Building Regulations in England: Approval, Inspection and Certificates

Most building work carried out in England must comply with the Building Regulations 2010, made under the Building Act 1984¹. They set standards for the design and construction of buildings to ensure the safety and health of people in or around those buildings, and they include requirements to ensure that fuel and power is conserved³. For a household adding insulation, a heat pump, solar panels, a car charger or an extension, the regulations are the layer that decides whether the work is lawful, not the planning system, which is a separate question with separate rules.

Two routes exist for getting work checked. Either an installer registered with a relevant competent person scheme self-certifies the work, which is instead of getting building regulations approval and means a building control body does not need to be notified, or a building control body is engaged: a local authority building control body, or a private registered building control approver where the work does not include a higher-risk building⁴. In almost all cases of new building work a building control body must be notified in advance of any work starting⁶. On completion the local authority issues a Building Regulations completion certificate, and a registered building control approver issues a final certificate⁷.

For energy fabric, the headline number is Part L. Approved Document L Volume 1 gives a limiting U-value of 0.18 W/(m2·K) for a wall as a new fabric element in an existing dwelling, and 0.26 W/(m2·K) as the limiting value in the Table 3.1 set for new dwellings³. Different rules apply in Scotland and Northern Ireland, which run their own systems entirely⁵.

What the regulations set out to achieve

The stated purpose is narrow and practical. Building regulations set standards for the design and construction of buildings to ensure the safety and health of people in or around those buildings³. Beyond that, they control certain types of building work and ensure that buildings meet certain standards of health, safety, welfare, convenience and sustainability¹¹, and they include requirements to ensure that fuel and power is conserved³. The energy strand is the one most households meet, because almost any measure that improves a home's independence from bought-in energy, insulation, a new heating appliance, glazing, a rooftop array, touches a thermal element, a controlled service or a fitting.

The regulations themselves are short. The detail sits in the Approved Documents, and their status matters: they set out what, in ordinary circumstances, may be accepted as one way to comply with the Building Regulations³. They are not the only way to comply, and they are not the law. The law is the functional requirement; the Approved Document is a route to satisfying it. Building work must meet all relevant requirements of the Building Regulations³.

This is also a moving target. Guidance changed with The Building Regulations etc. (Amendment) (England) Regulations 2021, and the Future Homes and Buildings Standards are to be implemented via the Building Regulations etc. (Amendment) (England) Regulations 2026¹². The Future Homes Standard page covers what that change contains.

England, Wales, Scotland and Northern Ireland are four systems

Building control is devolved, and the differences are structural rather than cosmetic.

Official guidance for England states plainly that there are different rules in Scotland and Northern Ireland⁵. Scotland operates a building warrant system rather than the English notification model, and on completion the owner or client must certify that the works have been constructed in accordance with the building warrant and the building regulations¹⁵. The detail is set out on the Scottish building standards, Welsh and Northern Ireland pages.

One point applies across England and Wales: the building regulations set standards for electrical installation work only in relation to dwellings, houses, flats and similar¹⁷. In industrial or commercial buildings, the Health and Safety Executive is responsible for making sure that electrical installation work is safe¹⁷.

What counts as building work

Regulation 3 of the Building Regulations defines building work, and the definition is broader than most householders expect¹⁸. The following amount to building work¹⁸:

• The erection or extension of a building
• The installation or extension of a service or fitting which is controlled under the regulations
• An alteration project involving work which will temporarily or permanently affect the ongoing compliance of the building, service or fitting with the requirements relating to structure, fire, or access to and use of buildings
• The insertion of insulation into a cavity wall
• The underpinning of the foundations of a building
• Work affecting the thermal elements, energy status or energy performance of a building

Put more simply, the regulations will probably apply where you put up a new building, extend or alter an existing one, or provide services or fittings in a building such as washing and sanitary facilities, hot water cylinders, foul water and rainwater drainage, replacement windows, and fuel burning appliances of any type¹⁸. They may also apply to certain changes of use of an existing building¹⁸.

The last bullet in the list is the one that catches energy retrofit. Work affecting the thermal elements, energy status or energy performance of a building is building work in its own right, which means external wall insulation, a loft conversion's roof build-up, a floor upgrade or a change of heating fuel can all bring the regulations into play even where nothing is being extended. Drainage is a separately listed work section for extensions²⁰. Relining a flue where the work involves a new or replacement flue liner is building work within the meaning of Regulation 3 and must not be undertaken without prior notification to the local authority⁶.

Approval and notification: building control, or a competent person

There are two routes, and the choice is usually made by whoever does the work.

Route one: a building control body. Work is notified to either a local authority building control body or an approved inspector³. Applying for approval from a private registered building control approver is possible in England where the work does not include a higher-risk building; the approver then tells the local authority about the work, which is called giving an initial notice⁵. Where a building control body is used, a deposit of a Building Regulations application is made with the building control team, as either full plans or a building notice²¹. Full plans mean the design is checked before work starts; a building notice is the lighter route, with the work assessed on site.

Route two: self-certification. An installer, for example of windows or boilers, who is registered with a competent person scheme can self-certify that their work complies with building standards⁴. Approved installers who join a scheme can self-certify certain types of building work, and this is instead of getting building regulations approval²². Work carried out under a competent person scheme does not need notification to building control²³, and a building control body does not need to be notified for certain types of services or fittings, including fuel-burning appliances or replacement windows, where the owner employs an installer registered with a relevant scheme designated in the regulations³. The mechanics are set out on the competent person schemes page.

Notifiable work must be reported to the local building control body unless completed by someone registered on the competent person scheme²⁴. The rule holds for domestic EV chargers: if the work is not done by a person registered with the competent person scheme, then the relevant building control authority must be notified of the work²⁵. For electrics generally, the building control body or registered third-party certifier must be notified before work starts¹⁷.

Anyone carrying out, or having done, construction or building work may also need to notify the Health and Safety Executive and may have other duties as well¹⁸. That is a separate duty from building control notification, not a substitute for it.

Work that does not need to be notified

Not everything is notifiable. For electrical work in homes and gardens in England and Wales, you do not need to tell building control about repairs, replacements and maintenance work, or extra power points or lighting points or other alterations to existing circuits, except in a kitchen or bathroom, or outdoors²⁷. The regulations allow certain works, known as non-notifiable or minor work, to be carried out without notifying building control or using a registered electrician²⁷. The same framing appears in England guidance: most repairs, replacements and maintenance jobs, and alterations or additions to existing circuits outside special locations, fall outside notification¹⁷.

Examples of work that need not be notified to the council, where it is not in a kitchen or special location and does not involve a special installation, include²⁸:

• Adding lighting points, light fittings and switches, to an existing circuit
• Installing or upgrading main or supplementary equipotential bonding

Non-notifiable does not mean unregulated. Like notifiable work, it should be designed and installed, and inspected, tested and certificated in accordance with BS 7671²⁹. The standard itself is covered on the electrical safety regulation page.

Elsewhere, repairs, maintenance and minor improvements will not require an application, for example on a bay window replacement³⁰. Work to the roof of a house such as re-roofing that does not materially affect its external appearance will usually not require planning permission³¹, though that is a planning point and leaves the building regulations position untouched. Building regulations and planning permission are distinct consents: one may be needed without the other.

Exempt buildings and projects

Some kinds of building projects are exempt from the regulations¹⁹. Exemption in England is organised by class, with Class 1, buildings controlled under other legislation, exempt from Parts A to K, M, N and Q³².

Separately, Part 2 of The Energy Performance of Buildings (England and Wales) Regulations 2012 carves out a set of buildings from the energy certificate duties³³:

• Buildings used as places of worship and for religious activities
• Temporary buildings with a time of use of two years or less
• Industrial sites, workshops and non-residential agricultural buildings with low energy demand
• Residential buildings used, or intended to be used, for less than four months of the year

Regulation 21 excludes listed buildings, buildings in a conservation area and scheduled monuments where compliance would unacceptably alter their character or appearance, along with places of worship, temporary buildings with a planned time of use of two years or less, industrial sites, workshops, non-residential agricultural buildings with low energy demand, and stand-alone buildings other than dwellings with a total useful floor area of less than 50m2²⁶. Requirement L3 does not apply to a building which is a relevant building for the purposes of regulation 7(4) of the Building Regulations 2010⁸. The heritage side is covered further on the listed buildings and conservation areas page.

Scotland handles exemption differently again: regulations 8 to 12 do not apply to any building, or services, fittings and equipment, the whole of which falls into an exempted type in schedule 1¹⁵.

Part L: conservation of fuel and power

Part L is where the regulations bear directly on a household's energy use, and therefore on how much bought-in energy a home needs. The figures are limiting U-values: the worst performance an element may have, not a target.

The spread in that table is not a contradiction so much as a set of different questions. 0.18 W/(m2·K) is the value applied to a new fabric element inserted into an existing dwelling in England, which is why a household insulating a solid wall meets that figure rather than the new-build one³. The 0.26 W/(m2·K) entry is a limiting value from the new-dwelling table, and limiting values in new build sit alongside a whole-dwelling calculation, so an individual element at the limit is only acceptable if the building as a whole passes. The Scottish 0.70 W/m2K figure is an individual-element value in a different regulatory system and is not comparable with the English tables³⁶. Where a maximum permitted U-value is needed for a specific element such as a rooflight, Approved Document L Volume 1, Table 4.2 is the reference³⁷.

For a household, the practical consequence is that a Part L upgrade is the one piece of building regulation that permanently reduces demand. A wall brought to 0.18 W/(m2·K) keeps working with no supplier, tariff, app or contract behind it. The dependence that remains is on the calculation method and on the guidance itself changing: the Approved Documents are revised, and the Home Energy Model is replacing SAP as the underlying assessment.

Who is responsible if the work does not comply

People responsible for building work, whether agent, designer, builder or installer, must ensure that the work complies with all applicable Building Regulations requirements⁷. Where a householder employs a builder, the responsibility will usually be theirs, but this should be confirmed at the very beginning¹⁹.

The qualification matters, because the ultimate exposure does not move. If you are the owner of the building, it is ultimately you who may be served with an enforcement notice if the work does not comply with the regulations¹⁰. Local authority guidance puts it more bluntly still: ensuring home improvements comply with building regulations is the homeowner's responsibility³⁸, and the owner of the property or land is responsible for meeting the relevant planning rules and building regulations³⁹. Scotland reaches the same place by a different route, with the duty to comply lying with the owner, or in some cases the client, for the work¹⁵.

For heating specifically, where an existing system has been altered or replaced, the person who last worked on the system is responsible for its safe running and should issue a certificate showing the necessary checks have been carried out⁴⁰. Where Regulation 7A applies, on the erection of a building, the person carrying out the building work must give notice to that effect to the local authority⁴¹.

Enforcement, certificates and unauthorised work

Regulation 18 of the Building Regulations 2010 defines unauthorised building work, in the England version, as building work, other than work in relation to which an initial notice, an amendment notice, a public body's notice or a regulator's notice has effect, which is done without a building notice, an application for building control approval with full plans, or a notice of intention to start work in the circumstances specified⁴². The Wales version is the same save that it omits the regulator's notice⁴².

The consequences are stated in official guidance rather than quantified: you may have to correct the work or pay a fine if building regulations are not followed⁴, and the person doing the work could be prosecuted and fined if they do not comply². Where building regulations approval is not given, the work should be changed so it meets standards²⁴. No penalty figure is published in the guidance covered here, so any sum quoted elsewhere should be checked against the legislation itself.

On the certificate side, the process is:

1. The work is notified, by full plans or building notice, or self-certified by a registered competent person²¹.
2. The building control body inspects the work as it proceeds.
3. Where electrical work is involved and inspected by the council surveyor, an Electrical Installation Certificate signed by a competent person must be provided; until that certificate is received, a completion certificate for the whole of the works cannot be issued²¹.
4. Once the body decides the work meets all the Building Regulations requirements, it issues a Building Regulations completion certificate if it is a building control authority, or a final certificate if it is a registered building control approver⁸.

An EPC is a separate document on a separate timetable: nothing in Part 2 of the 2012 Regulations requires an energy performance certificate to be given or made available to a prospective buyer or tenant at any time before the construction of the building has been completed³³. See EPC regulations and reform.

Extensions, glazing, conservatories and solar: how existing homes differ

Building regulations will generally apply if you want to build an extension to your home⁹. Conservatories are the main exception, and the conditions are specific. They are normally exempt from building regulations when they are⁹:

• Built at ground level and less than 30 square metres in floor area
• Single storey
• Separated from the house by external quality walls, doors or windows
• Fitted with an independent heating system with separate temperature and on/off controls
• Built with glazing and any fixed electrical installations complying with the applicable building regulations requirements

Any new structural opening between the conservatory and the existing house requires building regulations approval, even if the conservatory itself is an exempt structure⁹. In practice that is where most conservatory projects re-enter the system.

Glazing is covered twice over. Replacing windows and doors is listed among the work that building regulations approval covers², and the self-certification route through a registered installer is the usual means of discharging it³. Planning is separate and turns on appearance: for a flat or maisonette, replacement windows do not require planning permission so long as they are identical like-for-like replacements in terms of appearance and material, while permission is likely to be required if they would not match the appearance and material of the existing windows, including glazing type, for instance single glazing to double or triple glazing and the reverse⁴⁴. For a listed dwelling house, planning permission would be required for the installation of replacement windows⁴⁴.

Solar sits at the same junction. Building regulations will normally apply to installing solar panels on a roof⁴⁵, and a building regulations application is required, with the roof strength assessed and possibly needing strengthening, and the regulations also covering the electrical installation⁴⁶. Local guidance frames the electrical works as the reason approval may be needed⁴⁷. On planning, placing solar panels on the roof of a house or flat, or on a building within its grounds, is in most cases permitted development under Schedule 2, Part 14, Class J of the Town and Country Planning (General Permitted Development) (England) Order 2015⁴⁵, and installation on residential buildings may be permitted development with no need to apply for planning permission⁴⁸. Solar panels on listed buildings need planning permission and listed building consent, which must be obtained before work commences⁴⁶. See permitted development rights for the wider picture.

Roof work follows the same pattern of planning exemptions that do not touch the building regulations. Permitted development for other alterations to the roof of a dwellinghouse sits in Schedule 2, Part 1, Class C of the 2015 Order, and requires that the current house is not a building containing one or more flats, or a flat contained within such a building, and was not built as a new dwellinghouse under permitted development rights³¹. In Scotland, demolition or alteration of the roof, external walls or an element of structure is excluded from the house-work exemption¹⁵.

What this means for a household's independence

The building regulations do not stop a household generating, storing or insulating. They set the conditions on which it may do so, and in the energy case those conditions mostly push in the same direction as independence: Part L drives demand down, and the electrical requirements make on-site generation and charging safe to connect. What the system costs a household is time, a fee to a building control body or a registered installer, and a record. What it gives back is the certificate that proves the work was done properly.

Three dependencies remain visible. The first is on registered installers: the self-certification route only works if a scheme member does the job, which narrows the field of who may lawfully carry out notifiable work. The second is on the building control body itself, local authority or private approver, whose sign-off the household cannot supply for itself. The third is on the rules changing: the Approved Documents are amended, and the Future Homes and Buildings Standards arrive through the Building Regulations etc. (Amendment) (England) Regulations 2026¹². A measure compliant today remains lawful, but the standard the next measure must meet is set elsewhere. The wider framework sits in the regulation and policy guide.