Flats and the Party Wall Act – Who is an ‘Owner’?

Section 20 of the Act defines an owner, amongst other things, as ‘a person in possession of land, otherwise than as a mortgagee or as a tenant from year to year or for a lesser term or as a tenant at will’. As it makes no distinction between the various types of ‘ownership’ (only that the remaining term must be greater than 12 months) it means an owner proposing works that affect an adjoining property may have to notify the freeholder as well as the leaseholders of any flats within the building.

When preparing notices, the building owner must first establish which owners are affected and to do that it is necessary to know the demise of any flats within the adjoining property. Sometimes this is obvious, such as with a converted house where there is a flat on each level, but that not always the case and purpose-built blocks generally have multiple flats on each level. If the layout of the adjoining property cannot be accurately established, I’d suggest only notifying the freeholder initially and asking them about the layout when they respond (this may also help to manage the number of surveyors involved but elongates the process so plan early).

Where a house has been converted into flats it’s common for the leaseholders to jointly own the freehold of the building (in this scenario, the freehold company will often be named after the address e.g. ‘21 Acacia Avenue Limited’). The joint freeholders will still have an individual lease and must therefore be notified in both capacities (as above, I’d recommend notifying the freehold company first).

The details of freeholders and long leaseholders (in excess of 7 years) are held on the Land Registry database and can be downloaded for a small charge.

Until recently, a shorthold tenant could have met the Act’s definition of ‘Owner’ if their remaining term was in excess of 12 months. However, the Renters’ Rights Act (which came in to force on 1st May 2026) made all assured shorthold tenancies ‘periodic’ (including existing tenancies). Tenants still enjoy a range of rights as ‘occupiers’ under the Act, including the right to be compensated for any loss or damage incurred.

Once the layout and ownership details have been established, the next step for the building owner is to work out which aspects of the proposed work are notifiable to which owners. We’ll cover that in the next couple of posts in this short series.

If you require advice on a party wall matter, you are welcome to contact us on 020 7183 2578 or via email.