Building Regulations in England: Approval, Inspection and Certificates

Building regulations set standards for the design and construction of buildings to ensure the safety and health of people in or around those buildings¹. In England, most building work must comply with the Building Regulations 2010, which cover the construction and extension of buildings². They also include requirements to ensure that fuel and power is conserved, which is why they matter to anyone installing a heating system, insulation, solar panels or new windows³. They are separate from planning permission: planning deals with whether a project is acceptable in principle and how it looks, while building regulations deal with how it is built.

The system works through approval, inspection and certificates. In almost all cases, work must be notified to a building control body before it starts, either a local authority team or a private registered building control approver⁴. Some work can instead be self-certified by an installer registered with a competent person scheme, which is instead of getting building regulations approval⁵. At the end, the building control body issues a completion certificate, or a final certificate if the body is a private approver⁶. This page explains each stage, what counts as building work, what is exempt, and what happens if the rules are ignored.

The aims of the rules

Building regulations exist to ensure the safety and health of people in or around buildings¹. The Building Regulations 2010 cover the construction and extension of buildings in England, and building work must meet all relevant requirements of them². The requirements themselves are short legal statements, and they reach well beyond structure and fire safety: they also include requirements to ensure that fuel and power is conserved³, which is the hook on which most home energy work hangs.

The practical guidance comes in the Approved Documents. These set out what, in ordinary circumstances, may be accepted as one way to comply with the Building Regulations⁴. That wording matters: the Approved Documents are guidance, not the law itself, and a builder can propose a different way of meeting a requirement, though most follow the documents because doing so is the straightforward route. For a household, the documents are the reference point for what an inspector will look for, from the U-value of a new wall to the ventilation that must accompany tighter insulation.

The guidance changes over time. The Building Regulations etc. (Amendment) (England) Regulations 2021 changed the guidance, including the Approved Documents, from June 2022⁸, and the Future Homes and Buildings Standards are to be implemented via the Building Regulations etc. (Amendment) (England) Regulations 2026⁹. A project approved under one edition is judged against that edition, which is one reason the date of an application matters.

Four nations, four systems

The Building Regulations 2010 apply to England², and the 2021 amendment regulations apply in relation to buildings and building work in England¹⁰. Wales shares much of the historical framework, and some regulations extend to England and Wales, but Wales now issues its own guidance: the Welsh Approved Document L, for example, is a separate consultation document with its own figures¹¹. Electrical installation work in homes and gardens in England and Wales must comply with the building regulations¹².

Scotland and Northern Ireland are different systems altogether. The UK government states plainly that there are different rules in Scotland and Northern Ireland¹³. In Scotland, the building regulations always apply where construction occurs, unless exempted by regulation 3, and construction includes alterations and extensions as well as entirely new buildings; the duty to comply lies with the owner, or in some cases the client, and on completion the owner or client must certify that the works have been constructed in accordance with the building warrant and the building regulations¹⁴. Northern Ireland has its own Building Regulations 2012, intended to ensure the safety, health, welfare and convenience of people in and around buildings¹⁵.

This page is about England. The same principles of approval, inspection and certification run through all four systems, but the bodies, the documents and the thresholds differ, and a household in Cardiff, Edinburgh or Belfast should read the rules for its own nation. We cover those separately in building regulations in Wales, Scottish building standards and building regulations in Northern Ireland.

Which jobs count as building work

Building work is defined in regulation 3 of the Building Regulations¹⁶. The Planning Portal lists the types of project that amount to building work, and the list is broad¹⁷:

• 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

The regulations will probably apply if you want to put up a new building, extend or alter an existing one, or provide services and 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 type¹⁶. They may also apply to certain changes of use of an existing building¹⁶. The Welsh list is materially the same, including the insertion of insulation into a cavity wall¹⁸.

Two points catch households out. First, "controlled services and fittings" reaches deep into home energy work: hot water cylinders, fuel burning appliances of any type, and drainage are all named¹⁶. Second, the alteration category is not about size but about effect: work that affects ongoing compliance with the structure, fire or access requirements is building work even if it looks minor. Even relining a flue during renovation, refurbishment or repair is building work within the meaning of regulation 3 and must not be undertaken without prior notification to the local authority¹⁹.

Getting sign off: building control or a registered installer

Once work counts as building work, there are two routes to lawful compliance. The first is approval from a building control body. There are two types: a local authority building control body, and a registered building control approver⁴. You can apply for approval from a private registered building control approver in England if the work does not include a higher-risk building; the approver will tell the local authority about the work, called giving an "initial notice"¹³. In almost all cases of new building work it is necessary to notify a building control body in advance of any work starting¹⁹.

The second route is 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 standards, and this is instead of getting building regulations approval⁵. Notifiable work must be reported to the local building control body unless completed by someone registered on the competent person scheme²⁰. For electrical work, the choice is stated as either arranging for the works to be inspected and tested by a person who is a member of the Competent Person Scheme, or depositing a Building Regulations Application with the Building Control Team, as full plans or a building notice²¹. We cover the schemes in more detail in competent person schemes.

Timing is strict. The building control body or registered third-party certifier must be notified before work starts¹². For new buildings, the person carrying out the work must give the local authority notice of the CO2 emission rate calculations and the fabric energy efficiency rate calculations not later than the day before the work starts⁶, and in any case other than a higher-risk building, notice that the energy analysis has been undertaken and documented must be given not later than the beginning of the day before the day on which the work starts²².

Jobs you need not tell anyone about

Not everything needs a building control application. The Building Regulations allow certain works, known as non-notifiable or minor work, to be carried out without having to notify building control or use a registered electrician²³. For electrical work in homes and gardens, you do not need to tell the building control body about repairs, replacements and maintenance work, or about extra power points or lighting points or other alterations to existing circuits, except in a kitchen or bathroom, or outdoors²³. Most repairs, replacements and maintenance jobs, and alterations or additions to existing circuits outside special locations, fall outside notification¹².

Local authority guidance fills in the detail. Work that need not be notified to the council includes adding lighting points, light fittings and switches, to an existing circuit, and installing or upgrading main or supplementary equipotential bonding, where the work is not in a kitchen or special location and does not involve a special installation²⁴. The same authority states the other side of the line: notifiable work must be inspected and tested either by a member of the Competent Person Scheme or through a Building Regulations Application²¹.

There is also a notification exemption built into the approval system itself. For certain types of services or fittings, including fuel-burning appliances or replacement windows, a building control body does not need to be notified if the owner employs an installer registered with a relevant competent person scheme designated in the regulations⁶. In other words, the work is still regulated, but the registered installer's self-certification replaces the notification. The distinction matters when something goes wrong: work that was never notifiable has no certificate trail to worry about, whereas work that was notifiable but self-certified should have been certified by the installer.

Buildings and projects outside the rules

Some kinds of building projects are exempt from the regulations¹⁷. In Scotland, regulations 8 to 12 do not apply to any building or any services, fittings and equipment the whole of which falls into an exempted type in schedule 1, and any demolition or alteration of the roof, external walls or element of structure is excluded from the house-work exemption¹⁴. England's exemptions work on the same principle: whole classes of building or project sit outside the system.

The Energy Performance of Buildings (England and Wales) Regulations 2012 exclude from their Part 2: 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; and residential buildings used or intended to be used for less than four months of the year²⁵. Regulation 21 of the Building Regulations 2010 similarly excludes buildings listed or in a conservation area or scheduled monuments where compliance would unacceptably alter their character or appearance, 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 50m2²².

For householders, the exemptions that bite are the small ones. A stand-alone building other than a dwelling under 50 square metres is outside the Part L requirement²², and a conservatory under 30 square metres is normally exempt, as section 10 below sets out. But exemption is never a licence to build badly: the exemption for conservatories still requires the glazing and fixed electrical installations to comply with the applicable requirements⁷.

Part L: saving fuel and power

Part L is the part of the Building Regulations that conserves fuel and power, and it is the part most home energy projects touch. The Approved Document L, Volume 1: Dwellings, in its 2021 edition incorporating 2023 amendments, sets the standards for England⁶. Its limiting U-values cap how much heat a fabric element may lose. For new fabric elements in existing dwellings, Table 4.2 gives a maximum wall U-value of 0.18 W/(m²·K)⁶. For new dwellings, the Welsh consultation version of Approved Document L gives a wall value for dwelling houses of 0.18 W/(m²·K)¹¹, while Table 3.1 of the current Approved Document L gives a limiting wall U-value of 0.26 W/(m²·K) for new dwellings⁶.

These figures are not interchangeable, and it is worth being precise about which is which. The 0.18 W/(m²·K) figure is the standard a new wall is actually expected to achieve, in both England's guidance for existing dwellings and the Welsh consultation for new dwelling houses⁶. The 0.26 W/(m²·K) figure is a limiting value in Table 3.1: a backstop that no element may exceed even if the dwelling as a whole passes its overall energy performance targets⁶. A wall built to 0.18 comfortably clears the backstop; a wall built only to the backstop would usually fail the dwelling-level calculation.

Part L also drives the paperwork before work starts. The requirement for CO2 emission rate and fabric energy efficiency rate calculations, notified not later than the day before work starts⁶, and the notice that the energy analysis has been undertaken and documented²², both sit in this territory. Requirement L3 does not apply to a building which is a relevant building for the purposes of regulation 7(4) of the Building Regulations 2010⁶, which is how listed and protected buildings are handled where compliance would unacceptably alter their character.

The direction of travel is set. The Future Homes and Buildings Standards will be implemented via the Building Regulations etc. (Amendment) (England) Regulations 2026⁹, tightening what new homes must achieve; we cover that separately in the Future Homes Standard.

Who bears responsibility for non compliant work

Responsibility runs on two tracks. On one track, the people responsible for building work, including agents, designers, builders or installers, must ensure that the work complies with all applicable Building Regulations requirements¹¹. If you are employing a builder, the responsibility will usually be theirs, but this should be confirmed at the very beginning of the project¹⁷. The Welsh guidance says the same¹⁸.

On the other track sits the owner. 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 regulations¹⁶. The Welsh guidance repeats this¹⁸. In Scotland, the duty to comply lies with the owner, or in some cases the client, for the work¹⁴. The practical reading is that a builder's responsibility is real but contractual and professional; the owner's exposure is statutory and attaches to the building, surviving the builder's departure from the scene.

There are also specific notice duties on the person carrying out the work. Under regulation 7A, which applies where a building is erected in England and Wales, the person carrying out the building work must give the local authority notice to that effect²⁶. The person doing the work could be prosecuted and fined if they do not comply with building regulations². For a household, the lesson is to settle who is handling approval in writing before work starts, because an enforcement notice lands on the owner regardless of who cut the corners.

Certificates, enforcement and work done without approval

The Building Regulations 2010 define unauthorised building work in regulation 18: 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 specified²⁷. The Wales version of the regulation is materially the same²⁷. In plain terms, work that needed a route into the system and never took one is unauthorised.

The consequences are financial and practical. You may have to correct the work or pay a fine if building regulations are not followed⁵. If building regulations approval is not given, then the work should be changed so it meets standards²⁰. The person doing the work could be prosecuted and fined². Beyond the immediate penalty, unauthorised work leaves no certificate, and certificates matter later: nothing in Part 2 of the Energy Performance of Buildings Regulations requires an energy performance certificate to be given or made available to a prospective buyer or tenant before construction of the building has been completed²⁵, which is one example of how completion and certification unlock the paperwork of selling or letting.

The certificate itself is issued at the end. Once the building control body has decided that the work meets all the Building Regulations requirements, it will issue a Building Regulations completion certificate if it is a building control authority, or a final certificate if it is a registered building control approver⁶. The Welsh guidance describes the same split for heat pump installation work¹¹. Where electrical works are involved, an Electrical Installation Certificate signed by a competent person must be provided, and until that certificate is received a Completion Certificate for the whole of the works cannot be issued²¹. In Scotland, the equivalent step is the owner or client certifying on completion that the works have been constructed in accordance with the building warrant and the building regulations¹⁴.

How extensions, glazing, conservatories and solar affect existing homes

Existing homes meet the regulations differently from new builds, and the common projects each have their own pattern.

Extensions. Building regulations will generally apply if you want to build an extension to your home²⁸. There is no floor-area threshold for an extension in the way there is for a conservatory: the extension is building work under regulation 3 from the outset¹⁶.

Conservatories. Conservatories are normally exempt from building regulations when they are built at ground level, single storey, and less than 30 square metres in floor area; separated from the house by external quality walls, doors or windows; and heated by an independent heating system with separate temperature and on/off controls. The glazing and any fixed electrical installations must comply with the applicable building regulations requirements⁷. The Welsh guidance states the same conditions²⁸. The trap is the junction: any new structural opening between the conservatory and the existing house will require building regulations approval even if the conservatory itself is an exempt structure⁷.

Windows and glazing. Replacing windows and doors is work covered by building regulations approval². Planning permission is a separate question with its own rules: for flats and maisonettes, replacement windows do not require planning permission so long as they are identical like-for-like replacements in appearance and material, but permission is likely if the new windows would not match the existing appearance, material or glazing type, including a change between single and double or triple glazing; and for a listed dwelling house, planning permission would be required for replacement windows²⁹.

Roofs. Work to the roof of a house, such as re-roofing, that does not materially affect its external appearance will usually not require planning permission³⁰. That is a planning statement, not a building regulations one: structural work to a roof is an alteration and falls to be assessed under regulation 3.

Solar panels. Installing solar panels may require approval under the Building Regulations, because of the associated electrical works³². Building regulations will normally apply to installing solar panels on your roof³³, and a building regulations application is needed when installing a solar panel on a roof, with the roof strength assessed and possibly strengthened³⁴. Planning is again separate: placing solar panels on the roof of a house or flat, or on a building within its grounds, is considered in most cases permitted development under the 2015 Order, Schedule 2, Part 14, Class J³³, and installation on residential buildings may be permitted development with no need to apply for planning permission³⁵. But solar panels on listed buildings need planning permission and listed building consent³⁴, and listed building consent is needed before work can commence³². We cover the planning side in permitted development rights and listed buildings.

The impact on a household's independence

The building regulations are one of the few levers the state holds over how far a home can go energy-independent, and they cut both ways. On the one hand, they are a condition on almost every step towards self-sufficiency: solar panels on a roof, a new heating appliance, cavity wall insulation, replacement glazing and hot water cylinders are all building work or controlled fittings¹⁶, and each needs either a building control application or a registered installer's self-certification⁵. A household cannot quietly re-engineer its own home outside the system.

On the other hand, the system is designed to be passable. The competent person route means a registered installer of windows, boilers or electrical work self-certifies, and no separate approval is needed⁵. Minor work, including most repairs and additions to existing circuits outside kitchens, bathrooms and outdoors, needs no notification at all²³. The exemptions cover genuinely small structures, from conservatories under 30 square metres to stand-alone buildings under 50 square metres²⁸.

The dependence that remains is on the inspection and certification chain: a building control body or a scheme-registered installer, and ultimately the local authority that can serve an enforcement notice on the owner¹⁶. The certificate at the end is the household's proof of compliance, needed for the sale or letting of the property and unobtainable while an Electrical Installation Certificate is outstanding²¹. The rules also move: the 2021 amendments changed the guidance⁸, the 2026 regulations will implement the Future Homes and Buildings Standards⁹, and a project is judged by the rules in force when it is approved. A household planning energy work does well to check the current position before starting, not after.