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Thames Basin Heaths special protection area SPD

Read the Thames Basin Heaths SPA Avoidance Strategy 2017 SPD (PDF, 9 MB)

The Special Protection Area Strategy contains guidance for developers whose work could impact the Thames Basin Heaths SPA. It sets out restrictions for developments that could directly harm the SPA, and mitigation schemes for new residential development. These mitigation schemes are:

These mitigation schemes are:

  • Suitable Alternative Natural Greenspaces (SANGs) - new open spaces that attract visitors away from the SPA, and;
  • the Strategic Access Management and Monitoring (SAMM) project, which mitigates the impact of SPA visitors

SANG and SAMM are funded by tariffs that are based on the average number of people living in homes of different sizes.

The tariffs are updated every year at the end of March to take account of inflation. See the annual tariff update.

Special Protection Area Tariffs SPD

Read the Special Protection Area Tariffs 2024 Supplementary Planning Document (PDF, 465 KB)
This document should be read alongside the SPA strategy. It changes the strategy by:

  • updating the occupancy rates for new homes using data from the 2021 census
  • changing the SANG and SAMM tariffs using the new occupancy rates
  • changing how tariffs are applied to Houses in Multiple Occupation (HMOs)
  • clarifying how tariffs are applied to residential caravans and temporary developments.

We carried out a four-week consultation on the draft SPD in May and June 2024. You can view the draft SPD together with the responses that we received. (opens new window) 

We made the the decision to adopt the SPD on 5 September 2024. (opens new window) 

You may also wish to read our adoption statement (PDF, 125 KB) and consultation statement (PDF, 113 KB) consultation statement.

If you need a copy of the Special Protection Area Tariffs SPD 2024 SEA HRA Determination by email or post, you can reach us at

Posted copies will be charged at £5.00.

Special Protection Area Tariffs Calculator

We've prepared a calculator to calculate the correct SPA tariffs for:

  • schemes building multiple new homes
  • schemes converting homes to houses in multiple occupation
  • schemes building new houses in multiple occupation

Download the SPA Tariffs Calculator (Excel doc, 21 KB)

Read more documents relating to the Thames Basin Heaths Special Protection Area SPD: