Part 20: Construction of New Flats in airspace

On June 25th 2020 the government announced an update to the  The Town and Country Planning (General Permitted Development) (England) Order 2015 (as amended) (GPDO) in a new 20th Part. This relates to the construction of new dwellings within England within airspace.

This part allows for the construction of new flats in airspace on a variety of buildings throughout England. None of these are permitted on Article 2(3) Land which includes Conservation areas. They all prevent the creation of HMOs in the future, without full planning, and are not available to properties that are or contain an HMO.

Check out our easy reference table to see which of these apply to which buildings

Class ZA allows for the demolition of a single detached building in existence on 12 March 2020 that was used for office, research and development or industrial processes, or a free-standing purpose-built block of flats, and its replacement by an individual detached block of flats or a single detached house within the footprint of the old building, with up to two additional storeys in the airspace.

Class A permits allows the construction of up to two additional storeys of new flats in the airspace above a purpose-built detached block of flats.

Class AA permits construction of up to two new storeys of flats in the airspace above detached buildings in commercial or mixed use, including where there is an element of residential use.

Class AB permits the construction of new flats in the airspace above terrace buildings (including semi-detached buildings) in commercial or mixed (including residential) use; two storeys may be added if the existing building is two or more storeys tall, or one additional storey where the building consists of one storey.

Class AC permits the construction of new flats in the airspace above terrace dwellinghouses (including semi-detached houses); two storeys may be added if the existing building is two or more storeys tall, or one additional storey where the building consists of one storey.

Class AD permits the construction of new flats in the airspace above detached dwellinghouses; two storeys may be added if the existing building is two or more storeys tall, or one additional storey where the building consists of one storey.

The new permitted development rights are subject to a number of limitations and conditions, including a requirement for prior approval from the local planning authority in relation to certain matters.

This is not the same as Part 3 which relates to the conversion of one building use class to another.

The various sections with Part 20 are as follows:

Table of airspace opportunities per property type

Class ZA – Demolition of buildings and construction of new flats or a house in their place

Class A – New flats on detached block of flats

Class AA – New flats on detached buildings in commercial or mixed use

Class AB – New flats on terrace buildings in commercial or mixed use

Class AC – New flats on terrace buildings in use as houses

Class AD – New flats on detached buildings in use as houses

Paragraph B – procedure for submitting a prior approval under Part 20

Paragraph C – definition of words and phrases within Part 20

This page was last updated on 19th November 2022