Heritage Works for Housing: The Interface of New and Old

The Role of New Build Elements

The reuse of historic buildings can present viability challenges and therefore require an element of new build to "cross-fund" the works to bring the historic building into a long-term viable use. It may also be that the site interfaces with brownfield land and a new build residential element is the most suitable use of the land.

Planning applications for residential development may require a viability statement. Even if a proposal does comply with the Local Planning Authority’s affordable housing policy, it may be necessary to submit a viability statement to demonstrate the need for a new build element that may cause an element of harm to the historic building.

There are also instances of Enabling development which has specific meaning in the historic environment, "enabling development is development that would not be in compliance with local and/or national planning policies, and not normally be given planning permission, except for the fact that it would secure the future conservation of a historic building" It is used to directly assist with addressing the conservation deficit which is defined as, "The amount by which the cost of repair (and conversion to Optimum Viable Use if appropriate) of a historic building exceeds its market value on completion of repair and conversion, allowing for all appropriate development costs".

It is important to understand the viability role of the new build element when framing the planning and listed building case. For enabling developments there is typically much greater scrutiny.

Funding and phasing strategies need to be cognisant of the different elements of the building. On occasion, a condition of planning may be that the new build element cannot be occupied until works have commenced on the listed building.

Form of the New Build

Design development exercises are likely to be required to demonstrate the build element has been sensitively designed.

It is anticipated that any new build element would be subject to current building regulations. Therefore design development should robustly ensure that all necessary regulations can be met.

Extension

All extensions need to give specific attention to the structural integrity of the historic building and the interventions that may be required to facilitate that extension. These interventions need to be sensitively designed with consideration to areas of higher heritage significance.

Additionally, consideration needs to be given more broadly to the impact on townscape and other amenity considerations for surrounding uses. This includes, for example, the potential impact on neighbouring privacy, noise, and daylight.

New Build

Where new build elements are standalone, then additional consideration needs to be given to whether the development impacts the setting, and thereby significance, of an existing historic building; and whether any resultant harm can be justified.

Case study: Wood Street Town Houses

The Wood Street Townhouses development consists of the conversion of a non-designated heritage asset (a former Mission building) and new build element that is located within a conservation area and adjacent to a Grade I listed building.

The existing layout of the non-designated heritage asset was challenging and achieving an optimal layout was constrained by the existing building envelope and door and window positions. In addition, as a smaller scale build, there were challenges to ascertain abnormal costs or benefit from economies of scale. As such it was necessary to have the new build element to support the overall viability of the scheme, albeit the proposals were brought forward across two separate planning permissions. 

The new build element was situated on land previously used for car parking, which was no longer required given the site's highly sustainable city centre location.

The two new-build townhouses helped to create a viable development that allowed for positive outcomes to be achieved overall. The Wood Street Townhouses represent an effective use of an existing non-designated heritage asset, delivering high quality residential uses in a constrained city centre location, on a small bespoke scale.