Guide: Nutrient Neutrality & Development
Nutrient neutrality was introduced with good intentions: to protect sensitive rivers, wetlands and habitats from excess nitrogen and phosphorus. No one in the planning or development sector disputes that our waterways need better protection. However, the way the policy has been interpreted and applied has created an administrative tangle that does little to solve the underlying environmental problem, while bringing many small and medium-sized housing schemes to a standstill.
What Nutrient Neutrality Aims to Do
The concept stems from the Conservation of Habitats and Species Regulations 2017. Where development could increase nutrient loading in catchments feeding protected sites, the Local Planning Authority must ensure that any proposal is “nutrient neutral” — meaning that the scheme does not add to the overall burden on the habitat. In principle, this sounds reasonable. In practice, it has become another blunt regulatory tool that treats every new home as if it were a major polluter.
Where the Policy Falls Down
1. The wrong source is being targeted
The overwhelming majority of nutrient pollution comes from agriculture and wastewater treatment, not from the drains of new homes. Yet, new housing has become the focus of the restrictions, largely because it is easier to control through the Planning Permission process. This shift of responsibility may simplify regulation on paper, but it does little to address the main causes of river pollution. Developers are being asked to fix problems that originate far upstream both literally and figuratively.
2. Mitigation is often unworkable
Theoretically, a developer can offset their impact by creating or funding mitigation elsewhere in the catchment. In our experience, such options are rarely available, poorly defined, or financially unviable. Some areas have established nutrient credit schemes, but they are patchy and inconsistent. Many Local Planning Authorities still have no clear pathway to approve mitigation at all. As a result, otherwise sustainable developments are delayed indefinitely while agencies and councils debate methodologies and metrics. In our opinion, there should be a national credit scheme ran by central government.
3. Disproportionate impact on smaller sites
Larger developers can sometimes absorb the cost of surveys, consultants and mitigation land. For smaller builders or self-builders, the same requirements can render a modest project unviable. In some catchments, a single dwelling now triggers a full nutrient calculation exercise even when the environmental impact would be negligible. We have seen situations where just two extra WCs discharging into the public sewers has triggered NN mitigation. The result is that the policy penalises precisely the kind of small-scale, sustainable, infill development that the planning system is supposed to encourage.
The Legacy of Water Company Privatisation
Much of the nutrient neutrality issue can be traced back to decisions made decades ago during the privatisation of the water industry. The fragmented, profit-driven model that followed has left England with under-invested wastewater infrastructure, outdated treatment works, and a regulatory framework that too often rewards dividends rather than performance.
Instead of upgrading systems to meet modern environmental standards, many water companies have relied on combined sewer overflows and outdated discharge consents allowing untreated waste and nutrient-rich effluent into rivers at alarming levels.
The result is that housing development, already subject to rigorous planning controls, is being used to compensate for decades of missed investment by the privatised utilities. It is an imbalance that makes little sense to those working on the ground.
Our View
At PAA Ltd, we support genuine environmental responsibility and practical sustainability in development. However, nutrient neutrality as currently applied feels more like a bureaucratic exercise than an effective environmental policy.
Until Government and its agencies address the failures of the privatised water system or create an efficient centralised NN credit system, nutrient neutrality will continue to create delay without delivering the cleaner rivers it set out to achieve.
Nutrient Neutrality
The concept of nutrient neutrality emerged in England around 2019, following European Court of Justice and UK court rulings on the Habitats Directive. The key turning point was the 2018 “Dutch Nitrogen” cases in the Netherlands (Coöperatie Mobilisation for the Environment), which established that competent authorities could not approve projects adding nutrients to already polluted protected sites unless strict mitigation was guaranteed.
In response, Natural England issued guidance in June 2019, advising Local Planning Authorities to adopt a similar precautionary approach. From that point, any proposal that might increase nitrogen or phosphorus in designated sites required a Habitats Regulations Assessment and proof of “nutrient neutrality.”
At that time, the Conservative Government under Prime Minister Theresa May, with Michael Gove as Secretary of State for Environment, Food and Rural Affairs, oversaw the framework that allowed this policy direction. Gove’s successor, George Eustice, later reinforced the approach under Boris Johnson’s administration, positioning it as part of the post-Brexit environmental strategy.
Initially, only a handful of catchments were affected, but the policy widened rapidly between 2020 and 2023, as more habitats were assessed as being in “unfavourable condition.”
By 2023, under Rishi Sunak’s Government, more than 70 Local Planning Authorities in England were subject to Natural England’s nutrient neutrality advice — a situation that had become a major national constraint on housing delivery.
