Do you need Building Regulations approval?

What counts as building work

Regulation 3(1) lists nine kinds. Those that catch home projects are:

• the erection or extension of a building (3(1)(a));
• the provision or extension of a controlled service or fitting (3(1)(b)), meaning anything Parts G, H, J, L or P of Schedule 1 cover: water, drainage, combustion appliances, energy efficiency and electrics. Replacement windows and external doors are controlled fittings;
• a material alteration (3(1)(c));
• work needed because of a material change of use (3(1)(d)), such as a house becoming flats (regulation 5(b));
• cavity wall insulation (3(1)(e)) and underpinning (3(1)(f)).

An alteration is material if, at any stage, it would leave the building failing a requirement it used to meet, or further from one it already failed (regulation 3(2)). The requirements that count are in regulation 3(3): structure (Part A), escape, fire spread and fire service access (B1, B3, B4, B5), access (Part M) and toilet accommodation (Part T). Removing a load-bearing wall touches structure; a loft bedroom touches structure and escape.

Exempt buildings: Schedule 2

Regulation 9 disapplies the regulations for the buildings in Schedule 2, apart from some water and electrical requirements where supplies come from the house (9(2) and (3)). Two of its seven classes matter for houses.

1. A detached single storey building, having a floor area which does not exceed 30m², which contains no sleeping accommodation and is a building: (a) no point of which is less than one metre from the boundary of its curtilage; or (b) which is constructed substantially of non-combustible material.
2. A detached building, having a floor area which does not exceed 15m², which contains no sleeping accommodation.

The extension of a building by the addition at ground level of: (a) a conservatory, porch, covered yard or covered way; or (b) a carport open on at least two sides; where the floor area of that extension does not exceed 30m², provided that in the case of a conservatory or porch which is wholly or partly glazed, the glazing satisfies the requirements of Part K4, K5.1, K5.2, K5.3, and K5.4 of Schedule 1.

Three details often missed:

• "Does not exceed" includes the figure itself. Exactly 15 m² or 30 m² is inside the class, although several Planning Portal pages say "less than".
• Sleeping accommodation takes a building out of Class 6 whatever its size, and adding a bedroom to an exempt garden building later is itself a material change of use (regulation 5(f)). See annexes and garden rooms and sheds.
• A Class 7 conservatory or porch comes back under the energy efficiency requirements if the wall, door or window between it and the house is removed and not replaced, the house heating is extended into it, or a fixed heating appliance is provided to heat it (regulation 21(4)). The Planning Portal adds that a new structural opening into an exempt conservatory needs approval in its own right.

Work that needs no application

Competent person schemes. Regulation 12(6)(a) and Schedule 3 let a registered installer self-certify set types of work, including gas appliances (paragraph 1), electrical installations in dwellings (paragraph 8), replacement windows, rooflights and doors in a dwelling (paragraph 10), bathrooms that do not touch shared or underground drainage (paragraph 12), microgeneration (paragraph 15) and replacement roof coverings (paragraph 16). Within 30 days of finishing, the installer must give you a copy of the certificate and notify building control (regulation 20(3)). Keep it for when you sell.

Minor work in Schedule 4. For example, replacing an external door no more than 50% glazed (paragraph 1(h)); replacing a toilet, basin, sink, bath, shower, gutter or downpipe, with conditions on drainage and water (paragraph 1(j)); laying loft insulation on its own (paragraph 1(m)).

Electrics. In England, electrical work must be notified, done by a registered electrician, or inspected by a registered third-party certifier appointed before it starts (regulation 12(6)(c) and Schedule 3A), if it is a new circuit, a replacement consumer unit, or work to circuits in a special location such as the space around a bath or shower (regulation 12(6A)). Other electrical work needs no notice but must still meet Part P.

Common home projects in England

What this means for you

Place your project in one of the three categories first. If exempt, check the exact wording above. If a trade will self-certify it, confirm they are registered for that type of work. If it needs approval, choose the route: full plans or a building notice, with the council or a registered building control approver. The route finder walks through it. Work already done without approval goes through regularisation.

Building Regulations approval is separate from planning permission, and you may need both. This guide covers England; Wales has its own versions of several of these provisions.

Parallel Architecture coordinates the Building Regulations information for the projects it designs. Get in touch to talk a project through.