Adding value with a garden room: 5 considerations

Garden rooms are a property asset that gained popularity during the pandemic but recent analysis of Google data by Legal & General revealed that searches for outbuildings are still incredibly high.

In fact, between August 1st 2023 and July 31st 2024, Google searches for ‘garden rooms’ topped just over 1 million, while the phrase ‘summer house’ was searched for 726,000 and 'garden offices’ 397,200.

Property professionals have also noted that garden rooms can have a positive effect on property values. Homes with an outdoor room can fetch between 5% and 15% more than similar properties without, returning a profit as long as the budget to construct the outbuilding doesn’t exceed the value added.

A garden room can provide a great space away from the distractions of the main house, with many used as home offices, gyms, games zones, mancaves and hobby rooms.

Planning permission: usually not required

Most garden rooms can be added without the need for planning permission. This is because the owner will have permitted development rights and a garden room is classed as an outbuilding.

Permitted development rights explained

Permitted development rights allow homeowners to improve, add to or alter their home without the need for planning permission. This right usually covers garden rooms, as long as...

• The garden room is not at the front of the property
• All extensions, sheds and outbuildings do not cover more than 50 percent of the total area of land around the property
• The garden room is more than 2 metres from the boundary, single storey and less than 3 metres high (4 metres with a dual-pitched roof)
• The garden room is within 2 metres of your boundary but is no more than 2.5 metres high
• The eaves do not exceed 2.5 metres above ground level
• The garden room does not have a balcony, veranda or raised platformThe garden room isn’t to be used as self-contained living accommodation

There are exceptions, however. You may not have permitted development rights and may need to apply for planning permission if you.

• Live in a flat
• Live in a maisonette
• Live in a protected area, such as a National Landscape, a National Park, a conservation area or a World Heritage Site

Building regulations

If the garden room isn’t attached to your main home, has a floor area of less than 15 sq m and doesn’t include sleeping accommodation, building regulations won’t apply. Any electrics in your garden room will, however, need to comply with part P of the building regulations. You’ll also need a certificate showing that the installation meets the relevant regulations when you sell your property.

Heating a garden room

One of the biggest garden room mistakes is not planning a way to heat the space. As a small, stand-alone structure, a garden room won’t draw heat from other rooms and depending on its orientation, may not benefit from the sun coming in. A good source of heating is essential if the room is to function as a home office.

Heating by mains gas won’t be feasible in most cases but there are alternatives. Electric radiators, convection heaters and electric underfloor heating are popular options for rooms that are used on a regular basis – especially if they can be operated using an app or timer. Fan heaters, infrared heaters and oil fired radiators are other considerations, as are log burners if the space is big enough and there is adequate ventilation.

Insulation is key

There’s no point spending money on heating a garden room if the warmth quickly escapes, so don’t skip insulation. Opt for an additional, heat-retaining material, such as rockwool, in the walls, floor and ceiling. All doors and windows should be double glazed, with trickle vents and openings. Keeping an even temperature in a garden room will also prevent condensation and mould, which isn’t ideal in a home office or where there are soft furnishings.

Adding a garden room is a great way to increase your home’s value, increase the usable square footage and provide potential buyers of the future with a unique bonus room. If you’d like to discuss the value you could add to your home ahead of a sale, please get in touch.