Skip to content

What are permitted development volume limits?

To qualify as permitted development some household building work projects – notably extending a house – must not exceed limits to the volume being added. The rules are currently different in England and in Wales.

In England, the volume allowance mostly applies to loft conversions. You can read more on the Planning Portal1

In Wales, volume allowance currently has a more significant role in permitted development, particularly with:

You can also use our volume calculator to find out the volume of several common development types6.


  1. https://www.planningportal.co.uk/permission/common-projects/loft-conversion/planning-permission
  2. https://www.planningportal.co.uk/permission/common-projects/conservatories/planning-permission
  3. https://www.planningportal.co.uk/permission/common-projects/extensions/planning-permission
  4. https://www.planningportal.co.uk/permission/common-projects/loft-conversion/planning-permission
  5. https://www.planningportal.co.uk/permission/common-projects/outbuildings/planning-permission
  6. https://www.planningportal.co.uk/services/professional-portal/volume-calculator

The Planning Portal is delivered by PortalPlanQuest Limited which is a joint venture between TerraQuest Solutions Limited and the Ministry of Housing, Communities & Local Government (MHCLG). All content © 2024 Planning Portal.

The Planning Portal is delivered by PortalPlanQuest Limited which is a joint venture between TerraQuest Solutions Limited and the Ministry of Housing, Communities & Local Government (MHCLG). All content © 2024 Planning Portal.