This guide explains planning permission rules affecting dormer extension developments in Milton Keynes.
Most householder development follows national permitted development rules unless local restrictions apply.
Single-storey rear extensions up to 4 metres in height and up to 4 metres from the original rear wall for detached houses (3 metres for other types of houses) can be normally built under
, subject to limitations on the area covered and their projection above the existing roof slope.
Information about development plans, adopted and emerging SPDs, neighbourhood planning and monitoring.
by up to 50 cubic metres for detached and semi-detached houses, and 40 cubic metres for terraced houses. Rooflights can also be installed.
The materials used in any of the above works must be similar in appearance (colour, texture, style and size) to the existing house. This means that permission is required if it is intended to render the extension, or clad it with timber, if the house is constructed in brick.
Read about Milton Keynes' heritage and find information about conservation areas and listed buildings
Read about Milton Keynes' heritage and find information about conservation areas and listed buildings
Last verified 2026-01
UK permitted development legislation allows many dormer extension projects without planning permission provided certain limits are followed.
However local planning authorities such as those covering Milton Keynes may impose additional planning controls through conservation area policies or Article 4 directions.
Many dormer extension projects in Milton Keynes may fall under permitted development rights if they remain within national planning limits.
Single-storey rear extensions up to 4 metres in height and up to 4 metres from the original rear wall for detached houses (3 metres for other types of houses) can be normally built under
Information about development plans, adopted and emerging SPDs, neighbourhood planning and monitoring.
Yes. Additional planning restrictions may apply in conservation areas or where Article 4 directions remove permitted development rights.
Planning applications for dormer extension projects in Milton Keynes are handled by the local planning authority covering Milton Keynes, Buckinghamshire.
For official planning advice consult the council planning portal for your area or visit the UK Planning Portal.
This guide summarises planning rules affecting dormer extension developments in Milton Keynes.
Planning regulations may change and additional local planning policies may apply. Always confirm planning requirements with your local planning authority before starting development.
Last updated March 2026