Can I convert the hip to a gable on one side of a semi in Reigate and Banstead?

Under permitted development the national limits decide, not the council's guidance. If planning permission is needed, for example in a conservation area, the council's 2004 SPG says changing between hips and gables on one half of a pair of semis is unacceptable, though a designer may argue a mix in a Design Statement. We would treat it as a case needing that argument and consider pre-application advice.

Which dormer style does Reigate and Banstead prefer?

The SPG names three: a gabled dormer on a gabled roof, a hipped dormer on a hipped roof (both with a pitch of 45 degrees or more), and a flat-roofed dormer with an ogee cornice, which it says suits many roof forms, particularly pre-war. It asks for the window to relate to those below, the dormer to sit below the ridge and away from the hip, and narrow cheeks. A full-width box dormer is the opposite of that brief.

Will a dormer be refused if no one else in my street has one?

It can be a problem where planning permission is needed. The SPG says dormers will look out of place, even where well designed, if there are none in the street, and that a refusal is possible even if a few similar examples exist nearby. Its answer is to place the dormer where it is not visible from the street or other public viewpoints, which usually means the rear slope.

How is the 40 m³ or 50 m³ measured?

It is the volume added beyond the original roof slope, including any earlier roof extensions, not the floor area of the new room. We calculate it on the drawings and include the calculation in the Lawful Development Certificate application.

Can I have a front dormer?

Not under permitted development: nothing may extend beyond the plane of the roof slope facing a highway. Front rooflights are fine. A front dormer needs planning permission and most councils refuse them unless the street already has them.

Do I need Building Regulations approval as well?

Yes, always. Permitted development and planning permission concern what you may build; Building Regulations govern how it is built, including the new floor structure, the stair, fire escape and insulation. We prepare that package after the planning route is confirmed.

How long does Reigate and Banstead take to decide?

The statutory period is 8 weeks from validation for both a householder application and a Lawful Development Certificate, and 42 days for a larger home extension prior approval. Decisions can run past the statutory 8 weeks; allow 8–12 weeks.

Loft Conversions in Reigate and Banstead

Lofts in Reigate and Banstead follow the housing. The 1930s semis of Nork, Banstead, Earlswood and Merstham are the usual candidates for a rear dormer, often with a hip-to-gable end. The Victorian and Edwardian terraces and villas of Reigate and Redhill are more likely to sit in a conservation area. On Reigate Hill and in Kingswood and Chipstead the large detached houses are mostly in the Green Belt, so a loft that adds bulk is judged against the house as originally built. Where a planning application is needed, the council's own 2004 dormer guidance is still the yardstick officers use.

The permitted development rules for loft conversions

A loft conversion with a rear dormer is permitted development on a house if the added roof volume is no more than 40 m³ on a terraced house or 50 m³ on a semi-detached or detached house, the dormer sits at least 200 mm back from the eaves and no higher than the ridge, there is no dormer on the roof slope facing the road, materials are similar in appearance, and side windows are obscure-glazed.

Flats and maisonettes have no permitted development rights, so a loft to a top-floor flat always needs planning permission. Full-width box dormers that reach the ridge, and hip-to-gable conversions on semis whose volume exceeds 50 m³, also fall outside the allowance.

What changes in Reigate and Banstead

Roof extensions are not permitted development in a conservation area, so a dormer or hip-to-gable there needs a householder planning application designed to the area's appraisal.

The local constraints that most often decide the route in Reigate and Banstead are listed below, taken from our Reigate and Banstead area page. Each one is a reason to confirm the address on Reigate and Banstead's constraints map before relying on permitted development.

Green Belt. Most of the borough outside Reigate, Redhill, Banstead and Horley is Green Belt, including land around Kingswood, Chipstead, Merstham, Salfords and the North Downs. Source
Surrey Hills National Landscape. The North Downs above Reigate, including Reigate Hill, Colley Hill and the scarp towards Merstham, fall within the Surrey Hills National Landscape (formerly the Surrey Hills Area of Outstanding Natural Beauty). Source
Conservation areas. Reigate town centre, Banstead, Chipstead, Kingswood and Merstham are among the borough's conservation areas. Source
River Mole and Redhill Brook flood risk. The River Mole and its tributaries run through Horley, Salfords and Sidlow, and the Redhill Brook drains Redhill and Earlswood towards the Mole. Source
Listed buildings. Reigate town centre, Banstead, Chipstead, Merstham and the villages contain many listed houses, cottages and churches. Source

What the council's dormer guidance expects of a loft

The council's Householder Extensions and Alterations SPG (March 2004) says a dormer should use a similar roof design to the house and relate in size, proportion and materials to the existing windows. It names three appropriate types: gabled on gabled buildings and hipped on hipped buildings, both with a pitch of 45 degrees or more, and flat-roofed with an ogee cornice, which it describes as suitable for many roof forms, particularly pre-war. The window top should generally be no higher than the middle of the roof, the dormer set back from the wall, below the ridge and away from the hip, with narrow cheeks.

The SPG warns that dormers are often refused for poor design or a prominent position, and that a dormer will look out of place, even if well designed, where the street has none. It acknowledges that Building Regulations headroom can push a dormer towards the ridge, so it asks for a position not visible from the street or other public viewpoints, and accepts that some low-pitched or short-span roofs cannot take a dormer at all. The 2021 Local Character and Distinctiveness Design Guide adds that dormers should not dominate the roof plane or be used to gain headroom over a great width, and that rooflights should generally be restricted to rear elevations.

On hip-to-gable work, the SPG calls changing between hips and gables on one half of a pair of semis unacceptable, while leaving it open to a designer to argue a mix in a Design Statement. That is the standard a planning application on a 1930s semi is read against, for example in a conservation area.

How the Green Belt policy treats a roof alteration

Policy NHE5 of the Development Management Plan permits extensions or alterations to a Green Belt building where the design respects its original form and the character of the area, and the additions, in combination, are not disproportionate to the original building, meaning the house as originally built or as it stood on 1 July 1948, whichever is later.

The policy lists what is weighed: the additional footprint and floor area, the massing and bulk, the height, and the location and visual prominence of the alteration. A rear dormer adds to the second, third and fourth of those, so on a Green Belt house that has already been extended we establish the original building first. The policy sets no percentage.

What Reigate and Banstead planning officers look for

On Reigate Hill and in Kingswood and Chipstead plot coverage, tree protection and the spacious, wooded character of the road carry more weight, and inside the Surrey Hills the landscape impact is tested too. In the Green Belt officers usually measure the extension against the original dwelling by floorspace or volume and treat outbuildings more strictly. Common refusal reasons are full-width box dormers, side extensions that create a terracing effect, and disproportionate additions in the Green Belt. The council offers a paid pre-application service.

Fees and timelines

Reigate and Banstead decides a householder application or a Lawful Development Certificate within 8 weeks of validation. The council fee is £528 for a householder application and £264 for a Lawful Development Certificate (England, from 1 April 2025; verify before applying).

Our own fee is fixed once quoted. The quote tool gives an indicative figure in minutes and a written quote follows within 24 hours.

Primary sources

Reigate and Banstead Borough Council: Householder Extensions and Alterations SPG (March 2004)
Reigate and Banstead Borough Council: Roof Alterations - Dormers (SPG leaflet)
Reigate and Banstead Borough Council: Development Management Plan, Policy NHE5
Reigate and Banstead Borough Council: Local Character and Distinctiveness Design Guide SPD (June 2021)
The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2: the permitted development limits quoted above.
Planning Portal: do you need permission: the national guidance and the application service every council accepts.
Reigate and Banstead Borough Council: planning: the council's own constraints map, validation checklist and pre-application service.