Open Letter to the Leader of Sevenoaks Council

Dear Cllr Maskell

The Government’s housing targets require 17,460 new homes to be built in Sevenoaks by 2042. That's around 1,164 homes a year; a 63% increase on the previous housing requirement for Sevenoaks.

The Local Plan is vital to maintain control over this development. But it needs to be sustainable, deliverable and sound.

That’s why we are asking: is this plan actually capable of delivering this level of growth without unacceptable impacts on the environment and infrastructure? 

We call on Sevenoaks District Council to review and strengthen the proposed Sevenoaks Local Plan in light of the findings of its own July 2026 Sustainability Appraisal, before the Plan is submitted for examination.

The Sustainability Appraisal identifies important benefits from the proposed Plan, including a significant positive effect on economy and employment. But it also identifies significant environmental costs and a number of areas of uncertainty.

According to the Council's Sustainability Appraisal, the proposed Plan is predicted to have:

• a significant negative effect on landscape;
• a moderate or uncertain negative effect on biodiversity;
• a moderate or uncertain negative effect on climate change mitigation;
• a moderate or uncertain negative effect on transport; and
• a moderate or uncertain negative effect on water.

The appraisal concludes that the remaining topics are broadly neutral, including air quality, climate change adaptation, communities and health, the historic environment, homes, and land, soils and resources.

We believe these findings deserve a full and transparent response before the Plan proceeds to examination.

We are particularly concerned about landscape

The Sustainability Appraisal identifies landscape as the Plan's one significant negative sustainability effect.

A major element of the proposed strategy is the approximately 2,600-home Pedham Place development, which is within the Kent Downs National Landscape.

The Sustainability Appraisal acknowledges arguments in favour of Pedham Place, including its potential to accommodate substantial development in one location and opportunities for mitigation. However, it also identifies landscape concerns and concludes that landscape remains a significant negative effect for the Plan as a whole.

We therefore ask the Council to demonstrate clearly why the scale and location of development proposed at Pedham Place represents an acceptable balance between meeting housing needs and protecting the District's nationally important landscape.

We are worried about climate change

The Sustainability Appraisal predicts a moderate or uncertain negative effect on climate change mitigation.

It specifically notes that the proposed approach does not require standards of built-environment decarbonisation beyond minimum Building Regulations requirements.

The appraisal also states that an earlier recommendation - that further work should ensure decarbonisation opportunities are realised through strategy and site selection - has not fed through strongly enough.

We therefore call on the Council to explain how the Plan will adequately address climate change mitigation and whether stronger policies are required before the Plan is finalised.

We are concerned about transport

The Sustainability Appraisal identifies transport as a moderate or uncertain negative effect and specifically identifies concerns associated with Pedham Place.

At the same time, the appraisal recognises that concentrating development in strategic locations can have advantages for strategic transport planning, while dispersed development can create additional travel and make infrastructure planning more difficult.

We therefore call on the Council to demonstrate that the transport impacts of the proposed growth strategy can be satisfactorily mitigated and that the necessary infrastructure will be delivered alongside development.

We are concerned about water and the Rivers Darent and Eden

The Sustainability Appraisal identifies inherent uncertainties regarding water resources and wastewater treatment and predicts a moderate or uncertain negative effect under the proposed Plan.

Given the scale of planned development, we believe the Council should demonstrate clearly that sufficient water resources and wastewater infrastructure will be available to support the proposed growth without unacceptable environmental consequences.

We are worried about biodiversity

The Sustainability Appraisal recognises biodiversity as a strategic constraint on growth within the District.

Although it identifies Pedham Place as a location with relatively limited biodiversity constraints compared with some alternatives, it also identifies an outstanding concern regarding Open Mosaic Habitat and questions whether sufficient space will remain for onsite mitigation given the proposed scale of development.

We therefore call on the Council to ensure that biodiversity impacts are avoided wherever possible, rather than relying solely on mitigation after development has been selected.

We believe the alternatives deserve proper consideration

The Sustainability Appraisal does not conclude that the Council's preferred Scenario 1 is objectively the best-performing option across all sustainability considerations.

It states that Scenario 1 ranks first under the greatest number of sustainability topic headings, but also identifies Scenario 6 as producing the greatest number of predicted positive effects.

Importantly, the appraisal states that alternative Scenarios 4 and 5 could be preferred if greater weight is given to housing, landscape and transport objectives. It also notes that these alternatives, which involve a greater contribution from smaller sites, could improve early housing supply and reduce the risk of the Council failing to maintain a five-year housing land supply.

The appraisal therefore demonstrates that there are genuine choices about how the District's housing needs could be accommodated.

We call on the Council to explain transparently why Scenario 1 is considered preferable on balance, particularly given its significant negative landscape effect and the moderate or uncertain negative effects identified for biodiversity, climate change mitigation, transport and water.

We are not calling for housing needs to be ignored

We recognise that Sevenoaks faces significant housing need and that the Council must plan positively for development.

The Sustainability Appraisal itself recognises that simply reducing growth can create other problems, including unmet housing need, pressure for development elsewhere and the risk of an insufficient housing supply.

Our concern is therefore not simply the amount of development proposed.

Our concern is whether the chosen strategy represents the most sustainable, deliverable and environmentally responsible way of meeting those needs.

The Council's own evidence shows that this is a matter of judgement and balance rather than a question with only one possible answer.

Our request

We therefore call on Sevenoaks District Council to:

1. Fully acknowledge and respond to the significant negative landscape effect identified by its July 2026 Sustainability Appraisal.
2. Address the moderate or uncertain negative effects identified for biodiversity, climate-change mitigation, transport and water.
3. Demonstrate that the infrastructure required to support the proposed scale of growth will be delivered alongside development.
4. Review whether stronger climate change mitigation requirements are necessary, particularly in light of the Sustainability Appraisal's finding that the Plan currently produces a moderate or uncertain negative effect in this area.
5. Ensure that the environmental impacts of Pedham Place are properly addressed, including landscape, biodiversity and transport impacts, before the Plan is finalised.
6. Explain why Scenario 1 is considered justified on balance when the Sustainability Appraisal identifies credible alternative scenarios which may perform better against particular objectives, including landscape, transport and housing delivery.
7. Make any necessary changes to the Local Plan before submission for examination where the evidence demonstrates that the Plan could be made more sustainable, deliverable or sound.

The Sustainability Appraisal states that the purpose of the process is to help minimise adverse effects and maximise positive effects. It also makes clear that the appraisal and consultation responses must be taken into account when the Plan is finalised.

We therefore ask the Council to listen to the evidence, respond to the concerns identified by its own Sustainability Appraisal, and ensure that the Sevenoaks Local Plan delivers the homes and economic opportunities the District needs without accepting avoidable environmental damage or infrastructure pressures.

We call on Sevenoaks District Council to make the necessary changes before the Local Plan proceeds to examination.

This letter was written by Sevenoaks Green Party and is endorsed by all those who have signed below.