The need for housing is always present in the UK and continually growing as population numbers rise quicker than properties can be built. In the rush to meet demand, the ecological and environmental consequences can often be overlooked. This can be particularly crucial when several development projects in close proximity are combined into a fully connected multi-phase development, which poses the risk of severing habitats and species populations. This is particularly true for habitat restricted and less mobile species such as the dormouse and great crested newt, which cannot cross larger roads or some developed areas.

When an individual piece of land is sold for housing development, the ecological mitigation measures are often clear. Retain a section of the land to be maintained or enhanced for wildlife in the area and ensure that connectivity to surrounding habitats is not removed. Alternatively, for small numbers of species, there is the option of translocation to a conservation area already maintained for the benefit of wildlife where further enhancements are then introduced to cater for the sudden growth in a population. The former choice is always preferred.

With multi-phase developments, where several individual pieces of land are over time combined and connected to create one large development, the challenge of retaining land and maintaining connectivity becomes more difficult as areas left untouched during one phase are being ear-marked for development at a later stage, or indeed become isolated due to the loss of connecting habitat.

The Ecology Co-op are currently working on a multi-phase development consisting of three large parcels of land that will provide up to 1500 houses in West Sussex. This can only be achieved successfully from an ecological point of view through landscape level planning for ecology design in collaboration with the client. In order to balance development and conservation to the benefit of both, a mitigation hierarchy of avoid, minimise, restore and offset is used to minimise impacts. However, when implemented on a project by project basis the cumulative impacts of multiple individual development projects are underestimated[1].

Landscape-level conservation planning is the process of locating, configuring and maintaining areas that are managed to maintain viability of biodiversity and other natural features[2]. In the context of our West Sussex project this involved identifying key areas for protected species in and around all three project sites to implement a strategy that would maintain and enhance important habitat areas and provide connectivity on a large scale so that populations of dormice and bats will be integrated across all three sites.

Additional plans for green infrastructure within the three development projects allow new migration routes for bats to be added which are intertwined by those already in place in the surrounding enhanced habitats. Features such as green roofs, living walls and wildflower gardens fed by surface run-off are beneficial in their own right, however by viewing all three project areas as a single entity, these features can become inter-connected to allow wildlife to be integrated within the development as well as around it, minimising the impact of the multi-phase development and providing a net positive impact in biodiversity. As we often point out to our clients – people love to see wildlife on their doorstep!

[1] Kiesecker JM, Copeland H, Pocewicz A and McKenney B. 2009. Development by design: blending landscape-level planning with the mitigation hierarchy. Front Ecol Environ 2010; 8(5): 261-266.

[2] Pressey RL and Bottrill MC. 2008. Opportunism, threats, and the evolution of systematic conservation planning. Conserv Biol 22: 1340-45.