Nutrient neutrality is one of the most complex of those risks — often emerging late, creating delay and affecting viability in ways that are difficult to model at the outset.

Environmental Delivery Plans (EDPs) are being positioned as a solution. The question is whether they will work in practice.

Greenshank has been trying to get pragmatic approaches to nutrient neutrality (NN) since our inception. Back in 2023 we penned a levy approach to NN for Matthew Pennycook while the Levelling Up and Regeneration Act (LURA) was making its way through the House of Lords.

Elements of that thinking now appear to have translated into policy in the form of Environmental Delivery Plans (EDPs).

What is an EDP?

The government’s proposed Environmental Delivery Plans (EDPs), led by Natural England, shift nutrient neutrality from a fragmented, site-by-site burden to a strategic, catchment-wide delivery model.

Rather than requiring each development to design and implement its own mitigation, EDPs establish a coordinated programme designed to reduce nutrient loads at scale, with credits issued against that delivery.

For developers and funders, this should provide a greater degree of certainty. By purchasing EDP-backed credits, a scheme can demonstrate compliance with the Habitats Regulations without taking on direct delivery risk, with responsibility for performance sitting with the plan operator. In theory, this should reduce planning friction, programme delays and technical complexity.

We have been privy to various versions of the EDPs, and there have been some fundamental changes to our original levy approach. These are likely to reduce the effectiveness of the policy if left unchanged.

Why we recommended a levy

The levy approach was designed to enable the delivery of housing across impacted catchments without undermining scheme viability. If EDPs do not achieve this, they will fall short of their core objective.

As currently structured, EDPs are likely to have only a marginal impact, supporting some developments in some areas rather than unlocking supply at scale.

In areas with a functioning mitigation market, developers are unlikely to see a meaningful advantage over the current system. Private mitigation is often already available and competitively priced.

•   The Finance Professional Show 2025: The Video
•   Planning policy must catch up with how people actually live
•   Why net lending maximises usable funds in development finance

The exception is typically geographically constrained sites — often smaller schemes located at the top of catchments — where existing rules restrict access to mitigation. Proposed relaxations to geographic constraints may improve outcomes here.

One of the core issues we identified is the approach to pricing. The draft we saw includes four pricing brackets depending on the effectiveness of nutrient removal at the relevant wastewater treatment works: £5,000, £6,000, £32,000, and £64,000 per house.

At the upper end, this is likely to render schemes unviable.

In practice, most new homes will connect to newer treatment works with better nutrient stripping technology, meaning the highest-cost scenarios should represent a relatively small proportion of demand. This creates an opportunity for a levy to spread the burden across development, ensuring that schemes facing higher mitigation requirements remain viable. This mechanism does not appear in the latest draft we have seen.

In catchments where a mitigation market already exists, the primary opportunity for EDPs is to drive down costs. However, the current design — procuring multiple years of mitigation in a single round — risks distorting the market by reducing competitive tension and weakening price discovery.

A more effective approach would be structured, annual reverse auctions, with transparency on volumes and clearing prices. Any shortfall should be rolled forward, maintaining continuity without overcommitting capital. This would support competition, more efficient pricing, and better allocation of supply.

In areas where there is no existing supply, the benefits of EDPs will be greater and could release a significant portion of constrained housing. However, the pricing issue must still be addressed, and without annual procurement, costs are likely to remain high.

Finally, EDPs must be both scientifically robust and demonstrably deliverable. Without expanding the range of approved mitigation methodologies — particularly approaches such as river restoration — it will not be possible to generate sufficient supply in many constrained areas. This creates a risk of challenge, which could further delay development.

Incorporating additional, proven methodologies would strengthen both the resilience and scalability of the policy.