Great Missenden House Extension Plans: Which Projects Need an Application?

Which Great Missenden extensions can go ahead without planning permission?

Only a modest single-storey rear extension can go ahead without planning permission in Great Missenden, because the Chilterns National Landscape (in law still the Chilterns Area of Outstanding Natural Beauty) is "article 2(3) land". Paragraph A.2 of Class A removes the side, two-storey and cladding rights there.

The larger home prior approval route in A.1(g) is limited to houses off article 2(3) land (GPDO 2015, Schedule 2 Part 1).

Article 2(3) land is the protected land listed in the GPDO: conservation areas, National Landscapes, National Parks, the Broads and World Heritage Sites. The Green Belt is not on that list.

Project on a house with its rights intact	Application needed here?	Rule	Drawings and our fee
Single-storey rear, up to 3 m deep (4 m detached), no more than 4 m high	No	A.1(f)	Building regulations and structural package, from £1,195
Single-storey rear, deeper than that	Yes, a householder application; prior approval is closed	A.1(g)	Planning drawings, £895
Side extension, even one storey	Yes	A.2(b)	Planning drawings, £895
Rear extension of two storeys	Yes	A.2(c)	Planning drawings, £895
Render, timber, stone or tile cladding	Yes	A.2(a)	Planning drawings, £895

Wherever the eaves come within 2 metres of a boundary, the party wall included, they must stay at 3 metres or lower to count as permitted development (A.1(i)). Row one needs nothing from the council. If a buyer will want proof, a certificate of lawfulness costs from £795 with us, and Buckinghamshire charges £274 to issue it. After a planning permission, the building work still needs building regulations drawings, £795, and structural calculations, from £425; booked together with the planning drawings, the three are our planning and building regs package, from £1,495, instead.

Our permitted development checker runs your plan against those five rows.

What does the Chiltern SPD ask of house extension plans in Great Missenden?

Where Great Missenden houses stand in a visual row with modest gaps, the Chiltern Residential Extensions and Householder Development SPD of September 2013 asks a two-storey side extension to sit at least 1 metre off the boundary at first floor (Chiltern SPD). The same guide shapes extensions in Amersham and Chesham. Above it sit the Chiltern Local Plan, adopted in 1997, and the Chiltern Core Strategy, adopted in 2011, which Buckinghamshire Council still applies in its east planning area, the old Chiltern District (council: our current plans and documents).

The parish wrote a third document itself. The Great Missenden Parish Village Design Statement of March 2012 asks designers to read it with the Chilterns Conservation Board's Chilterns Buildings Design Guide, and its guidelines name specific heights, materials and drawings.

Which estate or street is your Great Missenden house on?

The estate or street a Great Missenden house is on dates it, and the age of the house shapes the extension it can take. The design statement traces Great Missenden spreading north of the High Street after the railway arrived in 1892, then the bypass, the Misbourne and Winslow Field estates of the 1950s, and later Wychwood Rise and Rook Wood Way to the south. Prestwood grew from a few houses round the common: the Honor Road area in the 1960s, the Lovell estate around Lodge Lane in the 1970s, and much infill.

• The 1950s to 1970s estates, in both villages. Rear, side and two-storey extensions to semis and detached houses. The National Landscape rules in the table decide whether an application is needed; the Chiltern SPD decides the shape.
• High Street and Church Street. Listed buildings and the conservation area come first, and the street view plan carries the most weight.
• Ballinger, South Heath and the lanes. A house outside the villages may be in the Green Belt. There, the NPPF asks whether an extension is disproportionate to the original building, a test for planning applications only; permitted development within the table above is not judged against it. We look the address up on the policies map before any design.

What does the 2012 Village Design Statement ask of an extension?

The 2012 Village Design Statement asks an extension to respect the skyline in its ridge height and to use hand-crafted flintwork and red brick, under building guidelines for the whole parish:

• Ridge heights. New buildings should not dominate their neighbours, and ridge heights must respect the skyline. The village roofscape is seen from Frith Hill, the parish church and the paths above the valley, so a raised roof shows.
• Flint. Brick and flint is the Chilterns walling, and the statement asks for hand-crafted flintwork rather than prefabricated flint blocks.
• Brick. Red mixtures, hand-cut or rustic.
• Style. Good modern design is welcome if it enhances its surroundings; slavish copying of old features is discouraged.

On a 1950s house on the Misbourne estate or Winslow Field, we draw the roof pitch and brick to match the house rather than add a flint panel for effect. On a flint and brick cottage, the drawings specify the flintwork closely enough for a builder to price it correctly.

What extra drawings does the High Street conservation area need?

An extension in the Great Missenden High Street conservation area needs a street view plan, plus levels where the ground slopes. Buckinghamshire County Council designated the Great Missenden conservation area in 1969 and Chiltern District Council amended it in 1992 (conservation area map); it takes in the historic High Street and Church Street. The design statement counts 50 listed buildings in the village, most of them in the conservation area, and another 50 across the parish.

Three of the statement's village guidelines bear directly on drawings:

• 6.2: nothing in the conservation area should exceed the ridge height of the existing buildings on the land, or of the buildings next to it.
• 6.3: existing building lines should be kept.
• 6.7: conservation area applications should come with a "Street View Plan" showing the proposal beside the neighbouring properties.

West of the High Street the ground climbs towards the railway, and the statement warns that almost anything built there reaches the ridge height of the High Street buildings. For an address on that slope, the survey takes levels and the street view is drawn in section as well as in elevation.

Work touching a listed building or other heritage asset also needs a heritage statement on Buckinghamshire's checklist, which our Buckinghamshire Council page summarises (supporting information), which we write for its own fee, from £565. A listed house also needs listed building consent, its own application with a design and access statement, outside our planning drawings fee.

Is a 5 metre Prestwood kitchen extension a planning application?

A 5 metre kitchen extension on a Prestwood semi needs a householder application, because 5 metres is past the 3 metre limit for a semi and prior approval is closed in the National Landscape. Picture, for instance, a 1970s semi on the Lovell estate off Lodge Lane (invented for this page), with a 5 metre single-storey kitchen planned across the back.

1. Our planning drawings, survey to decision: £895.
2. Buckinghamshire Council's householder fee: £548.
3. Once permitted, building regulations drawings at £795 and structural calculations, from £425; or lines 1 and 3 booked together as our package, from £1,495.
4. The building control charge, paid to the council or a registered building control approver.

Cut the same kitchen back to 3 metres and lines 1 and 2 drop away: the drawings become our building regulations and structural package, from £1,195.

Our house extensions page sets out the service itself. Further up the A413, read about dormers and lofts in Wendover.

Frequently asked questions

Can I build a single-storey side extension in Great Missenden without planning permission? No. The parish is in the Chilterns National Landscape, where any extension beyond a side wall of the original house needs a planning application.

Can I render my extension? Not as permitted development here, since paragraph A.2(a) excludes render on article 2(3) land. With planning permission it may be accepted where render suits the street.

What is a street view plan? A drawing of your extension in the street beside the adjoining houses. The Village Design Statement asks for one with conservation area applications, and ours includes it.

Can a South Heath house build a 3 metre kitchen without applying? Yes, if it is a single-storey rear extension within the permitted development limits and the house keeps its rights; the Green Belt does not change that. The Green Belt test applies only when an application is needed, and the National Landscape rules still decide whether it is.