Victorian homes are cooler in summer than modern buildings

Victorian-era homes, numbering over four million in the UK, were built before sophisticated computer modeling was used in architectural design. Despite their age, these homes frequently maintain cooler internal temperatures during summer compared to many more recently constructed buildings. This difference is attributed to several fundamental architectural elements.

Many Victorian homes incorporated external wooden shutters, an effective method for blocking solar heat before it could penetrate the building. While modern UK homes rarely feature external shutters, partly due to the incompatibility with outward-opening casement windows, these shutters were common in Southern and Central Europe where summers are historically hotter. As the UK's climate changes, some regions are projected to experience Mediterranean-like summers by mid-century.

Internal shutters were also a feature of Victorian homes. Though less effective than external ones as heat has already entered the building, they still offer more protection than an unshaded window, especially if painted a light color to reflect heat. Their primary benefit, however, was heat retention during winter. Many internal shutters survive today, less susceptible to weather damage or removal during window upgrades.

Striped canopies and awnings, reminiscent of Victorian high streets, also played a role in blocking the sun's heat before it entered buildings. These were compatible with outward-opening windows, allowing for ventilation without obstruction, and provided shaded areas. While less common now, many Victorian buildings featured them, and their reintroduction is considered feasible, with awning boxes often still integrated into building facades.

Ventilation was another key factor. Victorian homes utilized sliding sash windows, which allowed for simultaneous airflow in and out, even with shutters closed. The separate upper and lower operable sections of sash windows enabled hot air to escape at the top while cooler air entered at the bottom. Furthermore, the design for open fires in winter required significant outdoor air intake and multiple chimneys for smoke removal, leading to less airtight homes. This inherent "leakiness" allows cooler outside air to enter during summer, and suspended timber floors could store cool air beneath the building, providing a cooling effect. Modern homes, with central heating and a focus on airtightness for energy efficiency, lack these natural cooling mechanisms.