Help us improve our planning guidance for extensions and alterations

We are updating our planning guidance on extensions and alterations to help support the many different improvements people want to make to their properties.

Our aim is to make the guidance easier to use and to reflect changes to national planning policy.

We are asking for your comments on proposed changes to the guidance.

Take part in the consultation

Proposed changes

Proposed changes include:

  • A more positive and flexible approach to new extensions
  • Greater clarity on how to protect amenity
  • More clarity on how to avoid adverse effects on the host building and street scene
  • Clearer guidance and advice for applications within conservation areas
  • More information about sustainable building and improving biodiversity

The closing date for the consultation is Friday 16 August.

Councillor Gill Williams, lead member for planning policy, said: “Well designed alterations and extensions can transform properties and improve the quality of life for people living in them. 

“By providing clearer guidance and advice, we hope to streamline the planning process for homeowners and encourage more attractive, sympathetic and sustainable projects across the city.”


Our supplementary planning guidance (SPD) on extensions and alterations aims to support the many different improvements people want to make to their properties.

It sets out the things to consider to achieve high-quality extensions and alterations.

This is important in a densely populated place like Brighton & Hove – property owners have to take into account how their plans affect their own properties, the impact on neighbours and how they fit into the street scene.

Councillors discussed the updated draft guidance at the Tourism, Development & Culture Committee on 20 June.

How the guidance will be used

We’ll use the comments from the consultation to shape the updated guidance. 

Our planning service, developers and landowners will then use the updated guide to make sure extensions and alterations fit the needs and aspirations of everyone involved with good design.

The updated guidance will replace the existing supplementary planning document (SPD12) and become a material consideration in planning decisions.

Although the SPD will not make new or change existing planning policies, the council will use it to help achieve those policies – for example in building new high quality and accessible homes with usable outside space and to complement ‘place-making’ policies that aim to create attractive and successful public spaces.

Find out more about supplementary planning documents.

Planning policies are set out in the City Plan Part 1 and City Plan Part 2. The City Plan Part 2 is currently under preparation. Find out more about the City Plan Part 2.


Talking to a wide range of stakeholder groups in the city will provide another opportunity for local people to inform design priorities so that we can reflect the aspirations of different communities in the guidance.

For more information please email

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