Buying a home with an extension? What you need to check

Was planning permission obtained? Do the improvements comply with building regulations? Even if permissions are missing, there is a solution.

Rear extension

Enforcement notices

Local authorities can serve enforcement notices against any property owner for breaches of the law. An example of a breach would be an extension that does not have suitable planning consents or building regulations.

An enforcement notice might require the extension to be modified or even demolished. You could be fined or even imprisoned if you fail to address the breach – even if you were not the property owner at the time the work was carried out.

As a buyer, you would inherit the liability for the breach.

What is Permitted Development?

Some extensions don't require full planning permission and can be built in accordance with Permitted Development (PD) rights. All extensions will need Building Regulations consent, however.

Permitted Development is a term given to works which, although they may technically require planning permission, are deemed to have permission granted under a general permitted development order.

Generally, this means a property may be extended to the rear or side without planning permission, providing the extension meets certain criteria.

These criteria specify that the extension must not exceed 15% of the original volume or the property or 10% if the house is part of a terrace. The extension must not extend too far from the original property and shouldn't occupy more than 50% of the garden area.

The exact legislation is detailed in the Town and Country Planning (General Permitted Development) Order 1995 as amended by the Town and Country Planning (General Permitted Development) (Amendment) (No. 2) (England) Order 2008.

Planning permission is required when:

The proposed extension is:

  • Greater in volume than 115 cubic metres
  • Higher than the original roof height
  • Extends beyond the dimensions allowed for permitted development – for example 3m from the original property for a 2 storey extension
  • If a property has already been extended and a new extension exceeds the 15% (or 10% for a terrace) limit.
  • The property is a listed building or in a conservation area

Building Regulations

Ensuring that building work complies with Building Regulations is usually the responsibility of the builder employed to complete the project. However, the property owner is ultimately the person who would receive an enforcement notice if the work is not compliant.

A Building Regulations Compliance Certificate should be issued to the property owner and the local authority should be notified that the work has been carried out in accordance with the regulations.

How might a property owner have breached planning regulations?

A home-owner may unwittingly overstep the Permitted Development rights and build something without obtaining planning permission.

For example, if the owner believed permission was not needed for a conservatory, but the owner didn't consider the conservatory's overall dimensions, there may be a breach of the regulations.

Another common example is when a loft has been converted into an extra bedroom without Building Regulations approval.

Often these issues only come to light when the owner decides to sell.

What should a prospective buyer consider?

Firstly, has the house been extended at all? This may not be obvious as some houses are built with conservatories or attic bedrooms. If the property has been extended, is the extension within the Permitted Development rules?:

  • Does the extension seem particularly large or take up a significant part of the garden?
  • Does the extension encroach on the neighbouring boundary?
  • Do the dormer windows seem higher or wider than the existing roof line?

Ask the owner if there is any evidence to support the work that has been done. This evidence could be the details of the approved planning permission.

Alternatively, the evidence could be a Lawful Development Certificate, which can be provided by the local authority on request to prove the extension meets planning control requirements as a Permitted Development. If the owner is unable to produce any documentation, ask when the work was completed.

If it was more than 4 years ago and the local authority has not taken any action for breach of planning regulations, it will not now be able to do so.

Peace of mind with indemnity insurance

Where the extension was added in the last 4 years the property owner may risk being served with an enforcement notice.

Ask if there has been any discussion with the local authority with regard to the work. If there has been no discussion for at least the previous 3 months it may be possible for the home-owner to obtain a legal indemnity insurance policy to provide cover against the risk of legal action being taken for a breach of planning regulations.

The owner will need to confirm that the house has been used for residential purposes for at least the last 12 months and that the work was completed more than 12 months ago. If there are no certificates of completion to show the work met Building Regulations further indemnity insurance can be bought to cover this.

Legal indemnity insurance provides cover for the life of the property and is automatically transferred to each new owner of that property. However, the policy would be invalidated if the home-owner were to contact the local authority about the property.

Your next step

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Gaynor Haliday, Legal researcher

Author:
Gaynor Haliday, Legal researcher