This guide explains planning permission rules affecting two storey extension developments in Hillingdon.
Most householder development follows national permitted development rules unless local restrictions apply.
Development must comply with national permitted development height limits.
Extensions must comply with national permitted development depth limits.
Development near boundaries must follow national permitted development rules.
Roof alterations must comply with national permitted development rules.
Materials should be similar in appearance to the existing house.
Additional planning restrictions may apply in conservation areas.
Listed building consent is required for works affecting listed buildings.
Last verified 2026-01
UK permitted development legislation allows many two storey extension projects without planning permission provided certain limits are followed.
However local planning authorities such as those covering Hillingdon may impose additional planning controls through conservation area policies or Article 4 directions.
Many two storey extension projects in Hillingdon may fall under permitted development rights if they remain within national planning limits.
Development must comply with national permitted development height limits.
Development near boundaries must follow national permitted development rules.
Yes. Additional planning restrictions may apply in conservation areas or where Article 4 directions remove permitted development rights.
Planning applications for two storey extension projects in Hillingdon are handled by the local planning authority covering Hillingdon, Greater London.
For official planning advice consult the council planning portal for your area or visit the UK Planning Portal.
This guide summarises planning rules affecting two storey extension developments in Hillingdon.
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