A tariff-based plan to protect East Suffolk's habitat sites and conservation areas, including those on the Felixstowe peninsula, from the impacts of increased housebuilding has been improved to help developers understand their obligations.

East Suffolk Council's cabinet last night approved a supplementary planning document as part of its strategy to avoid disturbance on key natural sites by increased numbers of people moving into the area.

It features a tariff which housing developers must pay. It will fund the necessary measures to protect conservation sites and wildlife habitat hotspots from the increased numbers of people expected to use those areas for walks and recreation

That applies on housing developments within 13kilometres of a habitat site, set at £121.89 per house around the Stour and Orwell and Deben Special Protection Areas, with £321.22 for all other habitat sites.

Councillor David Ritchie, cabinet member for planning and coastal management at East Suffolk's Conservative administration, said: "The coast, heaths and estuaries of Suffolk are internationally recognised for their wildlife habitats.

"We have these designated sites but we also have the ambition in both our local plans to build quite a large number of homes.

"If we are building houses near these designated sites, we have to consider the effects of housing on these sites. With more houses, we have more people going for country walks, bird watching etc.

"For every house built near the designated sites there will be a charge, and the money is used to provide facilities in the sites."

He added: "We do take protecting habitat sites extremely seriously. They are important to Suffolk and they are important to this council."

Those contributions are required around Special Areas of Conservation – mostly heaths and marshes, Special Protected Areas which mostly protect birds' nesting sites and wetlands.

While the strategy is already in place, the supplementary planning document provides more clarity to developers, outlines how they will be implemented and addresses the key issues.

The council said the tariff is calculated on estimates of projected housing growth and the number of new residents that will generate.

It is also based on the financial costs of necessary improvement measures such as employing wardens, improving footpaths or upgrading signs, with that cost shared across the number of new homes.

Green group leader Caroline Topping said measures needed to be in place for the long term.

Labour's Louise Gooch said she hoped it would encourage the buyers of those new homes to understand the contributions made to their nearby wildlife spots and engage in looking after their community.