A vacant DC rowhouse with fire sprinklers: keep it wet and heated, or drain it, and what the District charges while it sits

Houses sit empty in the District for ordinary reasons. An estate in Petworth waits on probate. A flip in Trinidad waits between demolition and the next permit. A Capitol Hill rental waits two months for the next tenant. If the house has a sprinkler system, the empty months are the ones that break it, and the breaking has nothing to do with fire. Here is the decision an owner has to make the week the last person moves out, what the District does about vacant buildings, and the short list that keeps the system alive until someone lives there again.

The risk is cold, not fire

A sprinkler system in a house is a wet system. Every pipe is full of water at street pressure, all the time, and that is what makes it work with no pump and no power. It is also what makes it the most vulnerable thing in an empty house in January. When nobody is paying the gas bill the thermostat gets turned down or the heat gets turned off, the rear addition drops below freezing first, the water in the branch line freezes, and CPVC and copper both split. The split does nothing until the thaw. Then the line runs at street pressure into a closed ceiling with nobody home to hear it, for as long as it takes someone to notice the water bill or the neighbor to notice the party wall.

Every spring the inspection page list fills with houses that were empty over the winter. The freeze protection article covers the pipe routing side. This one covers what the owner does.

Option one: keep it wet and keep it heated

This is the right answer for any house that will be occupied again inside a year. Leave the water on, leave the system in service, and keep the heat at 55 degrees or better on every floor, including the rear addition and the cellar, which usually sit on separate thermostats or no thermostat at all. The house stays protected, which matters more when it is empty than when it is full, because nobody is there to smell smoke. The insurance sprinkler credit from the insurance article stays in force, and the buyer or tenant who comes next inherits a system with no gap in its record.

The cost is the heating bill. On a brick rowhouse with the thermostat at 55 that is a real number but a known one, and it is smaller than one split line.

Option two: drain it, and know what that means

A house with the heat off for the winter, or a gut renovation with the ceilings open and the furnace disconnected, gets drained. Draining a 13D system is not the same as shutting the valve. The control valve closes, the main drain at the riser opens, and the high points are vented so the water actually leaves the pipe instead of sitting in trapped sections of CPVC where it can still freeze. Low point drains, if the system has them, get opened. On a system with no low point drains the branch lines in a rear addition may need a fitting cracked.

A drained system is a dead system. The house has no fire protection until it is refilled, and that has to be said out loud to the insurer, because a policy that carries a sprinkler credit on a drained system is a claim waiting to be denied. Tag the riser with the date it was drained and who drained it. When the house is ready to be occupied, a licensed contractor refills it, bleeds the air, checks every joint the drain down touched, runs a main drain test, and tags it again. On a rowhouse that is a short visit, and it is part of the handover file the selling article describes.

What the District does about a vacant building

DC takes vacant houses seriously because it has a lot of them. An owner of a building that becomes vacant is required to register it with the Department of Buildings, and a registered vacant building is taxed at the Class 3 rate, several times the normal Class 1 residential rate. A building the District designates as blighted moves to Class 4, higher again. The exemption that matters to a renovation is the one for a building under an active building permit with work actually underway, which is available for a limited period and has to be applied for, not assumed.

The sprinkler system crosses this in one place. A permit that includes the sprinkler work is evidence of active construction, so a renovation that stalls between the demolition permit and the build permit can lose its exemption while the house sits open and drained. Keep the permit moving, and the permit timeline article says how long each step takes.

The insurance vacancy clause

Most homeowner policies change what they cover after a house has been empty for a set number of days, and water damage and vandalism are the two coverages that usually go first. That is exactly the pair a drained or frozen sprinkler system produces. Before the house is empty for a month, call the carrier, say the word vacant, and ask what changes and whether a vacant dwelling endorsement or a builder's risk policy is the right replacement. Say whether the system is wet or drained. The carrier writes it down, and that note is the difference between a paid claim and an argument.

Theft, and the one thing to lock

An empty rowhouse with an unlocked rear door loses its copper. The riser is a tempting target, with brass valves and a backflow preventer worth real money as scrap. A stolen backflow preventer leaves the water service open to the cellar floor. Lock the cellar door, lock the riser room if there is one, and if the house will be empty for months, ask DC Water to lock the curb stop. A locked curb stop means the system is dead, so that is a drained house decision, not a wet house one. The backflow article covers what a replacement involves.

Keep the water account open

A wet system needs DC Water on. An account that lapses for nonpayment gets shut at the curb, and nobody tells the sprinkler system. Keep the account in the owner's or the estate's name, keep it paid, and expect the minimum charges to continue. The water service page explains which part of the pipe is DC Water's and which part is yours.

The walkthrough that keeps a wet system alive

Once a week, or once every two weeks in mild months, someone goes through the house and checks five things. Write the date and the readings on a sheet taped to the riser.

1. The thermostat on every floor reads 55 or better, and the rear addition is warm to the hand.
2. The riser gauge reads about what it read last time. A drop means a leak or a DC Water problem.
3. The control valve is open, locked or tagged, and nobody has closed it.
4. No drips at any head, no stain on any ceiling, no sound of running water.
5. The cellar is dry and the backflow preventer is where it was.

A house that passes that list every week for a winter comes back into service with a thirty second gauge check. A house that nobody walked comes back with an invoice.

Quick answers