For people lucky enough to buy into new housing developments, it is doubtful that the quality of the landscaping or local biodiversity is a major consideration in their decisions. Bare earth often seems to our imagination like a good place for a fresh start.
But it is a fact that the most biodiversity-rich places are often those that are old, untidy and neglected, not those that are strimmed into bland submission. In urban areas, derelict sites overrun with scrub and ivy are usually more important to biodiversity than roadside verges sprinkled with wildflowers. Mature hedgerows can support literally hundreds of distinct, native species, but hedgerows are usually the first things to go when the builders move on-site.
Nature thrives where people leave things alone, so derelict sites, old farm buildings, stone walls and other neglected areas often provide perfect habitats for birds, bats, wildflowers and trees.
Land set aside for development may not be actively used or farmed for many years. It is often the case that pockets of woodland scrub, wetlands or heath on such land may be biodiversity hotspots without anyone particularly noticing – until the diggers arrive to clear the site. Disturbing water sources such as streams, ponds and rivers as part of the construction activity could also have serious negative consequences for habitats downstream.
READ MORE
With 300,000 new housing units planned by 2030 (or 50,000 new units annually) under the Government’s housing strategy, the very act of procuring sites and developing these areas for housing has the potential to be enormously destructive to local biodiversity, which is already under extreme stress.
Planting regimes on new housing estates or at apartment complexes are unimaginative and do not contribute to biodiversity in most cases, whereas it only takes a tiny area to establish pocket parks and pocket forests
Yet our planning system only requires a comprehensive environmental impact report for large-scale housing developments and infrastructure, which means that smaller developments often do not require a standard ecological assessment.
The Government’s 4th National Biodiversity Action Plan (2023-2030) adopts a “whole-of-Government, whole-of-society” approach. Under this framework, all State departments and public bodies are bound by a legal duty to integrate nature conservation into their policies, budgets and operational plans. One of the requirements is to give greater weight to the loss of non-designated habitats – such as semi-natural grasslands, trees and local wetlands – during the planning assessment stage.
If planning authorities and developers adhere to this goal, all new construction, regardless of what is being built, should enhance the local environment, restore existing habitats and create new corridors for flora and fauna.
In practice, however, unless specific features are marked for protection in some way, developers will likely want to clear (ie bulldoze) the site as much as possible before construction begins. And construction works often have a big impact, with heavy vehicles that compact the soil, earth moving and the diversion of streams literally destroying habitat.
Practitioners and agencies interviewed for a new report by the Irish Green Building Council (IGBC) said “most developments slip through [the assessment] net”, leaving biodiversity largely unaddressed in many projects, particularly smaller developments.
The report found a lack of enforcement further negatively affects outcomes for nature and biodiversity. Interviewees stated that measures submitted at the planning stage are often not followed through at the construction stage or in long-term management plans.
The “taking in charge” process and public green space management strategies vary significantly across local authorities and often result in nondescript, barren roadside verges and random spaces that seem without function. Planting regimes on new housing estates or at apartment complexes are unimaginative and do not contribute to biodiversity in most cases, whereas it only takes a tiny area to establish pocket parks and pocket forests, if designed into the schemes at the outset.
Local-authority maintenance regimes can also unintentionally affect outcomes for biodiversity, as measures implemented at the planning stage, such as meadow management for grassland, are gradually changed over time with excessive grass-cutting and use of herbicides.
[ Government pushes for apartment living in desperate bid to deliver housingOpens in new window ]
The IGBC report makes a series of recommendations for public authorities and the building sector to consider “nature-led developments” as the goal from the outset. This would ensure the overall ecological impact of a project “results in a demonstrable enhancement of biodiversity and supports long term ecological resilience, accounting for both direct site‑level impacts and indirect embodied ecological impacts”.
“This should be achieved by recognising existing site conditions, implementing the mitigation hierarchy (avoid, minimise, restore, compensate), prioritising like‑for‑like nature restoration where possible, enhancing ecological connectivity, and securing long‑term management and monitoring,” it says.
In Northern Ireland, developers are required to complete a biodiversity checklist which gives the planning authority the necessary site information to then request a more detailed ecological survey and mitigation measures if needed. We would do well to follow this approach, given the scale of construction that is planned over the coming years.
