Building control is the regulatory system in England and Wales that checks construction work meets the minimum standards set by the Building Regulations 2010 and the Building Act 1984, covering structural safety, fire protection, energy efficiency, drainage, and accessibility. You need it for most work that affects a building’s structure, fire safety, or key services, which includes extensions, loft conversions, removing load-bearing walls, new boilers, rewiring, and significant drainage changes. The system is enforced by either your local authority building control team or a registered private approver, and for the tallest residential buildings by the Building Safety Regulator.
What Work Needs Building Control Approval
The common thread across projects that need approval is simple: if the work could create a hidden danger when done badly, it falls within scope. Removing or altering a load-bearing wall, adding an extension, converting a loft into a habitable room, and underpinning foundations all qualify. So does replacing a roof, installing a new boiler or wood-burning stove, rewiring electrical circuits, and making significant changes to drainage.
Approval is a legal requirement, not a formality. The regulations set performance standards the finished work must meet, and the building control process is how compliance is checked and recorded. Without that check, there is nothing to prove the work was done correctly, and that absence has real consequences later when you try to sell, remortgage, or insure the property.
What’s Exempt and What Self-Certifies
Some smaller projects are exempt from the formal application requirement. A ground-floor porch under 30 square metres with appropriate glazing does not need building control sign-off in most circumstances. The same is true for some detached garages, carports, and conservatories that meet strict size and glazing limits set out in the regulations. These exemptions exist because the structural risk is low, but misjudging whether a specific project qualifies is one of the most common ways people end up with unauthorised work on their property. Confirm the exemption applies before relying on it.
A separate shortcut exists through competent person schemes. Registered installers in specific trades, including gas engineers, electricians, and window fitters, can self-certify that eligible work complies with the Building Regulations and notify the local authority directly. If you hire someone registered under such a scheme, you should receive a certificate of compliance rather than a standard completion certificate. Keep that certificate: it serves the same evidential purpose when you come to sell.
How Building Control Differs From Planning Permission
Building control and planning permission are separate systems that regulate different things, and treating them as interchangeable is a mistake that leaves owners exposed on one side even when they’ve ticked the box on the other.
Planning permission governs how land and buildings are used: whether you can build an extension at all, how tall it can be, how close it sits to a boundary, and whether the design fits the local area. Building control governs how the work is physically constructed once it has the green light. It checks that foundations are deep enough, the structure can carry the loads imposed on it, fire escape routes work, and insulation meets current thermal standards.
You can need one without the other, both, or neither. A loft conversion that falls within permitted development rights might not need planning permission, but it will almost certainly need building control approval because it involves structural alterations and changes to means of escape. A change of use for a commercial property might need planning permission but trigger no Building Regulations work at all.
Who Signs Off the Work
For standard projects, you choose between two types of building control body. The first is your local authority building control team. The second is a registered building control approver, formerly called an approved inspector, which is a private sector firm performing the same statutory functions.1LABC. About LABC
Both apply the same Building Regulations, so the legal standards your project must meet are identical regardless of which route you pick. The differences are practical: fee structures, turnaround times, and style of communication. Private approvers sometimes offer faster turnaround and a single named contact, which suits developers running to tight schedules. Local authority teams bring deep knowledge of local ground conditions and existing building stock, which can matter for older properties or complex sites.
If you choose a private approver, they must submit an initial notice to the local authority before work begins. The council has a fixed period to accept or reject it, and work should not start until the notice is accepted.
Higher-Risk Buildings and the Building Safety Regulator
The Building Safety Act 2022 created the Building Safety Regulator within the Health and Safety Executive. For higher-risk buildings, meaning residential buildings of seven storeys or more (or 18 metres or more in height), plus care homes and hospitals meeting that same height threshold during design and construction, the BSR acts as the building control authority directly. Developers of these buildings cannot choose a local authority or private inspector. Instead, the BSR runs a permissioning system with hard stop decision points at key stages, and dutyholders must demonstrate compliance before authorisation to proceed is given.2GOV.UK. Building Safety Regulator Approach to Enforcement Factsheet
The BSR also oversees the performance of all building control bodies and the registration of individual inspectors, who can be suspended or removed for misconduct or poor performance. For ordinary residential projects, that means the professionals you deal with are held to a unified set of competence standards backed by a national regulator.2GOV.UK. Building Safety Regulator Approach to Enforcement Factsheet
How to Apply: Full Plans or Building Notice
There are two main routes for applying, and choosing the wrong one can cause avoidable delays. Applications can go through the Planning Portal or directly to your chosen building control body.3Planning Portal. Planning Permission and Building Regulations Approval
A Full Plans application is the thorough route. You submit detailed architectural drawings, structural calculations from a qualified engineer where load-bearing elements are involved, and site location plans showing the plot’s relationship to neighbouring infrastructure, drains, and boundaries. The building control body reviews everything against the regulations before construction starts and issues an approval, a conditional approval with modifications required, or a rejection. The advantage is certainty: you know before you break ground whether the design complies.
A Building Notice is a lighter route suited to straightforward domestic work. You notify the building control body of your intention to start and provide basic project details, but you do not submit detailed plans for prior approval. The inspector checks compliance during site visits as the work progresses. The risk is that if something doesn’t comply, you may have to tear it out and redo it at your own expense. For anything structurally complex, Full Plans is the safer choice even if it takes longer.
Fees vary by project type and scale. Most building control bodies publish fee schedules with separate charges for plan checking and site inspections, and the total cost scales with complexity. A simple window replacement costs far less to process than a two-storey rear extension with steelwork.
Inspections and the Completion Certificate
Once work begins, you must notify your building control body at specific stages so an inspector can check compliance before the next phase covers up what came before. The typical sequence starts with a commencement notice, then inspections at foundation excavation, when concrete is poured, when below-ground drainage is laid, and during construction of the structural frame or walls. Later visits cover insulation and energy performance, fire stopping between compartments, and the installation of services.
The foundation inspection is the one that matters most in practical terms. Once concrete is poured, nobody can see what’s underneath without destructive investigation. If the trench depth, width, or ground bearing capacity doesn’t meet the structural engineer’s design, the issue can be corrected cheaply at this point. Six months later, after a building sits on top of it, the cost of fixing the same problem multiplies enormously.
A final inspection takes place once the work is finished, and if everything complies the building control body issues a completion certificate. This certificate is the definitive proof that the work met the Building Regulations as they applied at the time of construction. Mortgage lenders and insurers routinely ask for it, and its absence can derail a property sale years after the work was done.
What Happens If You Skip It
Building without approval, or building in a way that breaches the regulations, triggers a chain of consequences that grows more expensive the longer it goes unresolved. Under Section 36 of the Building Act 1984, a local authority can serve an enforcement notice requiring the owner to pull down or alter non-compliant work, which can mean demolition of an entire extension if no reasonable modification brings it into compliance.4Legislation.gov.uk. Building Act 1984
Breaching the Building Regulations is also a criminal offence under Section 35 of the Act. The local authority can prosecute the person who carried out the work or, in some circumstances, the building owner. For offences committed on or after 13 March 2015, conviction carries an unlimited fine, with the court assessing the amount based on the severity of the breach, the risk created, and the offender’s means.4Legislation.gov.uk. Building Act 1984
The financial pain doesn’t end with fines. Without a completion certificate, selling or remortgaging becomes extremely difficult. Conveyancing solicitors flag the absence of building control sign-off as a defect in title, and mortgage lenders are reluctant to lend against a property with unauthorised structural work. Insurers may also refuse to cover damage connected to unpermitted work, leaving the homeowner fully exposed if something goes wrong.
Fixing Unauthorised Work: Regularisation
If building work was completed without proper approval, the local authority can consider a regularisation application. This is a retrospective review of work that should have been approved at the time but wasn’t, and it is only available through the local authority building control team, not through a private approver.
The process is more invasive and more expensive than a standard application. Because the inspector couldn’t visit during construction, they need to verify compliance after the fact. That often means opening up finished walls, floors, or ceilings to expose structural connections, insulation, wiring, and plumbing. If the inspector finds elements that don’t meet the regulations, you’ll need to carry out remedial work before a regularisation certificate can be issued. In the worst cases, this means stripping a room back to its frame.
There is no guarantee of approval. If the work is fundamentally non-compliant and cannot be brought up to standard without disproportionate cost, you may be left in a worse position than before you applied, because the local authority now has formal knowledge of the breach. Getting professional advice before submitting a regularisation application is worth the upfront cost. The alternative, leaving unauthorised work undisclosed and hoping it never surfaces, tends to fail at the worst possible moment: during a sale, a remortgage, or an insurance claim.