Parnham House, a Grade I-listed 16th-century manor in Dorset, has been at the centre of a high-profile planning debate. The house had major improvements by Nash in the early C19th, but these suffered very extensive damage from a fire in 2017. Its new owner proposes building 83 homes across 25 acres of parkland and meadow along the River Brit to fund its restoration.
This area lies outside Beaminster’s development zone and within the Dorset National Landscape (formerly AONB), a legally protected landscape. Dorset Council’s management plan for protecting this area of national significance has 13 objectives and 70 policies aimed at preserving its natural beauty, wildlife, and cultural heritage.
Under ordinary planning rules, major housing would be refused. Parnham’s plans rely on being allowed an exception called “Enabling Development” (ED). This is where housing normally not permitted can gain consent from the council planners if it secures the future of a heritage asset.
The National Planning Policy Framework states that councils must weigh whether the public benefits of restoration outweigh the public harm from departing from planning policies.
In Parnham’s case, reports suggest their proposals for this large private housing estate would contravene at least 60% of the council’s DNL policies, making approval exceptional. Their plans are also unusual since Dorset Council policy requires affordable housing schemes where 10 houses or more are proposed; 35% on brownfield sites and 50% on greenfield sites.
Historic England (HE) and Natural England (NE) are key regulators here.
- Historic England requires rigorous assessment to ensure Enabling Development is necessary, proportionate, and legally safeguarded, including financial oversight, building viability, and long-term management. They emphasise that it must only be considered as a last resort, after all other options have been considered and shown to be not available.
- Natural England protects the National Landscape area. The purpose of the National Landscape designation is to conserve and enhance its natural beauty and heritage. It ensures any development will not compromise biodiversity or the landscape. The new 2023 law requires any such development must actively improve the landscape and biodiversity.
Five strict prior tests from HE and NE must be met before consideration, including last resort, cost justification, legal agreements, future financial viability, and compliance with laws enhancing environmental protections.
The process involves careful planning appraisals, sensitivity analyses, and binding agreements controlling the flow of development funds into the restoration. Even if these tests are met, the core decision for the Council’s Planning Committee of 12 councillors is to judge whether the alleged public benefits clearly outweigh the public harm such as impacts on wildlife and rivers, on green space amenity use and heritage, and on local facilities and infrastructure.