Nationally, permitted development covers most modest householder work. In Richmond upon Thames, it covers considerably less, and on many streets it covers almost nothing.
That is not a complaint about the council. It is a description of how many separate layers of control sit over the same borough, and each one removes a different set of rights. Comparing the national baseline against what actually survives locally is the only useful way to establish where you stand.
What the National Rules Grant You
The General Permitted Development Order sets the starting position for a house, not a flat.
A single storey rear extension of 3 metres on an attached property or 4 metres on a detached one, extendable to 6 and 8 metres through prior approval. A two storey rear extension of 3 metres, provided it sits at least 7 metres from the rear boundary. A side extension at single storey up to half the width of the original house. Roof enlargement of 40 cubic metres on a terrace or 50 on a detached or semi detached property. Outbuildings within 50 percent of the curtilage.
Those permitted development rules are the national floor. Everything below describes what Richmond takes off it.
What Conservation Area Designation Removes
Richmond has more than 70 designated conservation areas, and by some counts considerably more, which makes it among the most conservation dense boroughs in London. Coverage spans Richmond Hill, Kew Green, Petersham, Strawberry Hill, St Margaret’s, the Twickenham and Teddington riversides, and the Barnes and Castelnau streets across the river.
Inside a conservation area, four things go:
- Side extensions of any size
- Two storey rear extensions
- Roof enlargement, which removes dormers, hip to gable and mansards
- The 6 and 8 metre prior approval route, since it is unavailable on designated land
Single storey rear extensions survive, but reduce to 3 metres on all house types including detached.
What the Basement Direction Removes Borough Wide
This is the borough’s defining householder control, and it applies regardless of conservation status.
On 28 February 2017 the council made a direction under Article 4(1) of the GPDO withdrawing permitted development rights for subterranean development granted by Class A of Part 1 of Schedule 2. It came into force in April 2018.
The wording is deliberately broad. It captures the formation of basements, light wells, rooms, cellars or any other usable space beneath a dwelling house, or below ordinary ground level in proximity to one.
The direction covers the whole administrative area other than those areas at greatest flood hazard, and a separate direction addresses those. The practical outcome is that every basement in Richmond requires a full planning application, with a basement assessment expected alongside it. Front light wells are limited, and proposals occupying more than half the front or rear garden may be refused.
What Street Level Article 4 Directions Remove
Beyond basements, the council operates extensive Article 4 directions across numerous streets, most of them within conservation areas.
Between them these remove permitted development for extensions, windows, doors, painting, rendering, chimneys, front garden paving and boundary treatments. A separate direction covering 62 designated areas removes Class MA rights for commercial to residential conversion.
That list is worth reading carefully, because several items on it are things homeowners never think of as development at all. Repainting a front elevation or laying a new front drive is not obviously a planning matter until a direction says it is.
What Green Belt and Metropolitan Open Land Remove
Green Belt covers around 140 hectares of the borough, and combined with Metropolitan Open Land the two account for more than half of Richmond’s area.
On that land the assessment shifts from dimensional compliance to whether an addition is disproportionate over and above the size of the original building, measured against the house as it stood in 1948. Dimensions that satisfy the national rules elsewhere carry little weight here.
What Actually Survives
Put the layers together and the residue is narrower than most homeowners expect, though not empty.
Outside designated areas and outside any relevant direction, the full national position generally holds. Inside a conservation area, you are usually left with a single storey rear extension of up to 3 metres, rooflights on slopes not fronting a highway, and outbuildings subject to tighter limits.
Everywhere in the borough, basements need permission. And flats and maisonettes never had extension rights to begin with, which matters given how much of Richmond’s period stock has been subdivided.
Why the Local Plan Change Matters Now
Richmond adopted a new Local Plan and Policies Map on 7 October 2025, replacing the Local Plan of July 2018 and the Twickenham Area Action Plan of 2013.
Under section 38(6) of the Planning and Compulsory Purchase Act 2004, applications must be determined in accordance with the development plan unless material considerations indicate otherwise. So the policy numbers your application is assessed against changed less than a year ago.
Any advice, drawing set or quote prepared against the 2018 plan was written for a superseded document. That is worth checking with whoever is handling your project, because policy citations in a design and access statement are one of the first things an officer reads. Local architects richmond homeowners appointed should be working from the October 2025 plan and the accompanying House Extensions and External Alterations SPD.
The Two Checks That Settle Your Position
Neither costs anything and both take days rather than weeks.
Confirm whether your address sits inside a conservation area, and separately whether any Article 4 direction applies to your street. Clearing one tells you nothing about the other, and Richmond publishes both the conservation area boundaries and the Article 4 register, including the basement direction and its map.
Then confirm whether the property is a house or a flat, and whether any part of the plot falls within Green Belt or Metropolitan Open Land.
Four answers, all public. They determine whether you are working within the national rules, working within a much reduced version of them, or making a full case to an officer. In a borough this heavily designated, that answer is worth having before a single line is drawn rather than after.
