Buckinghamshire · Two unitary councils

Architects in Buckinghamshire — chartered, fixed fee

Buckinghamshire reorganised in 2020: the four old districts became a single unitary council, so one authority now decides everything from a Beaconsfield Green Belt extension to an Aylesbury loft. Milton Keynes remains separate.

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Which council decides your Buckinghamshire application?

Buckinghamshire Council, a unitary authority created in April 2020 by merging Aylesbury Vale, Chiltern, South Bucks and Wycombe district councils with the county council. One planning authority now covers the whole area, which has simplified the administration considerably — though the legacy Local Plans of the four former districts continue to carry weight in their own areas until fully replaced.

Milton Keynes City Council is a separate unitary authority and has been since 1997. A Milton Keynes project is decided entirely independently of Buckinghamshire Council, under its own plan and validation list.

2020
Unitary reorganisation
£840
Drawings from, fixed
£258
Householder council fee

How much of Buckinghamshire is designated?

A great deal of it. The Chilterns National Landscape covers most of the south of the county, taking in Amersham, Chesham, Great Missenden, Marlow and the wooded valleys around High Wycombe. Within it and within its setting, schemes are assessed on landscape and visual impact — prominence in views from the escarpment, roof form, and the use of local materials such as flint, brick and clay tile.

The Metropolitan Green Belt covers much of the former South Bucks and Chiltern districts, including Beaconsfield, Gerrards Cross, Denham and Iver. Extensions there are tested against whether they are a disproportionate addition to the original dwelling, and replacement dwellings against whether they are materially larger than the building they replace. Where Green Belt and Chilterns overlap — as across much of Amersham and Beaconsfield — both tests apply.

The larger home extension prior approval route, which allows 6 and 8 metre single-storey rear extensions elsewhere, is unavailable on designated land. In practice that removes it from a substantial share of the county, and pushes schemes toward a full householder application at £258 with a proper design justification.

What kind of work do we do across Buckinghamshire?

  • Extensions and remodels in Beaconsfield, Gerrards Cross and Amersham, where the Green Belt volume test rather than neighbour amenity is the governing constraint.
  • Loft conversions across the interwar and post-war stock of Aylesbury, High Wycombe and Milton Keynes — usually straightforward permitted development with a £129 certificate.
  • Replacement dwellings on Green Belt plots, assessed on whether the new house is materially larger than the one it replaces.
  • Chilterns valley and escarpment schemes around Chesham, Great Missenden and Marlow, where materials and prominence in long views decide the outcome.
  • Annexes and outbuildings, where the test is whether the accommodation is genuinely ancillary to the main house rather than a separate dwelling — a much harder case in the Green Belt.
PackageFixed feeTurnaround
Essentials — measured survey, existing and proposed plans£84014–20 working days
Loft conversion package — survey, plans, sections, elevations£1,22514–20 working days
Mansard / roof rebuild package£1,57518–24 working days
Complete — planning plus building regulations drawings£1,75020–28 working days

Buckinghamshire planning questions

Which council handles planning in Buckinghamshire?

Buckinghamshire Council, a single unitary authority created in April 2020 from Aylesbury Vale, Chiltern, South Bucks and Wycombe district councils plus the county council. Milton Keynes is a separate unitary authority and has been since 1997.

Is my property in the Chilterns National Landscape?

Much of southern Buckinghamshire is, including Amersham, Chesham, Great Missenden, Marlow and the valleys around High Wycombe. Inside it and in its setting, schemes are assessed on landscape and visual impact and on the use of local materials.

Can I use the 6 metre prior approval route?

Not on designated land, which rules it out across a large share of the county. Where the property is outside the National Landscape and any conservation area, the route allows 6 metres on a terraced or semi-detached house and 8 metres on a detached house for £120.

Can I replace a house in the Buckinghamshire Green Belt?

Often yes, provided the replacement is not materially larger than the building it replaces. That test is applied on volume and footprint, so a like-for-like replacement with better internal planning is far easier to justify than an enlargement.

How much do Buckinghamshire drawings cost?

The same fixed fees as London: £840 Essentials, £1,225 for a loft package, £1,575 for a mansard or roof rebuild and £1,750 for the Complete package covering planning and building regulations from one survey.

Last updated: 28 July 2026 · Written by the Architectural Drawings London technical team, chartered members of the Chartered Institute of Architectural Technologists (MCIAT). · About our team

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