Most houses have a large space under the roof, normally called the loft or the attic. It is usually wasted, and in a lot of houses it is the cheapest room you will ever add. This guide covers how to tell whether your loft is worth converting, and how the Building Regulations will affect the job.
Suitability
Not all lofts are suitable. Before you get far into planning, go up there and carry out a brief survey. Check:
1.That there is enough height to stand comfortably, bearing in mind that the new floor is likely to sit around 200mm above the existing ceiling joists.
2.That the space is large enough to make a useable room.
3.That there are no chimneys or services passing through the loft that would need moving.
4.That the roof has felt under the tiles, or is otherwise weathertight.
If the answer to all four is yes, the loft may well be suitable for conversion.
How to proceed
Loft conversions are complex, and unless you work in construction you will need professional advice. There are three usual routes.
1.Appoint an architect, an architectural technician or a building surveyor. They prepare the drawings, bring in a structural engineer where one is needed, and obtain the approvals. They can also help you find a builder and run the project for you.
2.Appoint a specialist loft conversion company. These firms offer one route from drawing to finished room: their design side prepares the drawings and obtains the approvals, and their construction side builds it.
3.Use an experienced builder. Some builders do enough loft work to offer much the same package as a specialist. Ask to see two finished ones.
Permissions required
All loft conversions must comply with the Building Regulations. There are two ways of making an application to building control, whether that is your local authority or an approved inspector.
Full plans application. This is the traditional route. Your designer draws up detailed plans and supporting information and submits them with the application form and the fee. Building control check the details, consult the designer where anything needs resolving, and then issue the approval. Work can start 48 hours after the application is received, although it is wiser to wait for the initial check, which usually takes two to three weeks.
A building control surveyor then liaises with your builder and inspects the work as it goes. When the job is finished satisfactorily a Building Regulations completion certificate is issued, which records that the work was independently inspected and complied.
Building notice application. This suits minor domestic work carried out by a competent builder. No plans are formally approved, and the work is signed off on site as it progresses. You or your agent submit a building notice form with a site location plan and the fee, and work can start 48 hours after the notice is received.
When work starts, a surveyor meets your builder to agree how the work will be carried out, when it needs inspecting, and what further information is needed, such as structural calculations or drawings. The completion certificate is issued the same way at the end.
The building notice route is not recommended for a loft conversion unless your builder and designer are very experienced and already know what the local building control body expects. Application forms come from your local authority, by telephone, in person or from their website.
Some loft conversions also need planning permission, especially where a dormer is involved. To confirm whether yours does, contact development control at your local authority.
Party Wall Act
If your loft conversion affects a party wall, you may need to serve notice on your neighbours under the Party Wall Act. There is further guidance on the Planning Portal, and the government publishes a plain English guide to the Act.
If you would like us to look at your loft, tell us about the house, or call the studio on 020 7731 6841.
Published 27 May 2018. Written by the NU Projects studio, edited since for house style and accuracy.