. The clean order is the reverse. Decide whether the house is a group rental on one lease or a rooming house. If it is a rooming house, get the sprinkler design and the building permit before the first room lease, because the certificate of occupancy for the new use is what the license needs and the sprinkler final is what the certificate needs. The permit steps article covers the DOB sequence and the landlord article covers what to put in each room lease about the heads once the system is in.
The inspection side once tenants move in
A 13D system in a rooming house is still a 13D system, and the inspection intervals article covers what it carries. A 13R system in a house read as a small apartment building carries the commercial inspection calendar, with a tagged annual inspection by a licensed contractor, and the licensing article explains who can sign the tag. The housing inspector who visits a licensed rooming house will ask for the tag, and a lapsed one is a citation on the license rather than a note on a house.
The order to do it in
Count leases, not people. One lease within the household cap is a single family rental and this article does not apply. Separate leases make it a rooming house, and the next question is whether you live there and how many rooms, because that sets which code reads the house and which system it gets. Price the retrofit before you price the rents, since on a six bedroom house the sprinkler line is the largest single cost of making the use legal.
Quick answers
Four roommates on one lease. Do I need sprinklers?
No. A group of unrelated adults sharing a house on one lease is a household under the zoning rules, the house stays a single family rental, and nothing about the sprinkler rules changes. You need the single family rental license and the usual smoke and carbon monoxide alarms.
What makes it a rooming house?
Renting rooms separately, each with its own lease and lock, to people who share the kitchen and baths. The count of people matters less than the arrangement. Once it is a rooming house the District licenses it differently, the building code reads it as a different occupancy, and that is where the sprinkler requirement comes from.
Which system does a rooming house get?
A small one where the owner lives in the house stays under the residential code only if it has a 13D system. A larger one, or one the owner does not live in, is read under the building code, and a 13D system is still the system allowed up to a modest occupant count. Above that count the building is treated like a small apartment house and a 13R system comes in.
Renting by the room, or planning to?
Send the address, the number of bedrooms, and whether you live in the house. We will tell you which code reads it, which system it gets, and what the retrofit runs against the published range.
Call (202) 410-0120