27 March 2026
Across the East Midlands, owners of historic buildings face a growing challenge: how to reduce energy consumption and carbon emissions while preserving the architectural character that makes their properties significant. With approximately 470 heritage sites in the region listed on the Heritage at Risk Register and thousands more in conservation areas, finding the right balance between thermal performance and historical integrity has become one of the most pressing questions in building conservation today. Upgrading windows is often at the heart of this debate, and different European regions have developed their own approaches to encouraging homeowners to invest in better glazing. In Flanders, for example, the regional government offers a Flemish online tool for calculating renovation premiums for high-performance glazing, illustrating how financial incentives can support energy-efficient upgrades in older properties.
The issue is particularly acute in the East Midlands, where the region's built heritage spans everything from medieval parish churches and Tudor manor houses to Georgian townhouses and Victorian terraces. Each building type presents its own set of challenges when it comes to improving energy performance, and the solutions that work for a modern house are often entirely unsuitable for a traditionally constructed building with solid walls and single-glazed timber windows.
The Scale of the Challenge
England has approximately 400,000 listed buildings, and a further 540,000 homes are situated within designated conservation areas. Together, these "heritage homes" account for a meaningful share of the country's domestic carbon emissions. Research has shown that historic buildings contribute around five per cent of total UK emissions, a figure that policymakers and heritage organisations alike recognise must be addressed if the country is to meet its net zero targets by 2050.
Yet the same research also demonstrates that sympathetically retrofitting a Victorian terraced house can result in lower lifetime carbon emissions than constructing an entirely new dwelling to modern standards, once the embodied carbon in building materials is taken into account. Construction of a new home of comparable size produces up to thirteen times more carbon than refurbishment. This finding underlines the environmental case for investing in the existing building stock rather than treating historic buildings as obstacles to progress.
Windows as a Focal Point
Of all the elements of a historic building, windows are often the most contentious when it comes to energy efficiency improvements. Original timber sash windows, for instance, are frequently cited as a major source of heat loss. However, guidance published by heritage bodies suggests that overhauling original windows to ensure a snug fit can reduce air leakage by 33 to 50 per cent without any loss of historic fabric. Where a window is beyond repair, heritage-compatible double-glazed units with slim profiles and traditional glazing bars can offer a sensitive alternative.
The question of how to treat windows in listed buildings has generated considerable debate among conservationists, building owners and local planning authorities. In many cases, the use of uPVC replacements is not supported and will not receive listed building consent, as such materials are considered incompatible with the character of historic buildings. The challenge is to find solutions that deliver genuine thermal improvements while respecting the visual and material qualities that contribute to a building's significance.
European Approaches to Heritage Renovation
The United Kingdom is not alone in grappling with these questions. Across Europe, countries and regions have developed a range of policy instruments to encourage the energy-efficient renovation of older buildings. Belgium's Flemish region, for instance, has introduced the "Mijn VerbouwPremie" system, which combines several renovation and energy grants into a single scheme available for buildings at least fifteen years old. Under this system, homeowners can receive financial support specifically for upgrading glazing to high-performance standards, with the amount of the premium varying according to income category and the nature of the works.
Such schemes offer a useful point of comparison for heritage professionals and policymakers in England, where support for energy efficiency improvements to historic buildings has historically been more fragmented. Understanding how other European regions balance the competing demands of heritage conservation and energy performance can inform future policy development and help to identify approaches that could be adapted for the English context.
A Whole-Building Approach
Heritage bodies and conservation organisations increasingly advocate a "whole-building" approach to retrofit, rather than tackling individual elements such as windows or insulation in isolation. The Sustainable Traditional Buildings Alliance, a collaboration of leading UK organisations associated with the conservation and improvement of traditional buildings, has developed guidance tools that help building owners and professionals assess the interactions between different retrofit measures and their potential impacts on building fabric, energy performance and heritage significance.
This approach recognises that traditional buildings were designed as integrated systems in which walls, windows, floors and roofs work together to manage moisture and ventilation. Intervening in one element without understanding the consequences for the whole building can lead to unintended problems such as condensation, damp and decay. By taking a more holistic view, building owners can identify the combination of measures that will deliver the greatest energy savings while minimising risk to historic fabric.
For the East Midlands, with its diverse stock of historic buildings and its strong tradition of community-led heritage work, the challenge of balancing energy efficiency with conservation is likely to remain a prominent theme in the years ahead. The region's local history societies, heritage trusts and university departments are well placed to contribute to this conversation, bringing together historical knowledge, practical expertise and a deep commitment to the buildings and places that define the character of the East Midlands.