Permitted Development When Buying a Home: What Should You Check Before Exchange?

If a home has been extended, converted or altered, “permitted development” may explain why there is no full planning permission on file. Before exchange, buyers should still establish what work was carried out, ask their solicitor or conveyancer to verify the planning and building regulations position, and use the survey to understand the visible condition of the alteration. A surveyor can flag defects and matters for legal follow-up, but cannot confirm from a visual inspection alone that historic works were lawful.

It is common to view a property and discover that it has been extended, had a loft converted or undergone other significant alterations. If the seller says the work was carried out under permitted development rights, what should you actually check as the buyer?

Planning status and physical condition are two different parts of the same due-diligence process. Your survey helps you understand what appears to have changed and whether the work shows visible defects or risks. Your solicitor or conveyancer deals with the legal and documentary checks around permissions, approvals and certificates.

What is permitted development?

In England, permitted development rights are a national grant of planning permission allowing certain building work and changes without a full planning application, provided the relevant limits and conditions are met. Some rights still require prior approval from the local planning authority. You can read the Government guidance on when planning permission is required for the current framework.

Permitted development rights are not universal. Householder rights mainly apply to houses rather than flats, and may be restricted by planning conditions, Article 4 directions or the property’s location and status, including designated areas.

For a buyer, the absence of a full planning application is not automatically a problem. Equally, “permitted development” is not proof that no further checks are needed.

Why does permitted development matter when you are buying a home?

When buying an altered property, the important questions are whether the existing work was properly authorised, whether it appears to have been constructed satisfactorily, and whether any condition or legal issues need resolving before you take ownership.

This matters before exchange because the purchase becomes legally binding at exchange of contracts. Ideally, survey findings, legal searches and enquiries about alterations should be resolved before you commit.

What can a surveyor tell you about an extension or alteration?

A home survey is a physical inspection of the property. Where a home has been extended or altered, a surveyor can assess how the visible changes relate to the condition of the building and whether further investigation is needed.

• Identify visible evidence of extensions, loft conversions, removed walls and other significant alterations.
• Assess accessible junctions between the original building and later work for signs such as cracking, dampness, poor weathering details or movement.
• Comment on the visible quality and condition of the alteration, within the scope and limitations of the survey.
• Flag features that may have legal implications and should be raised with your solicitor or conveyancer.
• Recommend further investigation where a structural engineer, drainage specialist, electrician or other specialist may be needed.

If you are buying a property that has been significantly altered or extended, a RICS Level 3 Building Survey is often the more appropriate level of inspection because it provides a more detailed assessment and is suited to substantially altered or extended properties. Our Which Survey? guide explains the difference between the survey levels. You may also find our guide to common issues a Building Survey can uncover useful when considering defects that could affect a purchase.

What can a surveyor not confirm?

A surveyor cannot confirm the legal status of historic work simply by looking at it. The position can depend on when the work was carried out, the specific property, previous permissions and local restrictions.

Your solicitor or conveyancer should deal with the documentary and legal checks. These may include whether:

• full planning permission was required and, if so, whether it was granted;
• the work required prior approval under a permitted development right;
• a Lawful Development Certificate exists or would be relevant;
• permitted development rights had been removed or restricted for the property;
• listed building consent or another separate consent was required;
• building regulations approval, completion documentation or competent-person certificates are available; and
• the works raise any title, covenant, lease or other legal issues.

What should you check before exchange?

If you are buying a home with an extension, conversion or major alteration, use the following checks before exchange.

1. Establish what work was carried out and when

Ask your solicitor or conveyancer to establish what was altered and when. Useful documents may include plans, planning decisions, prior approval notices, building control documents, structural calculations, warranties and certificates. The date matters because the applicable rules and property history may affect the position.

2. Ask your conveyancer to verify the planning position

Do not rely on the seller simply saying an extension was “permitted development”. Your conveyancer should review the planning history, searches and available documents, raise enquiries and advise what further evidence is needed.

3. Check building regulations separately

Planning permission and building regulations are separate systems. Work may be permitted development for planning purposes and still require building regulations approval. Ask your conveyancer to confirm what building control paperwork is available for extensions and structural alterations.

4. Compare the paperwork with what is actually at the property

Check that certificates and drawings actually relate to what was built. If the survey identifies an alteration that does not appear to match the information supplied, raise the discrepancy before exchange.

5. Follow up the survey recommendations

If the survey identifies cracking, inadequate support, poor roof junctions, dampness, drainage issues or other concerns, obtain any specialist advice or quotations recommended while you can still investigate or negotiate.

6. Resolve missing documents with your conveyancer before contacting the council yourself

Missing paperwork does not automatically mean you should walk away. Depending on the work, your conveyancer may discuss further evidence, a lawful development certificate, building control regularisation or indemnity insurance. Take legal advice before contacting the local authority yourself, as this can affect the options available in some transactions.

Does permitted development mean there should be no paperwork?

No. Some permitted development can proceed without a planning application, while other rights involve prior approval. A Lawful Development Certificate can formally confirm that existing or proposed development is lawful for planning purposes. Separate building regulations approvals and certificates may also be required.

If you want to understand the distinction between planning and building control in more detail, the Government building regulations guidance explains when approval may be required and why it is separate from planning permission.

What if the seller says, “It was all permitted development”?

Treat that as useful information, but not the end of the enquiry. Ask what was done, when it was completed, what planning route applied, what building control documents exist and whether the survey raises concerns about the work.

Legal verification and physical inspection together are more useful than trying to decide whether an extension simply “looks” like permitted development.

Get a clear picture before you commit

Alterations and extensions are not necessarily a reason to avoid a property. They add another layer of due diligence. The aim is to understand both the condition of the work and the paperwork behind it before exchange.

At h&s Surveyors, we take a personal approach. We will speak to you before the inspection about any concerns, and once you receive the report you can come back to us with questions or points raised by your solicitor or a contractor.

If you are considering an altered or extended property in Devon and would like advice on the most appropriate survey, get a free, no-obligation quote or speak to our team before you exchange.

Note: This article relates to property in England and provides general information only. Planning and legal requirements depend on the individual property and circumstances, so buyers should take advice from their solicitor, conveyancer and other relevant professionals where required.