Planning · Conservation
Conservation Area Extensions and Consents in Hampstead
Conservation areas shape what you can do to a home’s exterior. This guide explains why design quality matters, what is assessed, and how to approach a sensitive proposal.
What conservation areas are
A conservation area is a place designated by the local authority for its special architectural or historic interest, where there is extra control over change to preserve or enhance its character. Much of Hampstead and many prime London neighbourhoods are covered by conservation areas, which affects what can be done to the exterior of a property and how proposals are assessed.
Why design quality matters
In a conservation area, the bar for design quality is higher. Extra floor area alone rarely wins approval; the proposal must respond to the character the designation protects. Well-judged scale, proportion, materials and detailing make the difference between a supported scheme and a refusal, so design effort early in the process is well spent.
Materials, scale, massing and neighbours
Assessments focus on how a proposal sits within its context: the materials used, the scale and massing of new work relative to the existing building and its neighbours, and the effect on the street scene and adjoining properties. Rear extensions are considered for their relationship to the established rear building line and the amenity of neighbours, including daylight, sunlight and overlooking.
Rear extensions
Rear extensions are common in conservation areas but are designed with care for the established building line, the proportion of garden retained, and the effect on neighbours. A well-proportioned, sensitively-detailed rear extension is more likely to be supported than an overly large or poorly-related addition.
Windows and external alterations
Windows, doors, rooflines and boundary treatments are closely scrutinised in conservation areas, and sympathetic or like-for-like detailing is often expected. Changes that would be trivial elsewhere — replacing windows, altering a roof, adding rooflights — can be assessed carefully here, and in some cases permitted development rights for these works are removed by an Article 4 direction.
Local authority differences
Each London borough produces its own conservation-area appraisals and design guidance and applies them through its case officers. Hampstead largely falls within Camden, but boundaries with Barnet and Westminster mean the relevant authority and appraisal should always be confirmed for a specific address.
Drawings required
A conservation-area proposal typically requires existing and proposed plans, elevations and sections, a site and location plan, and often a design or heritage statement explaining how the proposal responds to character. We prepare these and present the design with a clear conservation rationale — though, as with all planning, approval cannot be guaranteed.
Frequently asked questions
Can I still extend in a conservation area?
Will I be able to change my windows?
Explore further
Related services and areas
Need drawings or planning advice for your property?
Tell us the property address, type and what you are considering. We will advise the likely route — planning, building regulations, or both — and what information will be needed.