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New permitted development rights for vertical extensions



New permitted development rights for vertical extensions

Base Senior Associate Joe Salt is a RIBA qualified architect, town planner and MRTPI (Member of the Royal Town Planning Institute).

In a new regular column, he takes a look at key planning issues and shares his experience and advice. This month he takes a look at how new rules allowing additional storeys to be built on existing homes under permitted development rights could help you create your dream home.

In August 2020 an amendment to The Town and Country (General Permitted Development) (England) Order (GPDO) came into force allowing the construction of additional storeys on top of existing houses, with the usual complicated caveats. Schedule 2, Class AA of the GPDO sets out the criteria that must be adhered to but, in broad terms, if the house is two storeys high, an additional two storeys can be built on top of the original footprint (original is defined as the house as it was when it was first built). For bungalows only one additional storey can be built above.  

As is usual within permitted development rights, there are a number of caveats and exemptions, which can be summarised as follows; additional storeys are not allowed if:

  • The property is within a Site of Special Scientific Interest, Conservation Area, AONB, the Broads, a National Park or a World Heritage Site
  • The property was built before 1st July 1948
  • The property has previously been extended vertically
  • The overall height exceeds 18m when extended
  • Any additional structure is visible.

The original purpose behind domestic extensions under permitted development rights was to provide a method of futureproofing properties to facilitate family growth, essentially allowing homeowners to extend their house without having to apply for planning permission. It also released the pressure on the local planning authority so it would not have to process as many smaller applications whilst still retaining an element of control with regards scale and appearance.

This new permitted development allowance, along with the ‘larger homes extensions’ introduced in 2013, presents exciting new opportunities to not only extend your property, but to use the parameters to create interesting and exciting spaces. A vertical extension has the potential maximise long distance views that are perhaps screened or not taken advantage of due to the current internal layout of a property.

Whilst these types of extensions are not allowed in most sensitive locations, they are allowed in the green belt. This provides some interesting opportunities in areas where the size of residential extensions can be restricted. With no permitted development controls on houses within the green belt there may be possibilities to increase the size of your house by more than 150% in some cases.  

The technical guidance has yet to be fully tested however at Base we are currently reviewing two schemes that might look to utilise the new regulations as part of a wider strategy for the potential redevelopment of a property. We’ll keep you posted on how these projects progress, but if this is something you would like Base to look at for you, please get in touch!

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