Do Flats Have Permitted Development Rights? What Flat Owners in London Need to Know

Permitted Development rights are granted under the Town and Country Planning (General Permitted Development) (England) Order 2015. The rights that allow house extensions, loft conversions, and outbuildings (Part 1, Classes A–H) specifically apply to 'dwellinghouses'.

**The legal definition of 'dwellinghouse'** in planning law does not include flats or maisonettes — it refers to a single-family dwelling that occupies its own plot or curtilage, typically with its own roof and separate external entrance at ground level.

• **Why the distinction matters**:
• •A flat is a self-contained unit within a larger building
• •The building itself may be divided into multiple units, each with its own owner or leaseholder
• •Changes to the building structure (roof, external walls, common areas) affect other flat owners and the freeholder
• •Planning control recognises that individual flat owners should not be able to unilaterally alter shared structures

**What this means in practice**: For owners of flats and maisonettes in London, virtually all external alterations to the building — including any changes to the roof, external walls, windows, or the addition of outbuildings in the shared garden — require planning permission. The Permitted Development route available to house owners is not available.

• **Internal works (no planning permission required)**:
• Most internal works within a flat do not require planning permission — planning is concerned with external appearance and land use. A flat owner can typically carry out (without planning permission):
• •Internal remodelling (removing or adding non-structural internal partitions)
• •Kitchen renovation
• •Bathroom renovation
• •Flooring, decoration, and finishes
• •Electrical rewiring (requires Building Regulations notification via Part P)
• •Boiler replacement (requires Gas Safe registration and Building Control notification)

**Note on listed buildings**: even internal works require Listed Building Consent if the flat is in a listed building.

• **External works on a flat — what requires planning permission**:
• •Installing a satellite dish (antennas on a flat require planning permission, unlike some house applications)
• •Replacing windows with different design, framing, or glazing
• •Installing air conditioning or heat pump outdoor units on an external wall or roof
• •Solar panels on a shared roof
• •Any extension or addition to the flat's external envelope

• **Communal garden or roof terrace — what requires planning permission**:
• •Building an outbuilding in the communal garden (garden is shared — the flat owner may not even have legal rights to build there)
• •Creating a roof terrace from a flat roof
• •Installing a garden room or studio in a communal garden

**Loft conversion in a top-floor flat**: For owners of top-floor flats where the loft above is included in the demise (lease), a loft conversion requires planning permission — even a Velux-only conversion. The flat's Permitted Development rights for residential loft conversions do not apply.

**Roof terrace on a top-floor flat**: Creating a roof terrace — even where the flat owner has a terrace or flat roof within their demise — requires planning permission in almost all cases. This is because a roof terrace changes the use of the roof structure and typically affects the character and appearance of the building.

For most flat owners, the property is held on a leasehold basis — the flat owner holds a long lease from the freeholder (typically 99–999 years). The freeholder owns the building structure (including the roof, external walls, and foundations).

**Lease consent as well as planning consent**: Even where planning permission is obtained for an alteration, the flat owner must also obtain consent from the freeholder under the terms of the lease. Most leases prohibit alterations to the structure or exterior of the building without the freeholder's written consent.

• This means a flat owner seeking to:
• •Create a loft conversion
• •Add a roof terrace
• •Alter external windows
• •Extend into communal space

...must first obtain leasehold consent from the freeholder AND then apply for planning permission. Both are required.

**Section 61 — Alterations and improvements**: Most standard flat leases include a clause (often Section 6 or similar) that requires the leaseholder to obtain consent for any structural alterations. A freeholder can refuse consent for alterations that affect the structure — and often will do so to protect the building's integrity and the interests of other leaseholders.

**Collective enfranchisement**: Where flat owners have collectively purchased the freehold (through collective enfranchisement), the need for freeholder consent is managed collectively — the flat owner may need to obtain consent from the residents' management company or other leaseholders rather than an external freeholder.