Architect designed grade 2 listed Georgian terrace house on a square in london

This article highlights the challenges and opportunities presented by the draft Historic England Advice Note (HEAN) on adapting historic buildings to decarbonise and improve energy efficiency.

As a RIBA Chartered Practice, our commitment to sustainable refurbishment, especially in residential properties, is not just about reducing carbon footprints but about making homes fit for modern living.

Taking a fabric-first approach to sustainable building materials in listed buildings

At Architecture for London, our fabric-first approach to sustainability is grounded in research and an understanding of materials. The embodied energy of these materials and the performance of buildings in use are key considerations in our projects. Our aim is not just to reduce environmental impact but to enhance the quality of life for the occupants through improved air quality and thermal comfort, utilising low VOC and natural materials to foster a healthier indoor environment.

Our work spans both residential and commercial projects, with a significant focus on existing buildings located within conservation areas or listed properties. The unique challenges these sites present require a nuanced approach, balancing heritage conservation with the need for environmental sustainability.

bayswater house interior design with walnut burl desk in study area and Georgian panelled window shutters
Listed building in Bayswater

Bridging the gap: Heritage, planning, and sustainability

The juxtaposition of high retrofit ambitions against the often unsupportive stance of local authorities underscores a critical barrier to meaningful change in the sector. The AECB’s projection that around 28 million homes will require deep retrofitting by 2050, with a significant portion being hard-to-treat homes built before 1930, highlights the scale of the challenge ahead.

Even when retrofitting listed buildings it is essential to adhere to stringent Passivhaus or EnerPHit standards, to achieve the highest possible standard of sustainable refurbishment. If we are to meet the UK’s ambitious carbon reduction targets it is crucial to aim for these Passivhaus standards.

Discover Architecture for London’s listed projects. If you would like to discuss your project please contact us.

HEAN: A critical analysis of sustainable and energy-efficient refurbishments

While the draft HEAN provides some guidance on adapting historic buildings for energy efficiency, it falls short of the progressive stance needed to address the climate emergency effectively. For instance, the advice on thermally efficient glazing mentions double-glazed windows but overlooks the potential of triple-glazed or vacuum-glazing options. These technologies, especially in contexts where traditional options are insufficient, could significantly reduce operational carbon by improving the thermal performance of windows, one of the weakest links in a building’s envelope.

The draft’s stance on insulation and encouraging appropriate, breathable materials is a step in the right direction. Yet, it hesitates to fully endorse external insulation for all elevations in conservation areas, despite its advantages in preventing thermal bridges and reducing the risk of condensation.

Furthermore, while containing valuable suggestions, the draft’s advice to local planning authorities requires a more comprehensive approach. It needs to guide and empower authorities to make informed decisions that favour sustainable heritage conservation. Some councils, such as Kensington and Chelsea, are making more progressive steps, such as allowing solar panels (PV panels) on listed buildings under permitted development.

Georgian Listed building in london with wood fibre insulation for breathability
Listed building wood fibre insulation

An inclusive and proactive framework

Though well-intentioned, the draft HEAN’s recommendations could inadvertently hinder homeowners and professionals in their efforts to upgrade historic buildings. A more detailed and clear structure, better phrasing, and an emphasis on case-by-case considerations are needed to ensure the guidance is accessible and actionable.

Moreover, addressing the missing elements, such as the significance of an airtightness strategy, the importance of breathability in the external building envelope, and the critical role of appropriate ventilation and heating, is essential for a holistic approach to sustainable refurbishment.

A call from architects for radical change

As we reflect on the draft HEAN and its implications for sustainable refurbishment in the heritage sector, it’s clear that a more radical approach is necessary. Encouraging a fabric-first strategy, reducing limitations on Grade II Listed properties, and ensuring local authorities have the tools and flexibility to support sustainable adaptations are steps towards aligning heritage conservation with urgent climate goals.

Architecture for London remains dedicated to sustainable refurbishment whilst also preserving our built heritage. As we navigate the complexities of sustainable refurbishment within the heritage sector, the collaboration between architects, local authorities, and communities will be paramount.

Discover Architecture for London’s listed projects. If you would like to discuss your project please contact us.