top of page
  • Belfrage Surveying Services

Minimising the risk of party wall damage during loft conversion works

Loft conversion works

Many homeowners, faced with the high cost of purchasing a larger property and the inconvenience of moving, see the conversion of their loft space as an attractive option to gain additional living space. However, this endeavour is not without its risks, particularly concerning potential damage to party walls - the wall shared with a neighbouring property. In this article, we explore the risks associated with loft conversions and outline measures to minimize these risks.

The likelihood of damage occurring during a loft conversion hinges on several factors, including the strength and condition of the party wall and neighbouring building. Additionally, the thoroughness of the design, planning and execution by the structural design and contractor teams plays a crucial role in safeguarding against potential issues. Most loft conversion projects involve the insertion of steel beams into party walls to support additional loads. Careful consideration must be given to this process, as cutting pockets into the party wall to insert these beams can lead to unintended damage occurring. In the worst case while forming the pockets for the beams, a hole (or holes) could be punched through the wall, along with the inconvenience that comes with this.

Special attention is required when dealing with older properties, especially those constructed before 1945, as their party walls may consist of lower-quality brickwork held together by weak or perished mortar. When undertaking to cut pockets into the party wall, only using hand tools or circular cutting disk tools is essential to minimise the risk of excessive brickwork displacement and potential damage on the neighbour’s side. Percussive tools should not be used to prevent damage occurring. Belfrage Surveying Services would not agree to any Award where these requirements are not met.

Roof coverings are often replaced during loft conversions, and this presents its own set of challenges. In cases where there are no parapet walls separating attached properties, careful consideration must be given to the junction between new and existing roof tiles at the party wall line. Typically this will be dealt with by installing a bonding gutter. Without proper weathering, leaks can occur, causing damage to the neighbour’s side. Gutters can also become blocked with building debris and should be checked before scaffold is removed.

A common loft conversion involves constructing a full-width dormer or mansard roof extension where neighbouring properties are separated with parapet walls. Parapet walls are extensions of the party wall above roof level and they act as a firebreak between properties. When undertaking loft extension projects, it's crucial to consider issues such as exposing the party wall, protecting the neighbouring property from debris, and maintaining the structural integrity of the party wall.

As well as other considerations, when drafting and agreeing an Award for a loft conversion, Belfrage Surveying Services will consider the following,

  • Exposing the party structure requires measures to prevent dampness bridging into the neighbouring property, such as using suitable tarpaulins against the party wall during roof covering removal.

  • Protecting the neighbouring property involves the installation of protective netting on scaffolding structures and placing polystyrene or hardboards on neighbouring roof areas to prevent damage where debris or objects fall.

  • Maintaining the structural integrity of the party wall is critical, especially when projecting chimney breasts are removed. Adequate support for chimney stacks must be outlined in the structural engineer's design. The removal of projecting chimney breasts and raising of chimney stacks also necessitate precautions to prevent soot and building dust from falling into the neighbour’s chimney and causing damage to carpets, soft furnishings and gas appliances.

Beyond physical risks, loft conversions involve legal considerations. When initiating the process of the Party Wall etc. Act 1996, it's important not to assume that the neighbour will consent to the works proposed in a party wall Notice. Formal written agreements, known as party wall Awards, may be necessary. If a notice is dissented to or disagreements arise, the appointment of surveyors becomes essential to settle the matters diligently and thoroughly while protecting the interests of both the building owner and the adjoining owner.

In conclusion, while loft conversions offer a practical solution for homeowners seeking additional space, it's crucial to be aware of the potential risks and take proactive measures to mitigate them. By addressing structural, construction, and legal considerations early in the design process, homeowners can embark on loft conversion projects with confidence and minimise the likelihood of disputes with neighbours.

We would be happy to discuss any queries you may have in respect of your project, or your neighbour’s project, at no charge. Contact us here.

Recent Posts

See All

What is a Party Wall Award and do I need one?

When Party Wall notices are served on adjoining owners, they can choose to consent to the works, dissent and appoint their surveyor, or take no action, leading to deemed dissent and an appointed surve


bottom of page