Can You Occupy a Building Without Building Control Sign Off

Building control sign off confirms that construction or renovation work complies with UK building regulations. It is the final step in a process that includes inspections at key stages and ends with the issue of a completion certificate. But what happens if that certificate hasn’t been issued yet? Can you still move in or start using the building?

In short, no — you are not supposed to occupy a building that hasn’t been signed off by building control, especially if it’s a new build or a major renovation. Doing so can carry serious risks and legal consequences, and may compromise the safety of the people living or working in the building.

Why Building Control Sign Off Matters

Building control sign off means that an approved inspector or local authority has inspected the work and confirmed that it complies with regulations. These rules cover everything from structural safety and fire resistance to ventilation, insulation, and accessibility. Without formal sign off, there’s no official evidence that the building is safe or fit for use.

This is particularly important in new dwellings, flats, commercial spaces, or any premises where people will sleep, work, or spend significant time. Sign off protects not just the occupier but also future buyers, tenants, insurers, and mortgage lenders.

Legal Restrictions on Occupation

In many cases, occupying a building without completion approval is a breach of the Building Act 1984. Local authorities have the power to take enforcement action if a building is used before it has been properly inspected and approved. They can issue a notice preventing occupation, or require you to vacate the premises until all outstanding issues are resolved.

For new residential properties, the building must also be signed off before it can be registered for council tax, sold, or legally let out. In commercial settings, using the space without approval could breach health and safety laws and invalidate business insurance.

Practical Risks of Occupying Early

Even if the building appears finished, occupying it without sign off can expose you to serious risk. Issues such as faulty wiring, inadequate fire safety measures, poor drainage, or structural weaknesses may not be visible — but can have dangerous consequences.

If you're living in the property and something goes wrong, you may find that your home insurance won’t cover the damage, or that you are personally liable. For developers or landlords, early occupation can result in costly claims, regulatory penalties, or delays in securing finance or tenant agreements.

Completion Certificate vs. Temporary Use

In some cases, you can apply for a temporary certificate or partial sign off, especially in phased developments or where delays are beyond your control. This allows you to occupy part of a building under strict conditions, while final work continues elsewhere. This must be agreed in advance with the building control body and is usually limited in scope.

You’ll need to show that all life safety elements — such as fire protection, emergency exits, and structural stability — are fully complete and compliant in the area you wish to occupy.

What to Do If You’ve Already Moved In

If you’ve already occupied a property without completion sign off, you should contact building control immediately. An inspector will need to assess the work and determine whether it meets current standards. If parts of the building are concealed — such as insulation, foundations, or hidden wiring — they may ask for them to be exposed for inspection.

If everything is found to be in order, you may still receive a completion certificate. If not, remedial work may be required. In some cases, you will need to apply for retrospective approval through a regularisation certificate, though this is only available for work completed after 1985.

Occupation Without Sign-Off in New Builds

In new-build homes, occupation without a completion certificate is especially problematic. Mortgage lenders and conveyancers often won’t release funds or allow legal completion of a property purchase unless a valid certificate is in place. Even if the buyer is willing to move in, the lender won’t permit it — meaning the deal can stall entirely.

Builders or developers who allow buyers to move in before formal sign-off risk breaching warranties or new-home guarantees such as NHBC or LABC. These organisations require confirmation that building control approval has been granted as a condition of cover.

Partial Occupation in Multi-Unit Buildings

For developments such as blocks of flats or student housing, it’s sometimes possible to obtain a partial completion certificate or interim approval for certain areas of the building. This allows part of the property to be occupied while work continues elsewhere — but only if all essential safety systems are fully operational.

This option must be agreed in writing with the building control body, and it often requires extra documentation, risk assessments, and ongoing inspections. It is not guaranteed and cannot be assumed without formal authorisation.

Impacts on Commercial Properties

In commercial or industrial settings, occupying a building without sign-off can lead to additional complications beyond local authority enforcement. The business may be in breach of fire safety legislation, employer liability rules, and health and safety at work regulations.

Commercial insurance policies often have strict requirements for regulatory compliance. If an incident occurs in a building without final approval, the insurer may refuse to pay out, or even cancel cover altogether.

Local authorities may also deny licences or operating permits if the premises haven’t been legally signed off — this applies to restaurants, care homes, schools, gyms, and any business serving the public

Risk of Prosecution or Enforcement

Under Section 35 of the Building Act 1984, carrying out or using a building in breach of regulations can lead to prosecution in a magistrates’ court. This is rare but not unheard of — especially if the unauthorised occupation results in injury, fire, or structural failure.

More commonly, the local authority will issue a formal notice requiring compliance within a set time. If the owner ignores it, the authority can take further action, including issuing a prohibition notice or carrying out the work themselves and billing the owner.

Future Sale and Property Value

A missing completion certificate might not stop you from living in the building, but it can become a major issue when selling or refinancing. Most solicitors acting for buyers will insist on seeing a valid certificate. If you don’t have one, you may need to apply for retrospective approval, arrange indemnity insurance, or offer a reduction in the sale price.

Buyers often view this as a red flag, particularly if the work is extensive — such as extensions, loft conversions, or structural changes. Even if the work looks well finished, the absence of official sign-off casts doubt on its safety and legality.

Help &Advice

If you’re unsure whether your building has been properly signed off, you can contact your local authority building control team or the private inspector you used. They can confirm whether a certificate was issued and, if not, guide you through the next steps.

If no inspections were carried out at all, a regularisation application may be your only route — but it’s a more expensive and uncertain process than following the rules from the start.

Final Word

Occupying a building without building control sign off is not just a technicality — it’s a legal and safety issue. Without proper approval, you put people at risk, expose yourself to liability, and may invalidate insurance or property transactions. Always ensure that building control has inspected and signed off your project before anyone moves in. It’s the final step for a reason — and skipping it can have serious consequences.