Shop to mixed use with a flat above under Part 3

Part 3 of Schedule 2 to the General Permitted Development Order 2015 contains a class that allows a shop or other Class E premises, and also a betting office, pay day loan shop or hot food takeaway, to change to a mixed use combining that commercial use with up to two flats. There is a matching class allowing the reverse change back to the sole commercial use. It is the quiet route that suits a landlord who wants the rental income from upstairs without giving up the shop.

One caution before any of the detail. Part 3 has been re-lettered and rewritten repeatedly since the Use Classes Order was recast in September 2020, and further amendments have followed. Read the current consolidated text on legislation.gov.uk before you rely on a class letter you saw in an older article, including this one.

Which route fits which plan

Three different permitted development routes get confused, and they lead to different places.

A mixed use with up to two flats keeps the commercial use in existence. The planning unit becomes a single mixed use rather than two separate units, and the reverse class lets you go back. This suits a shop that trades, with underused space above.

A full change from Class E to residential under Class MA converts the whole premises to dwellings. It needs prior approval, the restrictions on it have been amended since it was introduced, and an Article 4 direction removing it is in force across many town centres. That is the route for a unit you do not intend to trade from again.

A change to dwellings under the older retail to residential class carries a cumulative floorspace limit and its own prior approval requirements. It predates Class MA and still has uses.

The mixed use route is the one most often overlooked, and on a small parade it is frequently the only one available, because Article 4 directions tend to target the full residential conversions rather than the mixed use class.

Limits on the commercial element

The class works by adding flats to a continuing commercial use, so the commercial element has to survive in substance. Three practical constraints follow.

The flats must be formed within the existing building. There is no right to extend, raise the roof or build outwards, and any external works need permission or a separate permitted development right in their own right.

The number of flats is capped at two. A shop with three floors above cannot deliver three units by this route.

And the commercial floorspace that remains has to remain usable. A scheme that leaves a 6 m² shop as a token frontage is vulnerable to the argument that the use has in truth changed entirely, which matters when the reversion class is later relied on or when a buyer's solicitor examines the planning position.

Buildings that are listed or are scheduled monuments are excluded, and several Part 3 classes are restricted on article 2(3) land, which includes conservation areas. Check both before spending anything.

Conditions attached to the residential units

Two conditions introduced by amendment apply across Part 3 residential conversions, and they are the ones that most often defeat a scheme on paper.

Natural light. Every habitable room in a dwelling created under Part 3 must have adequate natural light. A rear room in a deep plan with no window, or a room borrowing light through another room, will not satisfy it.

Space standards. Dwellings created under these classes must meet the nationally described space standard, which sets minimum gross internal areas by occupancy and bedroom count, and minimum bedroom sizes and storage. A one-bedroom one-person flat below the standard cannot be created under permitted development even where a comparable unit already exists in the building next door.

Measure the proposed layout against the standard before drawing anything else. It is the fastest way to find out whether the upper floors work.

Access, refuse and cycle storage

Independent access is the design problem. A flat reachable only through the shop fails on fire escape grounds and is impractical to let.

The usual solutions are a separate front door beside the shopfront leading to a protected stair, or an external stair to a rear entrance where the plot allows. Both change the frontage, and altering a shopfront in a conservation area or on a listed building needs consent in its own right.

Refuse is the second problem. A flat over a shop needs somewhere to store containers for residual waste, dry recycling and food waste that is not the pavement and not the shop's own store. On a terraced parade with no rear access, that space usually has to come out of the ground floor.

Cycle storage requirements come from the local plan rather than from the Order, but the council will raise them if a planning application is needed for any associated works.

Noise between the commercial use and the flat above is worth resolving at design stage rather than after the first complaint. Where the ground floor use generates plant noise, extraction or late trading, a Noise Impact Assessment sets out the exposure and the mitigation, and for a takeaway the extraction route is usually the harder question.

Reverting to the commercial use later

The reverse class allows a change from the mixed use back to the sole commercial use. Two points matter.

The right runs with the building, so a later owner can use it, but it depends on the mixed use having been lawfully established in the first place. Keep the evidence: dated photographs, council tax and business rates records, tenancy agreements and the building regulations completion certificate.

And reverting means removing the residential use, not merely ceasing to let the flat. A flat left vacant is still in residential use, so the reversion is a real operation with real cost.

Building Regulations on a change of use

Creating a flat over a shop is a material change of use for Building Regulations purposes, and the requirements are more demanding than people expect. Expect to address:

• Fire safety, including a protected escape route from the flat that does not pass through the commercial unit, and fire separation between the two uses to the required period.
• Sound insulation between the commercial use and the dwelling, with pre-completion testing where applicable, since conversions cannot rely on the same evidence routes as new build.
• Thermal elements upgraded where they are being renovated, and controlled fittings meeting the current standards.
• Ventilation to the new habitable rooms and to the kitchen and bathroom.
• Combustion appliances and flues where a boiler is being installed.
• Drainage, including whether the existing stack can take the additional loading.

Put the building control application in before the tender, not after. Fire separation between a takeaway and a flat above is the item that most often changes the specification, and finding that out during the fit-out is expensive.

Evidence of the existing lawful use

Every Part 3 right depends on the existing use being what you say it is, and the burden of proof sits with you.

The documents that settle it:

1. Business rates records showing the rateable use and the occupation dates.
2. Leases and tenancy agreements.
3. Previous planning permissions and any earlier prior approvals for the premises.
4. Dated photographs of the frontage and the interior.
5. Utility accounts in the trading name.

Where the history is muddled, or where a previous owner may have changed the use without permission, apply for a Lawful Development Certificate. A certificate of an existing lawful use under section 191 of the Town and Country Planning Act 1990 establishes the baseline, and a certificate of a proposed use under section 192 confirms that the change you intend is lawful. Both cost less than an enforcement dispute.

Article 4 directions are the last thing to check, and the easiest to miss. A direction can remove any of these rights in a defined area, and town centre directions are common. Our note on Article 4 directions and HMO changes explains how to find one, and the prior approval sequence works the same way for any class that requires it.

Where an application does become necessary, the case for the mixed use belongs in a short Planning Statement covering the town centre policy position, the retention of the commercial frontage and the residential amenity of the new units.

This is general guidance, not legal advice. Permitted development rights turn on the current wording of the Order and on whether rights have been removed locally, and a Lawful Development Certificate is the only formal way to confirm that a change of use is lawful. Check the position with your local planning authority or a qualified professional.

Enter your postcode on PlanScope to see which documents a mixed use conversion is likely to need. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.