Does an open fireplace affect my EPC?

Yes. An open chimney can quietly take heat out of the house all day long, even when nobody lights the fire.

If the fireplace is redundant, dealing properly with the open flue can reduce draughts and sometimes recover useful EPC points.

But keeping the fireplace does not necessarily mean keeping an open fire. One option may be to replace it with a closed-room wood-burning stove, which can retain the character of the fireplace without the same EPC disadvantage.

THE WORKSHOP JOURNAL

A traditional British sitting room with an unlit open fireplace.

What actually makes the difference?

The first question is what is sitting in the fireplace now, and whether you still want to use it.

A working open fireplace

A working open fire needs a permanently open route for combustion gases and an adequate supply of combustion air.

That open chimney also allows warm room air to escape when the fire is not burning.

If you value the open fire and use it, keeping it may still be the right decision. You just need to understand that it can work against the EPC.

An unused open fireplace and flue being inspected.

Unused or redundant

Not lighting the fire does not make the chimney disappear.

If the flue remains open, heated air can continue escaping from the room while colder outside air replaces it. That contributes to heat loss and can create a persistent draught.

In this situation, the house can effectively be paying an energy penalty for a fireplace nobody uses.

Where the fireplace and any associated appliance are permanently out of use, the open flue may be capable of being closed or altered appropriately.

That should be done properly. Simply stuffing something into the opening is not the same as dealing correctly with a redundant chimney, and moisture and ventilation within the chimney still need consideration.

A closed-room wood-burning stove fitted within a traditional fireplace.

A closed-room stove

There is another route.

If you like the fireplace and want to retain a working fire, a closed-room wood-burning stove may be worth investigating.

Our investigations have shown that replacing an open fireplace with a closed room heater burning wood logs does not necessarily harm the EPC rating. In some cases we have actually seen the rating improve.

The precise result depends on the rest of the property and how the appliance is represented in the assessment, so it should be tested rather than assumed.

Keeping a real fire does not automatically mean keeping an open fireplace.

A properly installed closed appliance can give you another option.

The Workshop Journal beside fireplace investigation notes.

What we’ve found in the Workshop

There is a consistent difference between an open fireplace and a closed room heater.

Open fireplaces can contribute to ventilation heat loss through the permanently open chimney. Removing that open-flue effect can recover useful EPC points, particularly where several small improvements are being combined to reach the next rating band.

But the lesson isn’t simply:

“Get rid of the fireplace.”

In properties where retaining a real fire matters, modelling a closed-room wood-burning stove has shown that the fireplace can sometimes be kept without the EPC penalty of the original open fire.

We’ve even seen cases where introducing the closed room heater improved the EPC rating, although that behaviour deserves further investigation before we treat it as a universal rule.

The important thing is to test the options rather than assume that character and energy performance are automatically at odds.

Before you change anything

• First establish whether the chimney serves a working fire, stove or other appliance. Never obstruct a flue that is required for safe combustion.

• Then decide what you actually want from the fireplace.

• If it is no longer wanted, investigate an appropriate way of dealing with the redundant opening.

• If you want to keep a real fire, investigate whether a suitable closed room heater (wood logs) offers a better solution than retaining the open fireplace.

• Any alteration needs to take account of safe flue operation, combustion air, chimney condition, moisture and ventilation. Planning, listed-building or conservation restrictions may also apply.

• And if the EPC matters, model the alternatives before committing to the work.

A cutaway view of a traditional house showing the fireplace, flue and chimney stack.

A traditional British home considered as part of an EPC improvement review.

What does this mean for your home?

For a landlord, an unused open chimney can be a relatively inexpensive opportunity to recover some EPC performance before considering more disruptive measures.

For a homeowner, removing an unwanted draught may noticeably improve comfort even where the EPC gain is modest.

But if the fireplace is part of the character of the house and you want to keep using it, the decision does not have to be fireplace versus EPC.

A closed-room wood-burning stove may allow you to retain that feature while avoiding the disadvantage of an open fire.

The building gets a vote, but so do you.