Do You Need a Party Wall Agreement for a Conservatory?

In some cases, you may need a party wall agreement for a conservatory project. Most conservatories involve new foundations, and if those foundations are close to a neighbouring property, the Party Wall etc. Act 1996 may apply.

The key factor is not the conservatory itself, but how close the work is to your neighbour’s structure and how deep the foundations go.

In this guide, we explain when a conservatory requires a party wall agreement, what to look out for before starting work, and when you might need a party wall surveyor. 

When Does a Conservatory Require a Party Wall Agreement?

You will usually need to serve a party wall notice if your conservatory involves:

• Excavating within 3 metres of a neighbouring structure and deeper than its foundations
• Building directly on the boundary line between properties
• Work that affects a shared wall

Most conservatories are built at the rear of the property, which means excavation is the most common trigger.

If your foundations go deeper than your neighbour’s and are within 3 metres, the Act applies.

When Does a Conservatory Not Require a Party Wall Agreement?

You may not need to serve notice if:

• The conservatory is more than 3 metres away from neighbouring structures
• The foundations are not deeper than your neighbour’s
• The work does not affect a shared wall or boundary

In detached properties with plenty of space, conservatories often fall outside the scope of the Act.

What Is the 3 Metre Rule for Conservatories?

The 3 metre rule is one of the most common triggers under the Party Wall Act.

If you excavate within 3 metres of a neighbouring building and your foundations are deeper than theirs, you must serve notice.

This applies to many conservatories because even small structures require foundations.

We explain how this rule works in more detail in our dedicated guide.

What Happens If I Build a Conservatory Without a Party Wall Agreement?

If the Act applies and you do not serve notice, your neighbour may take action.

This can include:

• Asking for the work to be paused
• Seeking legal advice
• In some cases, applying for an injunction

It may also make it more difficult to resolve any damage claims if issues arise later.

What If My Neighbour Is Building a Conservatory?

If your neighbour is building a conservatory, consider:

• How close the work is to your property
• Whether excavation is taking place near your foundations
• Whether you have received a formal notice

If the Act applies and you have not been notified, you may have rights under the legislation.

Acting early is important, especially if construction has already started.

Does a Conservatory Need Planning Permission or Building Regulations?

A conservatory may not require planning permission if it falls within permitted development limits.

However, Building Regulations approval may still be required depending on the design and how it connects to the existing property.

The Party Wall Act is separate from both planning permission and building regulations. Even if planning permission is not required, the Act may still apply.

Does a Conservatory Need a Build-Over Agreement?

A build-over agreement is different from a party wall agreement.

It relates to building near or over a public sewer and is typically required from the local water authority.

You may need both a build-over agreement and to comply with the Party Wall Act, depending on your project.

Can I Build Against My Neighbour’s Conservatory?

You cannot build directly against your neighbour’s structure without proper consideration.

If the work involves building on the boundary or affects their property, the Party Wall Act may apply.

You should also consider access, drainage and structural implications before proceeding.