Can I build a loft conversion on the Party Wall?

This is a question our clients often ask if they are planning to construct a loft conversion.

Let’s find the answer.

If you live in a semi-detached or terraced house, you would have a shared party wall(s). You can build a loft up to the centre of the party wall and have the right to overhang roof tiles on the side of a dormer, overhanging the line of junction of the party wall.

For a typical loft conversion, dormer on the rear or side of the house will be incorporated. Moreover, it also involves the insertion of some structural steelwork to support both the dormer and the new floor.

Now the question is: Where the steelwork spans when doing a loft conversion?

In a semi-detached house, the steelwork distance from the flank wall to the party wall. Whereas, in a terraced house, it spans from party wall to party wall.

The work will require you to cut pockets into the party wall, insert a spreader plate, and set the steel beam in. However, you will require building regulation approval before starting the work.

Another question arises: Does Party Wall etc Act grant a right for the loft conversion?

The short answer: Yes, it does.

Section 2 of the Party Wall Act grants a right to insert structural beams Into the party wall.

However, you may require a Party Wall Agreement to build a loft conversion. You are required to serve valid party wall notices on to all adjoining owner/s.

Even if the dormer isn’t built on the party wall, you will still have to serve a Party Wall Act Notice to affected adjoining owners. However, if your neighbour has already raised the party wall for a dormer, then the Party Wall Act allows you to use the same wall as a part of your building’s structure. You will need a Party Wall Notice for this as well.

You may also have to compensate your neighbour for using the wall to reflect the cost savings that you may have made.

What happens after I serve the Party Wall Notice?

Your neighbour has three options after they receive a notice.

  1. Give written consent
  2. Dissent to the notice
  3. Do nothing (default dissent)

If your neighbour dissents to the notice or fails to respond after 14 days of serving the notice, you will need to appoint a Party Wall Surveyor to draw a Party Wall Award.

Want to build your loft conversion on the Party Wall? Looking for a Party Wall Surveyor in London? Contact Seven One Associates to get help and support on how the works will be affected by the Party Wall Act.