What Happens If You Build Without Planning Permission?

The risks and consequences of carrying out development without the required planning permission, and how to regularise unauthorised work.

Building without the required planning permission is not a criminal offence in most cases, but it can have serious consequences for you and your property. Understanding the risks helps you make informed decisions about your project.

What Is Unauthorised Development?

Unauthorised development is any building work or change of use that required planning permission but was carried out without it. This includes:

• Extensions that exceed permitted development limits
• New buildings constructed without approval
• Changes of use (e.g. running a business from a residential property)
• Work on listed buildings without listed building consent
• Breaching conditions attached to a previous planning permission

How Councils Respond

When a council becomes aware of potential unauthorised development - usually through a complaint from a neighbour - they will investigate. The planning enforcement team has several options:

No Action

If the council considers the development acceptable and would have granted permission if applied for, they may decide to take no enforcement action. However, this does not regularise the work - you still lack formal approval.

Enforcement Notice

The council can issue an enforcement notice requiring you to:

• Remove the unauthorised development entirely
• Modify it to make it acceptable
• Stop an unauthorised use

You typically have 28 days to appeal an enforcement notice to the Planning Inspectorate. Failing to comply with an enforcement notice is a criminal offence and can result in prosecution and fines.

Breach of Condition Notice

If you have planning permission but are not complying with its conditions, the council can issue a breach of condition notice. There is no right of appeal against this type of notice.

Stop Notice

In urgent cases, the council can issue a stop notice alongside an enforcement notice, requiring work to cease immediately. Ignoring a stop notice is a criminal offence.

Time Limits for Enforcement

There are time limits after which the council can no longer take enforcement action:

• 4 years for building work and change of use to a single dwelling
• 10 years for other changes of use and breaches of conditions

After these periods, the development becomes immune from enforcement. You can apply for a Lawful Development Certificate to formally confirm this status.

How It Affects Selling Your Property

Unauthorised development causes significant problems when selling:

• Conveyancing solicitors will flag it during searches
• Mortgage lenders may refuse to lend on the property
• Buyers may pull out or demand a reduced price
• Indemnity insurance may cover some situations but is not a substitute for proper approval

How to Regularise Unauthorised Work

If you discover that work on your property was done without permission, you have several options:

1. Retrospective planning application - apply for planning permission for the work already carried out (same fee as a normal application)
2. Lawful Development Certificate - if the work was done more than 4 years ago, apply for a certificate confirming it is now lawful
3. Negotiate with the council - discuss whether modifications would make the development acceptable

The best approach is always to check whether you need planning permission before you start building. It is far cheaper and less stressful than dealing with enforcement action after the fact.