Attic Conversions and Planning Regulations

There have been recent changes to the planning regulations on attic conversions, making many conversions exempt from the need make a planning application. In some cases, as an alternative to making a planning application, you may need to make a lesser works declaration; in other cases no consent of any kind is required. The rules that apply depend on the circumstances’, not always capable of easy interpretation.

No Authorisation Required

No authorisation of any kind is required, provided you have existing floorboards, you are not creating any new external openings, and the new surface area is no greater than 10m². Areas less than 1.80m in height are not considered part of the habitable surface area. So, if part of the surface area of a new attic room has space below this height, then you can discount the area for the purpose of assessing the need for planning consent.

Works Application Required

If you have existing floorboards, but the new habitable space is greater than 10m² (but less than 20m²) and/or you are proposing to create new openings in the roofspace, then a works declaration is required.

Planning Application Required

If you do not have existing floorboards, then you are creating a new surface level. If the surface area is greater than 20m² it requires planning permission. Below this figure, then a works declaration only is required. You will also need to make a planning application if you are increasing the height of the external wall in order to create a window opening.

Tax Relief

If you are resident, you can also obtain a tax credit towards insulation works in the attic, carried out as a stand-alone project, or as part of the conversion works. The tax credit amounts to 25% towards the costs of materials, which rises to 40% if carried out (purchased!) within two years of purchase of the property. The tax credit is not available where the conversion works effectively create a surface area within the property, such as the addition of an additional floor surface and/or increasing the external height of the external wall. You can read more in our Guide to the French Planning System.