Class A – Commercial Extensions & alterations of properties in Use Class E

Class A of Part 7 includes commercial extensions, new windows, doors and other alterations. Class A applies to any building in Use Class E, but also to any building that is partially in use as Use Class E, as long as the alteration or commercial extension is not undertaken on those parts not falling within Use Class E. It is also important that any extensions or other alterations are solely for purposes of the business within Use Class E.

Commercial extensions under Class A of Part 7

Commercial Extensions

Class A allows for the commercial extension of any property within Use Class E. This includes shops, offices, gyms, cafes, restaurants and much more. There are however a few limitations. It also allows for other alterations, such as new windows and doors under Use Class E.

The new commercial extension must be on the ground floor only and is limited to 25% or 50 sq m on Article 2(3) land or a SSSI or 50% or 100 sq m otherwise whichever is the lesser. If the curtilage shares a boundary with any residential property in Use Class C or is on Article 2(3) land or a SSSI then the commercial extension must be at least 2m from that boundary. There is a maximum height of 4m.

Note that where a shop, for example, is being extended to the rear; you need to keep at least 2m away from any boundary that contains a residential dwelling. Therefore if the shop is in a parade, and those shops have flats above them, you would need for the extension to be 2m away from the side boundary if next door has a flat above the shop. This might cause issues with a commercial extension to the rear of the property.

You cannot add a commercial extension to the front of any use Class E property under Class A.


Class MA conversions

If you are considering perhaps a commercial extension to a shop or office under Class A, and then looking to convert under Class MA we would think that the new commercial extension would need to have existed for at least 2 years in order to comply with Class MA rolling date stamp.



Other alterations to the building

Class A of Part 7 allows for other alterations. Like Class A of Part 1, this includes new windows and doors. However again there are a few limitations.

You cannot alter a building on Article 2(3) land. This will include Conservation area, AONB, National Parks etc.  You also can’t construct any raised platforms above 0.3m, which is common to many others parts of the GPDO.

You can’t alter the shop front or replace the security grill or shutter under Class A or indeed extend to the front.

Finally any alterations must be on the ground floor only. So no new windows above the ground floor. You would need planning for that.


Extra permission required? 

As long as you comply with the legislation below, you may crack on with the works. There is no prior approval requirement. However you may like to seek the guidance of Planning Geek in the process. Please contact us for any assistance or book a Zoom call today. You might decide upon a certificate of lawfulness either before or after the works if required. The team at Planning Geek can handle that for you.





Class A – extensions etc of commercial, business or service premises

Permitted development

A. The extension or alteration of a commercial, business or service establishment.

Development not permitted

A.1 Development is not permitted by Class A if—

(a) the gross floor space of the original building would be exceeded by more than—
(i) in respect of an original building or a development on—
(aa) article 2(3) land, or
(bb) a site of special scientific interest,
25% or 50 square metres (whichever is the lesser);
(ii) in any other case, 50% or 100 square metres (whichever is the lesser);

(b) the height of the building as extended would exceed 4 metres;

(c) any part of the development (other than an alteration)—
(i) is on land which—
(aa) adjoins other premises which are used for a purpose falling within any of the classes in Part C (residential premises or institutions) of Schedule 1 to the Use Classes Order,
(bb) is article 2(3) land, or
(cc) is a site of special scientific interest, and
(ii) is within 2 metres of any boundary of the curtilage of the premises;

(d) the development would be within the curtilage of a listed building;

(e) any alteration would be on article 2(3) land;

(f) the development would consist of or include the construction or provision of a verandah, balcony or raised platform;

(g) any part of the development would extend beyond the front of any existing building;

(h) the development would involve the insertion or creation of a new shop front or the alteration or replacement of an existing shop front; or

(i) the development would involve the installation or replacement of a security grill or shutter on a shop front.


A.2 Development is permitted by Class A subject to the following conditions—

(a) any alteration is at ground floor level only;

(b) any extension is, in the case of article 2(3) land, constructed using materials which have a similar external appearance to those used for the building being extended; and

(c) any extension or alteration is only to be used as part of, or for a purpose incidental to, the use of the commercial, business or service establishment.

Interpretation of Class A

A.3 For the purposes of Class A—

“commercial, business or service premises” means a building, or part of a building, used for any purpose within Class E (commercial, business and service) of Schedule 2 to the Use Classes Order and includes buildings with other uses in other parts as long as the other uses are not within the parts being altered or extended;

“raised platform” means a platform with a height greater than 0.3 metres,

and where 2 or more original buildings are within the same curtilage and are used for the same undertaking, they are to be treated as a single original building in making any measurement.


Legislation on



Shop Extensions and other alterations Page Updated:  27th June 2024