The Building Regulations are performance standards and deal with the health and safety of the occupants and other technical issues such as the conservation of fuel and access to and about buildings.

Almost all loft conversions will require Building Regulations approval, even if they do not require planning permission.

The regulations vary subject to how many stories high your existing property is – if you are converting a loft to a bungalow, many of the fire regulations that apply to a two storey property do not apply. If you are converting an existing three storey building, the regulations will be more stringent than for a two storey property.

In some cases, if you are boarding the loft merely for storage purposes, you will not require building regulations approval but be aware that if an excessive additional load is applied, then the joists will be loaded beyond their design capacity. If you decide to lay flooring boards over the existing joists in the loft space, then this may require a Building Regulations Application to Building Control. Your local Building Control body will be able to advise you on this issue.

There are a number of guidance documents referred to as 'Approved Documents' that contain practical ways and explanations of how to comply with the functional requirements of the Building Regulations.  

We have summarized these below and given examples of how these will apply to a loft conversion project:

Structural stability (Part A)

This regulation deals with the buildings ability to carry anticipated loadings and the general stability of the structure. This will include checking that any new steel beams and other structural components such as floor joists are strong enough.

Some houses have through lounges on the ground floor where the existing load-bearing wall that did take a load down to the foundation has been removed - this beam should be checked to ensure that it is strong enough to carry any new loads from the loft conversion.

Generally the additional load caused by the conversion does not mean a significant increase on the load being transferred to the foundations but, in some cases, the increase in load could be significant and the adequacy of the existing foundations to carry this extra load will need to be checked. 

For many extensions, you will need to appoint a structural engineer to provide calculations for certain elements of the building and these will form part of the application documents.

Fire Precautions (Part B)

This part of the regulations deals with controlling the materials used in the construction of a loft conversion and also making sure that buildings can be evacuated without loss of life. It also covers the risks attached to the spread of fire from one building to a neighbouring building.

When designing an loft conversion, consideration must be given to the ease of escape in the event of a fire and problems caused by creating inner rooms. This often means that additional fire protection will be necessary in the existing parts of the house, such as upgrading doors to fire doors.

This section also deals with the provision of smoke alarms and ensuring that, in certain locations, materials used are able to withstand the spread of fire – e.g. ensuring that existing floors are able fire resistant.

The prevention of dampness (Part C)

This regulations deals with the resistance to contaminants and moisture. It deals with the general ability of floors, walls and roofs to withstand rain and groundwater.

Any new roofs and walls should be properly weatherproofed.

Toxic substances (Part D)

This section deals with toxic substances that will need to be limited in any loft conversion.

Sound resistance (Part E)

Any extension must be properly sound-proofed and this part of the regulations deals with the minimum standards required for both air-borne sound and structure-borne sound.

For example, you will normally be required to provide sound insulation within the floor void of the loft.

Ventilation (Part F)

Ventilation plays a major part in modern building design and this part of the regulations deals with the requirements you will need to put in place to avoid condensation and other health risks.

All habitable rooms will need to have provision for natural ventilation to the outside air (by use of a door or window) which is general 1/20th of the floor area and some rooms such as bathrooms will also need mechanical extraction fans.

This regulation also deals with the provision of ventilation to roof spaces.

Hygiene (Part G)

This part of the building regulations deals with sanitary appliances, water supplies, hot water systems and the provision of washing facilities.

You will need to define and obtain approval for any changes to your existing system and ensure that any new hot water system meets with the requirements.

Drainage and waste disposal (Part H)

Any new drainage or alterations to the existing drains required to build your loft conversion will be covered by this part of the Building Regulations.

Both rainwater (storm) and foul drains are covered and these requirements set standards for minimum falls, cleaning and access provisions, safe disposal of wastes and rainwater, ensuring that they meet health and environmental standards.

You will need to provide minimum pipe sizes for any new waste pipes from bathrooms and you may be required to provide additional manholes where new connection are made.

Heating appliances (Part J)

This regulation deals with the provision of any new heating appliance such as boilers including the safe discharge of flue gases

Stairways (Part K)

Your loft conversion will normally always require the addition of a new staircase and this will be covered under this part of the regulations.

There are numerous requirements on any new staircase including the following:

• The maximum angle of the stairs
• The maximum rise (height) of an individual step
• The minimum length (going) of an individual step
• The provision of landings
• The provision of balustrading and the height of handrails
• Limitation on doors opening near to a staircase

Where there is not enough room for a full traditional stair, it may be possible to use a "space saving" stair – see our section on Loft Conversions – Feasibility for an example.

Conservation of fuel and power (Part L)

All loft conversions will have requirements covered by this part of the regulations that essentially deals with thermal insulation requirements. This part of the regulations is subject to continual change and there are so many requirements, the documents are split into two sections L1 and L2.

Any conversion will have to meet minimum standards for floor, wall and roof insulation and the regulations also cover maximum glazed areas and double glazing requirements.

Access (Part M)

This part of the regulations deals with access to buildings and facilities for disabled people.

The safe positioning of glazing (Part N)

Any new glazing to windows, doors, etc that is installed will have to meet minimum standards and these are covered here.

Electrical safety (Part P)

This is the latest part of the regulations and any new electrical works are now controlled.

Most loft conversions will utilize an approved electrician who is able to self-certify his works but a test certificate will be required in order to get the building regulations completion certificate.

Summary

The above summaries demonstrate that the Building Regulations are wide ranging and extensive documents and really should be dealt with by a professional architect or designer in order to ensure that your new home extension complies.

Sample coming soon