Mansard roof proposals within Driffield Road and Medway conservation areas

We have been working with residents to enable a more permissive approach to proposals for mansard roof extensions within the Driffield Road and Medway conservation areas. This is because many residents have told us that they would like to have greater flexibility to extend their homes to enable them to accommodate their families without having to move away from the area. Some residents, however, told us that they were concerned that mansard roofs could be harmful to the character and appearance of the two conservation areas.        

The National Planning Policy Framework (NPPF), the government’s overarching set of planning policies, states that, where a development proposal such as a mansard roof extension would result in harm to the historic environment, that harm must be weighed against the public benefits of a proposal. Harm to the historic environment can be outweighed if a development proposal demonstrates that it would deliver sufficient public benefit. We have, therefore, looked at ways that the harm to the historic environment caused by mansard roof extensions could be mitigated and balanced with suitable public benefits.  

We have now published revised character appraisals and management guidelines for Driffield Road and Medway conservation areas. These documents contain details on how a mansard roof can be sympathetically designed to ensure that harm to the special character and appearance of the conservation areas is minimised. Planning applications for mansard roof extensions will be required to demonstrate how they comply with this design guidance. 

We have also published façade enhancement guidance for the two conservation areas. This guidance describes works that can be undertaken by homeowners, alongside a mansard roof extension, that will improve the appearance of their properties. These façade enhancements can help to improve the character of the conservation areas, and will help to mitigate the harm caused by mansard roof extensions. These documents were subject to public consultation and formally adopted by the council at a Cabinet meeting on 27 June 2017. The documents can be viewed below: 

In addition to adopting the guidance documents above, Cabinet also agreed that planning applications for mansard roof extensions in these two conservation areas should also make a financial contribution to a streetscape enhancement fund.  Financial contributions will be secured through a legal agreement as part of the planning application process. The fund will be used to deliver heritage related streetscape improvements to the public realm that will also help to mitigate the harm caused by mansard roof extensions. We are currently exploring options for streetscape improvement projects to be delivered by the fund, details of these will be published here in due course.    

In order to deliver sufficient public benefit to be considered acceptable, planning applications for mansard roof extensions will be expected to deliver both façade enhancements and make a contribution to the streetscape enhancement fund. 

If you require further advice about making a planning application for a mansard roof extension you may wish to use our pre-application advice service.