New Permitted Development rules have opened up the possibility of creating thousands of new apartments on existing buildings – great news if you’re a landlord or developer looking to expand

What are the new rules on 2 storey extensions on apartment blocks?

From 1st August 2020 a new permitted development (PD) right will include 2 storey extensions on purpose-built blocks of flats. This will only apply to buildings currently over three storeys in height and the total height of the extended building cannot be greater than 30 metres, and the new accommodation must be single-floor apartments.

This new PD right applies to buildings constructed after July 1st 1948 and before March 5th 2018 and does not apply to buildings which have been converted to flats under previous permitted development rights. 

2 storey extension

As you might expect, these rules do not apply to the usual exclusions such as Conservation Areas, Listed Buildings, buildings in Areas of Outstanding Natural Beauty, Sites of Special Scientific Interest, and so on.

Any other conditions for these extensions?

The permitted development right also specifies that the new 2 storey extensions cannot extend over 7 metres from the existing roof, and that each new storey may not be greater than 3 metres in height. 

Before development starts, you must make an application for Prior Approval from your local authority, and only if it is granted can the the extension be permitted. Your local authority with make assessments such as:

  • transport and highways impacts
  • flooding risks
  • the extension’s external appearance
  • natural light provision in habitable rooms
  • amenity impact on neighbours (overlooking, privacy, loss of light).

If you’re looking for professional help in making a Prior Approval application for 2 storey extensions to an apartment block, or need assistance with these new permitted development rights, give us a call on 0121 455 0032 or drop us a message inte live chat! – we’d be delighted to help.

Why Lapworth Architects?


Our 20+ years of work mean great design and good relationships with planning departments across the region, giving  our projects the best chance to get planning permission and start building.


Your budget is tailored to your needs so you’re always on top of your costs. We’re proud to offer excellent value for money for our services, from design and planning right through to build.


Our breadth of knowledge makes us an efficient and sustainable choice of local architect, and we have a vested interest in improving our built environment right here in the West Midlands.


Wherever you are with your project, if you’re looking for honest, quality advice from professionals, chat to us, leave us a message or call us on the number at the top of the page. Let’s talk!