Energy Efficiency in Historic Buildings
Historic Buildings and Energy Efficiency
Retaining historic buildings in use is inherently sustainable as it avoids the consumption of building materials and energy and the generation of waste from the construction of replacement buildings. It is however acknowledged that historic buildings may be less energy efficient than new buildings.
Where energy efficiency proposals would have a potentially harmful impact on an historic building the council will wherever possible help the owner or occupier to identify feasible solutions that deliver greater energy efficiency but with less or no harm to the historic building or its setting. Such improvements should avoid the loss of historic fabric and features and should be reversible.
In considering improvements for energy conservation it is important to remember that buildings of traditional construction perform very differently to modern buildings. The fabric of a traditional building needs to ‘breathe’, so that moisture within walls etc. (from rising damp, driving rain or condensation for example) can be released through evaporation. Modern impermeable building products can obstruct this process and lead to moisture being trapped inside, causing damage to the building. This can be worsened where ventilation has been reduced.
The council has produced planning guidance on retrofitting issues for houses in conservation areas as well as separate technical guidance specifically on external wall insulation. Please see PAN09 for Householder guidance on energy efficiency and PAN08 on External wall insulation.
Planning permission may be required for energy efficiency improvements and you should always check with the Planning service. If your property is a listed building then Listed Building Consent will be required for most energy efficiency works, including internal works such as internal wall insulation.
Energy Saving Measures will likely affect the fabric of historic buildings. The council’s policy on works that affect historic fabric, such as replacement windows, can be found in SPD09 Architectural Features. Historic England also provide advice on works to windows in historic buildings.
Historic England provides advice on generating energy in older houses, including solar panels, wind turbines and other types of energy generation.
The council’s policy on solar panels can be found in SPD12 Design Guide for Extensions and Alterations. Please note that the guidance in this document does not apply to listed buildings; in such cases please contact the Heritage team for advice.
Energy Performance Certificates (EPCs)
An Energy Performance Certificate (EPC) is not required in respect of listed buildings or historic buildings in designated conservation areas where “compliance with minimum energy performance requirements would unacceptably alter their character or appearance”. Government guidance on this can be found in respect of dwellings here https://www.gov.uk/government/publications/energy-performance-certificates-for-the-construction-sale-and-let-of-dwellings and in respect of non-dwellings can be found here https://www.gov.uk/government/publications/energy-performance-certificates-for-the-construction-sale-and-let-of-non-dwellings--2 The guidance provides examples of the types of works that are likely to be considered unacceptable.
Whist this guidance states that an EPC is not required if it would result in unacceptable alterations, it may be the case that it is necessary to get an EPC in order to find out whether ‘unacceptable’ works are in fact required. The guidance provides typical examples of likely unacceptable works but we would be happy to advise on the likely acceptability of any specific works that an EPC may require to a particular property. Please note that if a historic building is not listed but is within a conservation area internal alterations to improve energy efficiency can be carried out without the need for any planning approval.
Other sources of guidance and information
There are a number of other sources of information and guidance on energy conservation in historic buildings available on the internet:
The council’s General Housing Team provides information on a number of energy saving measures, sources of information and funding avenues.
The Sustainable Traditional Buildings Alliance provides guidance on retrofit measures relating to walls, roofs, floors, windows, doors and chimneys. Their interactive guidance wheel allows the user to customise the context and select thermal upgrading measures. This then shows various issues and possible risks to consider before installing such measures.
Other useful sources of information from other parts of the country are Warmer Bath [1.7mb] by the Bath Preservation Trust and the Centre for Sustainable Energy and guidance documents from the City of Westminster.