Navigating Legal Challenges in Property Development – Hillside Parks Limited v Snowdonia National Park Authority

21 May

The original plan for the development project in Snowdonia, originally approved in 1967, allowed for the construction of 401 houses according to a specific ‘master plan’. Over the years, developers only built some houses according to the original approval. Instead, a series of subsequent permissions, known as ‘drop-in permissions,’ were granted for development under the original consent, and construction proceeded based on these new permissions.

This decision led to a significant legal question: did these ‘drop-in permissions’ deviate so much from the original master plan that they invalidated the original planning consent?

After reviewing previous decisions by the High Court and the Court of Appeal, the Supreme Court has now ruled. They determined that the houses and estate roads built so far do not align with the original master plan from 1967. As a result, because it is now physically impossible to complete the site as initially planned, any further development under the original 1967 consent is considered unlawful.

The key takeaway from this decision is clear: any new applications for development projects or amendments to existing plans need to be thoroughly reviewed and carefully considered to ensure they comply with the original master plan or updated planning permissions.

As a result of the Hillside Parks Limited v Snowdonia National Park Authority case and its implications on multi-unit permissions, developers and their advisers are unsurprisingly looking to protect current development sites, as well as their funders and plot purchasers, which could now be at risk following the ruling.

The Financial Security Benefits of Indemnity Insurance

Our Legal Indemnities team recently received an enquiry about an ongoing residential development where a small section of the site had been replanned, potentially causing issues under the Hillside decision. Leveraging our access to specialist insurers, we successfully secured a bespoke policy to cover losses arising from an enforcement notice. This policy provides financial security to the insured, financial investors and future plot owners should the original planning permission be deemed unlawful due to the replanning. The policy covers the following losses:

  • Damages, compensation, costs and expenses awarded against the insured
  • Reduction in market value
  • Cost of any alteration, demolition and reinstatement of the property
  • Costs in defending and remedying a claim, including settlements
  • Legal and professional fees incurred

Need Advice?

We understand that the ruling in the Hillside Parks Limited v Snowdonia National Park Authority case has raised significant concerns for developers and plot purchasers involved in extensive, phased multi-unit developments, especially regarding the validity of planning permissions. It is crucial to understand the potential risks and ensure adequate protection. Additionally, consider how these issues might impact transactional deadlines and any plans you have for the property. Proper preparation can help mitigate uncertainties and safeguard your interests.

If you have any questions, please do not hesitate to contact Head of Legal Indemnities Sarah Jones on 02920 858602 or at