A-Z of Services

Building Control Guidance Note No.7 - A Guide To Loft Conversions

This is one of a series of building control guidance notes which aims to explain the building regulations procedures.

A Guide to Loft Conversions

Are you thinking of converting that unused attic space to extend your home?

If the answer to this question is 'Yes' then this note may help answer some of your questions.

What will the room be used for?
Will I need a new floor?
How will I get to the new room?
Do I want rooflights or windows fitted?

Loft conversions are generally carried out to provide:-

An extra bedroom (maybe with en-suite)
A playroom
A study/office

If you intend to use the attic space to store light items such as suitcases and Christmas decorations then loose boarding is generally satisfactory. You must remember that the ceiling joists are intended to act as a fixing for the ceiling below and are not designed for heavy loads. To prevent any overloading of the ceiling joists it is recommended that the loose boarding does not cover more than 50% of the usable area.

Usable area is that part of the roof space with a headroom greater than 1.5m (approximately 4'6"). Access to this storage area is often by a retractable ladder.

For any use other than light storage you will need to tell your Local Authority, Building Control Section who will advise you on procedures.

Why do I need to tell the Local Authority?

They are responsible for the enforcement of the Building Regulations, which are made to ensure that the buildings are constructed or altered to reasonable standards. In the case of loft conversions the following are examples of those matters that you and/or your builder must consider.
If the space is for a use other than light storage a new floor will have to be provided. New joists will have to be installed and these must be supported and kept clear of the existing ceiling; they are not allowed to rest on the existing ceiling joists.
The existing foundations and lintels may need to be exposed to check they can carry additional loads. The floor and supporting structure may require the insertion of beams or steelwork to support the loft conversion. Structural calculations could be needed to justify the adequacy of these elements
The Building Regulations require where a new storey is to be added by converting an existing roof space, the provisions for escape need to be considered through the full extent of the escape route. For example, a loft conversion to a two-storey house will result in the need to protect a stairway by providing fire resistant doors and partitions and floors where previously no protection existed. This is usually 30 minutes and a correct form of construction will protect you and your family.
In order to prevent unpleasant living conditions, ventilation has to be provided to habitable rooms, bathrooms and kitchens. The regulations require either background (trickle) or rapid ventilation, or in certain circumstances both.
Condensation can also affect areas that cannot be seen such as roof spaces. If this is excessive and remains undetected it can cause problems. Ventilation must therefore be provided to roof spaces and in loft conversions this is particularly important.
To gain access to your new room you will have to consider the type of stair you would like. Ideally you should provide a traditional type that will give safe and easy access. In the event of a fire the need to escape quickly is important.
The walls and roof to the loft conversion must, in addition to keeping out the elements, also keep in the heat. They have to be constructed of materials that help reduce heat loss which can help keep heating costs down. As you may require planning permission, please contact the Planning Control Section on tel: 01978 292017.

General Information

The Party Wall Act 1996 may also apply if you intend to carry out work which involves:-

work on an existing wall shared with another property.
building on the boundary with another property.
excavating near a neighbouring building.

You must determine whether the works fall within the scope of the Act, and where this is the case you must arrange to serve statutory notice on all those, defined by the Act as adjoining owners. You may wish to seek clarification through professional advice.

Also see Building Control Guidance Note No.9 - Your Construction Project and The Party Wall Act 1996.

Make a plan of what you want done. Don't be pressured into unnecessary work or work you can not afford. For large or complex jobs, professional advice may well be needed.
Get the necessary consents or agreements from your local authority and insurance company. Discuss your plans with neighbours, particularly if there are party structures.
Draw up a short list of firms that appear reliable, checking experiences of previous clients, and perhaps references from banks as appropriate.
Find out whether a worthwhile guarantee is available giving cover against a contractor ceasing to trade. Insurance-backed schemes may be particularly appropriate.
Warranties are available in partnership with Local Authority Building Control.
Be as clear as possible about the way you will deal with any disputes.

The Building Employees Confederation (BEC) also offers advice to help you in 'Get the best from your builder'. Also see our Building Control Guidance Note No.2 - Choosing A Builder.

Electrical Safety in Dwellings

With effect from 1 January 2005, Electrical Safety comes under control of Building Regulations. You are advised to ensure all installatiions are carried out by a competent Electrician who has been ‘Part P’ assessed by an approved body. A Certificate of Compliance will need to be given to the Authority issuing their Completion Certificate. Otherwise the Local Authority Building Control Section are responsible for ensuring the installation complies with the requirements, for which an extra charge of £150.00+ vat will be levied on top of the normal charges for the project.

How and when do I tell the Local Authority?

Remember that the Local Authority is there to give advice. The Building Control Officer responsible for your area will be pleased to advise you on the procedures to follow:-

If you decide upon a loft conversion (or any other type of building work) you need to tell the Local Authority by giving them either a) Full plans application or b) Building Notice. If you choose the option of providing a Building Notice then you may be required to provide additional information with respect to specific elements of construction where the nature of the work may be complex or unusual (e.g. in the case of a loft conversion structural engineers calculations are often required for dormer roof and floor structures).

A delay in supplying supportive information can impede the progress of work on site, we strongly recommend that design solutions are agreed prior to commencement of work on site.