Environmental Net Gain

As well as setting ambitious, and deliverable, targets for our buildings, in terms carbon use in operation, and embodied carbon, we will adopt the latest thinking in Environmental Net Gain (ENG) in order to take care of the natural environment, long term.

Our commitment to creating an ENG will be in addition to the local planning policies that guide enhancements to landscaping and biodiversity.

We will work with local stakeholders to establish a partnership area for our ENG strategy. Our first step will be to identify natural assets, their related ecosystem services (e.g., pollination, fresh water, air quality) and associated welfare benefits. Or – put another way – we are looking to identify existing habitats and to clearly understand what value they bring to people and planet.

Our approach is built on supporting natural capital and making a measurable contribution to improving the natural environment. The baseline information that we will gather will be used to help us measure and evaluate the current condition of natural assets and over time implement evidenced based strategies – in response to local priorities – to create net improvements in both environmental and social wellbeing.

At present the site is dominated mostly by uneven and unfriendly concrete slabs and tarmac, with some low-quality shrubs, and areas of grassland. Our scheme will increase the amount of green space by around 200%. We plan to do this by removing large areas of hardstanding to significantly expand the amount of green space.


We understand the importance of trees to the environment, air quality and the setting of Castle Park and the surrounding area. This is why, as part of our design process, we have spoken with the Bristol Tree Forum and Friends of Castle Park, and consulted with them on our plans. Through these discussions we have managed to improve our tree retention strategy and put together a compensation package which more than meets the Bristol City Council’s requirements.

Feedback from local representatives on our tree retention strategy has guided our overall approach to redeveloping the site. Including:

  • Moving Building C to retain the trees along Wine Street.
  • Not building between building B and Castle Park to retain the London Plane trees.
  • Adjusting Building B and retaining Bridge Street to reduce the impact on the trees in this area.

St Mary le Port is surrounded by a range of mature, and middle-aged, London Plane trees planted in the 1960’s and 1970’s. Whilst the majority of trees, in and around the site, will be retained, the plans do mean that we have to remove 13 trees for a variety of reasons, including:

  • Two because of significant irreplicable impact to the ancient fabric of the church ruins – a third tree was removed by Bristol City Council in November 2020 due to the impact on the ruins.
  • One because of significant irreplicable impact to the ancient fabric of the medieval vaults.
  • Three Hawthorns due to their poor condition.
  • Five trees along Wine Street and High Street and two on the edge of the site adjacent to Castle Park, to enable the development, including enabling us to reintroduce the old streets.
Trees to be Removed & Retained

To compensate for the loss of the existing trees, we are committing to an extensive tree planting scheme on the site and across Castle Park. We plan to plant 60 new trees, which includes:

  • 12 trees in the public realm / streetscape
  • 8 trees along the new planted terraces down to the Floating Harbour
  • 40 trees in Castle Park

These new trees will be a variety of ages, size and species suitable for their location and to promote biodiversity and wildlife in the city.

Ecology and biodiversity

New planting will be incorporated throughout the site, with biodiverse roof terraces, green roofs, terraced planters at street-level and landscaped terraces down to the Floating Harbour.

The new buildings will have bird and bat boxes and the roof terraces will include Peregrine nesting boxes. We also plan to create hibernacula environments within the new elements of the ruins to attract insects and other mini beasts and the St Mary le Port Tower will be able to provide suitable environments for bats and House Sparrows.