Extending a shop under permitted development: Part 7 limits
The shops class in Part 7 of the GPDO 2015 allows a small rear extension without permission, but the boundary rule defeats most town centre units. Here is how the limits are measured and where the right falls away.
Shop extension permitted development sits in Part 7 of Schedule 2 to the Town and Country Planning (General Permitted Development) (England) Order 2015, and the allowance is smaller than most shopkeepers expect. The shops class lets you add up to 50 m² or 25 per cent of the gross floor space of the original building, whichever is the lesser, up to a height of 4 metres, and nothing may sit within 2 metres of the boundary of the curtilage. Go past any one of those and the whole extension needs planning permission.
Part 7 also carries separate classes for industrial and warehouse premises, for schools and hospitals, and for smaller works such as hard surfaces and trolley stores. The class letters have been re-lettered and amended several times, so read the class that is in force today rather than a summary from a few years ago.
Which premises the class covers
The right is written by reference to a shop, and to a financial or professional services establishment of the kind that serves visiting members of the public: a bank, a building society, an estate agent, a professional office people walk into.
That wording has become awkward since September 2020, when the Use Classes Order was amended and most retail, financial, professional services, restaurant and office uses were folded into the single Class E. The permitted development rights were preserved by reference to the earlier descriptions rather than rewritten, so the question for your premises is not simply whether you are in Class E. It is whether the building is in use as a shop, or as a financial or professional services establishment, in the sense the Order uses.
Two common premises fall outside. A restaurant or café has never been a shop for this purpose, and neither has a hot food takeaway, which is a sui generis use. A unit that has drifted from retail into a mixed use may find the right unavailable because the building is no longer in the qualifying use at the time the works are carried out.
Where there is any doubt, an application for a lawful development certificate for a proposed use or development under section 192 of the Town and Country Planning Act 1990 settles it in advance. That certificate is the only formal way to confirm that works are lawful, and it costs a fraction of an enforcement dispute.
Floorspace and height limits
The floorspace test measures the gross floor space of the original building, not the building as it stands today. Original means the building as it was built, or as it existed on 1 July 1948 if it predates the planning system.
The allowance is cumulative. A parade unit that gained a 30 m² store room under the same right in 2009 has only 20 m² left, even if the 2009 extension was built by a previous occupier and nobody now remembers it.
| Limit | Figure | Measured against |
|---|---|---|
| Floorspace increase | 50 m² or 25 per cent, whichever is lesser | Gross floor space of the original building |
| Height of the extension | 4 metres | Ground level adjacent to the works |
| Distance from boundary | No part within 2 metres | Boundary of the curtilage of the premises |
Height is measured from the ground level adjacent to the works, which on a sloping yard is the higher point rather than the average. A flat roof extension at 4 metres leaves no room for a parapet upstand or a plant enclosure, so the roof build-up needs checking before the drawings are finalised.
The two metre boundary rule and why it bites
This is the limit that kills most schemes. Town centre retail units typically occupy the full width of their plot, with a rear yard bounded by a wall on both sides, so an extension across the back of the shop is within 2 metres of the boundary by definition.
The boundary in question is the boundary of the curtilage of the premises, not the boundary of the land in the same ownership. Where a retailer owns the yard behind two adjoining units, the internal division may not be a curtilage boundary at all, and a survey of what is actually in the planning unit is worth doing before the measurement is taken.
There is no relaxation for an agreement with the neighbour. Permitted development limits are not negotiable, and a letter of no objection has no effect on whether the right applies.
Loading bays, trolley stores and hard surfaces
Part 7 contains narrower rights that often matter more day to day than the extension class.
One allows the modification or replacement of an existing loading bay at a shop, which is useful where a servicing arrangement is being upgraded but not relocated. Another permits a hard surface within the curtilage for a purpose incidental to the use, which covers the resurfacing of a service yard or a small area of additional standing. Others deal with waste and recycling containers and with trolley stores at retail premises.
Each has its own conditions, and most of them attach requirements about surface water. Where a hard surface exceeds the thresholds in the class, or where the surface is not permeable and the run-off is not directed to a permeable area, the right falls away and permission is needed. That is the same principle that applies to domestic front gardens.
Where the right disappears completely
Article 2(3) land takes the right away. That means conservation areas, National Landscapes, National Parks, the Broads and World Heritage Sites, which between them cover a large share of the attractive shopping streets in England. If your unit is in a conservation area, assume a planning application. A short Article 2(3) land guide explains how to check.
Listed buildings and scheduled monuments are excluded as well, and a listed building brings listed building consent into play for works affecting its character, quite separately from planning permission. Article 4 directions can remove the right on a specific street or centre, and they are recorded on the council's own mapping rather than anywhere national.
Where the extension falls outside the class for any of these reasons, the application is a full one, and the supporting text should address retail frontage, servicing and the effect on the street scene. A short Planning Statement doing that job properly is usually enough for a modest rear extension.
Shopfronts, signs and the consents people forget
Altering a shopfront is not covered by the extension class. Replacing a timber shopfront with an aluminium one materially affects the external appearance of the building, so it is development and needs permission unless a specific right applies. In conservation areas councils are strict about stallrisers, pilasters, fascia depths and the loss of original joinery.
Advertisements are a separate consent regime under the Town and Country Planning (Control of Advertisements) (England) Regulations 2007. Many fascia signs benefit from deemed consent, with limits on size, projection and illumination, and those limits are tighter in conservation areas and areas of special control. Illuminated signage frequently needs express consent even where the sign itself would otherwise be deemed consented.
Getting the sign wrong is quick to correct and easy to enforce against, which is why councils pursue it.
Evidencing the original building
Since the allowance runs from the original building, the file needs to show what that was.
Useful evidence includes historic Ordnance Survey extracts, the council's own planning history for the address, building control records, old sales particulars with floor areas, and the rating list description. Where the unit has changed hands several times, the planning history is usually the strongest record, because every previous extension that needed permission will appear on it.
Set the measured survey out as gross internal and gross external area separately, and state which figure the 25 per cent is applied to. Councils responding to an enforcement enquiry will do the same calculation, and a file that already answers it ends the conversation quickly. The same evidence problem arises for industrial premises, covered in extending an industrial building or warehouse.
If your unit falls outside the class and you need the supporting documents for a full application, enter your postcode on PlanScope to see which reports the site is likely to need.
This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.
Frequently asked questions
How big an extension can a shop build without planning permission?
The shops class in Part 7 of the GPDO 2015 allows the gross floor space of the original building to be increased by up to 50 square metres or 25 per cent, whichever is the lesser. The extension must not exceed 4 metres in height and no part may sit within 2 metres of the boundary of the curtilage.
Does the allowance reset when the shop changes hands?
No. The test runs against the original building, meaning the building as first built or as it stood on 1 July 1948, and every extension built under the right since then counts against the allowance. A previous occupier's store room reduces what is left for you, whether or not anyone recalls it.
Can a restaurant or takeaway use the shops class?
No. The right is expressed by reference to shops and to financial or professional services establishments. A restaurant or cafe has never qualified, and a hot food takeaway is a sui generis use outside the class entirely. Those premises need a full planning application for any extension.
Does the right apply in a conservation area?
No. Article 2(3) land, which covers conservation areas, National Landscapes, National Parks, the Broads and World Heritage Sites, is excluded. Listed buildings and scheduled monuments are excluded as well, and an Article 4 direction can remove the right on a particular street. Check the council's own mapping before assuming otherwise.
Do I need separate consent for a new shopfront and signage?
Usually yes on both counts. Replacing a shopfront materially affects the external appearance of the building, so it is development needing permission. Signs fall under the Control of Advertisements Regulations 2007, where many fascia signs have deemed consent within size and illumination limits, and illuminated signage often needs express consent.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.