Hampstead is one of the most tightly regulated stretches of residential London. The reason is not the conservation-area designation alone. It is the Article 4 Direction that sits on top of it. The Article 4 turns a routine refurbishment into a planning application. Most owners we speak to discover the Article 4 only after commissioning drawings, which is the wrong order.
This is a practical guide for Hampstead, Belsize and South Hampstead homeowners considering a renovation, extension or roof alteration in 2026. It covers what the existing Article 4 removes, the substantial change Camden is bringing into force this June, and the two new Directions the council is introducing in Redington/Frognal and Fitzjohns/Netherhall.
All factual references in this post come from Camden Council's published Article 4 documentation and the 9 June 2025 consultation outcome. Practice notes from HXL reflect our delivery experience, not the council's position. Read your own conservation area's schedule before making any commitment.
An Article 4 Direction is a planning tool that removes some of the permitted development rights a homeowner would otherwise have. Permitted development is the legal route by which certain works (a side return, a rear dormer, a replacement window) can proceed without a planning application. Where an Article 4 applies, those works become subject to a full planning application, judged on conservation-area grounds.
Camden has Article 4 Directions over six conservation areas relevant to the Hampstead market. Hampstead Conservation Area, excluding Frognal Way. Hampstead Conservation Area Frognal Way, treated as a separate Direction. Belsize Conservation Area. South Hampstead Conservation Area, formerly called Swiss Cottage. Primrose Hill Conservation Area. And South Hill Park Estate, which sits narrowly over specific properties. The Hampstead, Belsize and South Hampstead Directions were each adopted on 1 September 2010. Primrose Hill's is older, from March 1983. Camden publishes the schedules, fact sheets and maps for each Direction on its website. Read them before commissioning any drawings. They are your binding reference.
The 2010 Directions remove permitted development rights for works that affect the conservation-area's visual character. The schedules differ slightly between areas, but in practice we see them applied to replacement of windows and doors visible from the public realm, alterations to roof structures including roof additions, mansards, dormers and visible chimney removal, changes to front-of-property boundary treatment, external painting and rendering, and hard standing within the front curtilage. A planning application is required for these works; the application is then assessed against the conservation-area appraisal and design guide. Read the schedule for your specific area before you commission drawings. The differences matter.
“An Article 4 does not block your scheme. It changes the route and adds a Conservation Officer to the table. Pre-application advice from the council, before you submit, is some of the most useful spend in the project.”
Knowing what an Article 4 does NOT remove matters as much as knowing what it does. Interior works sit outside its scope. Rear extensions that sit outside the front elevation and away from the public realm often remain permitted under standard rights, subject to size, neighbour amenity and the Conservation Officer's view of the rear. Listed building consent, a separate regime, takes precedence on listed homes. Most back-garden work that does not affect the conservation-area character falls outside Article 4 entirely. The Direction is a tool for protecting what you can see from the street, not for blocking sensible rebuild behind it.
The substantial 2026 change. On 9 June 2025 Camden issued a new Article 4 Direction for Hampstead, South Hampstead and Belsize. The single change is that photovoltaic solar panels and solar thermal equipment will no longer require planning permission, provided they meet the standard permitted development criteria. This new Direction comes into force in June 2026 and replaces the 2010 versions. Every other restriction in the 2010 Direction remains in force. The motivation Camden cites is the borough's 2019 climate emergency declaration and the 2021 Home Improvements Planning Guidance, both of which recommend low-carbon retrofit.
Camden's conditions for solar without planning are practical. Panels must not protrude more than 20cm beyond the plane of the wall or roof, must not extend above the highest part of the roof, must not be installed on a wall fronting a highway, and must not be on a listed building. Stand-alone solar in the curtilage is limited to one unit per property, 2 metres in height between the highway and the dwelling and 4 metres elsewhere, sited at least 5 metres from the boundary. The full list of conditions is in the consultation document Camden published in June 2025.
Two new Article 4 Directions are coming in alongside this. Camden is introducing Article 4 Directions over the Redington/Frognal and Fitzjohns/Netherhall Conservation Areas, which previously had no Direction. Owners in those two areas have, until now, had wider permitted development rights than their immediate Hampstead neighbours. If the new Directions are adopted (consultation closed July 2025, decision pending), that gap closes. Owners in Redington/Frognal and Fitzjohns/Netherhall planning works in 2026 should expect the same broad restrictions described above.
Practical advice for buying or already owning in any of these areas. Establish whether the property is in the Article 4 area before contract exchange, not after. Camden's online Conservation Area Map, linked from its Article 4 page, is the authoritative tool. Commission a heritage-experienced architect for the scheme design. Submit a pre-application to Camden before the full planning application is lodged. And budget additional weeks into the programme for determination, with longer assumed if heritage statements or specialist reports are likely to be requested.
HXL's role on these schemes begins after planning is in hand. As principal contractor we deliver under JCT Standard or JCT Design and Build, coordinate the Conservation Officer's inspections at the milestone points, and manage the specialist trades (period joinery, sash window restoration, lime plaster, listed-building electrical work) that conservation-area context requires. We work alongside your appointed architect rather than replacing them. Design lead belongs to the architect; build and the council coordination belong to us.
If you are still at the question-stage rather than the appointment-stage, our free Construction Clinic for Hillingdon residents covers the same ground in person. For Camden residents, your architect or a Camden-experienced planning consultant is the right first call. Either way, read the Article 4 schedule for your specific area before you commission drawings. Reading it costs nothing. Designing without it costs a full redesign.
