Navigating the Intersection of Heritage and Sustainability 2024

24 June 2024

It is important to remember that original or historic window frames which contribute to the special interest of a building should not be replaced unless it can be clearly demonstrated that repair is not feasible.

Liza Konstantinova Planning and Heritage Advisor London

The integration of sustainable solutions and energy efficiency measures into heritage assets has been a long-standing endeavour across the sectorYet retrofitting historic houses continues to pose challenges, questions, and uncertainties. 

In November 2023Historic England issued the draft "Climate Change and Historic Building Adaptation" Advice Note (HEAN)aiming to address pertinent sustainability agendas within the sectorThis comprehensive guide aims to clarify what changes can be made to historic buildings to enhance energy efficiency and ensure carbon reduction while preserving their significance. The draft HEAN aims to help both property owners and local planning authoritiesfacilitating consistent decision-making when determining applications for planning permission and/or listed building consent. 

The draft HEAN reflects a more positive stance and shows some flexibility on retrofitting historic buildingsIt provides clear advice on insulation, draught-proofing, heating systems (including boilers and air source heat pumps), replacing or adapting windows, and installing solar panels, dispelling some of the myths around actions that can be permitted in a listed building or conservation area. While not exhaustive, it encompasses common interventions, based on more detailed technical advice provided by Historic England. 

Retrofitting Windows 

One noteworthy aspect of the draft HEAN pertains to their recommendations on retrofitting windows. For unlisted buildings situated in conservation areasthe installation of slim-profile double-glazed units is permitted development, provided: 

  • the installation respects the building's architectural integrity; 

  • the materials utilised match the appearance of the existing construction (with PVCu replacement windows being unsuitable due to visual and operational differences); and 

  • there are no other material alterations to the windows themselves. 

For listed buildings, listed building consent (LBC) remains necessary in most cases. Howeverthe draft HEAN adopts a more progressive stance and offers some flexibility concerning the retrofitting of historic windows: 

  • the installation of slim-profile double glazing when replacing panes in modern windows does not require listed building consent; 

  • the installation of slim-profile double glazing within historic frames is generally deemed acceptable, provided it preserves the special interest of the historic windows. However, consent is still required for double glazing in historic windows; 

  • The replacement of windows, that do not contribute to a building's architectural or historic interest, with sympathetically designed double-glazed windows is generally acceptable, albeit still necessitating listed building consent  

Exceptions in which installation is unlikely to be acceptable may include historic windows with significant glass, frames unable to support slim-profile double glazing, or windows with leaded lights. 

It is important to remember that original or historic window frames which contribute to the special interest of a building should not be replaced unless it can be clearly demonstrated that repair is not feasible. 

Installation of Electric Vehicle Charging Points 

Additionally, the draft HEAN addresses explicitly the installation of electric vehicle charging (EVC) points in both non-listed and listed buildings within Conservation areas. For non-listed buildings, EVC installation is considered permitted development. However, for listed buildings, EVC attachment to the building will likely necessitate listed building consent. Despite this requirement, EVC installations are generally deemed acceptable, subject to certain conditions, such as visibility and aesthetics.  

Solar Panels and Heat Pumps 

Furthermore, the note elaborates on the installation of solar panels and heat pumps in listed buildings. While these sustainable features can be integrated into listed buildings, careful consideration must be given to their placement to ensure they are sympathetically sited and do not compromise the historic fabric of the structure. 

Listed building consent is always required for the installation of photovoltaic and solar thermal panels, but the draft HEAN clarifies that they aregenerally acceptable on non-principal roofs. Similarly, the installation of heat pumps is feasible, albeit requiring listed building consent. Additionally, loft insulation (provided it is not sprayed) and insulation placed under or between floors are generally considered acceptable measures to improve energy efficiency in historic buildings. 

Public Consultation Responses  

The draft HEAN has elicited responses from various stakeholders, including the Institute of Historic Building Conservation (IHBC). While supportive of well-considered adaptations, IHBC has voiced concerns regarding the draft's shortcomings, citing inaccuracies, omissions, and inconsistencies with the National Planning Policy Framework (NPPF): 

"The draft HEAN is simplistic and makes superficial generalised statements regarding the acceptability of specific adaptations.  … The IHBC is particularly concerned that the draft document makes statements about the need for listed building consent which are inaccurate and that certain adaptations are ‘generally acceptable’,notwithstanding the need to balance any harm to heritage significance against public benefit set out in the NPPF."

In January 2024, the Government (DLUHC; DCMS; DESNZ) published guidance titled 'Adapting historic homes for energy efficiency: a review of the barriers’, published in January 2024, acknowledging the significance of the HEAN in addressing obstacles to energy-efficient adaptations in historic homes. The Guidancealso identifies key challenges and proposes solutions to facilitate sustainable adaptations in historic buildings. 

It addresses barriers such as planning permissions, local authority skills and capacity, lack of guidance, lack of skilled professionals and affordability. Proposed solutions include streamlining planning processes, enhancing support for local authorities, and providing financial assistance for retrofitting projects. 

  1. Planning Permissions: Addressing confusion, inconsistencies, and delays in planning processes through measures such as Local Listed Building Consent Orders and improved guidance. 

  1. Local Authority Skills and Capacity: Enhancing training and support for local authorities to effectively assess and process retrofitting applications. 

  1. Guidance and Information: Providing comprehensive guidance and information resources to homeowners, professionals, and decision-makers. 

  1. Skilled Professionals: Promoting the development of skilled professionals proficient in retrofitting historic buildings. 

  1. Affordability: Addressing the affordability of retrofitting projects by exploring cost-saving measures, financial incentives, and government support schemes. 

The draft HEAN is currently a key action in delivering Historic England’s Climate Change Strategy, it widely reiterates accepted guidelines and outlines the vital agendaIt is currently pending revision in light of consultation feedback, and, when finalised this will be highly influential to how local planning authorities deal with proposed changes to listed buildings and in conservation areas. 

As discussions continue and stakeholders collaborate to refine guidance and policies, the goal remains clear: to preserve the historic fabric of our built heritage while ensuring its sustainability for future generations. 

Heritage Potential always keeps abreast of all new changes on sustainability updates in order to provide clients with best advice on sustainability.  

For further details on the draft HEAN and government guidance, please refer to the respective publications: