42068
24 April 2025 

Draught-proofing solutions for period homes

Historic England conducted a study on traditional wooden sliding sash windows, whererepairs and draught seals reduced air leakage by 86%, and additional secondary glazing cut it by 96%.

Windows are a significant source of draughts in historic buildings. Draught stripping is a straightforward, highly effective way of reducing air leakage. Traditional solutions, such as brush seals and perimeter seals, can be applied to sash and casement windows without altering their appearance.

However, incorrect application of draught strips can lead to operational issues, such as windows becoming too tight to open or poor adhesion causing premature failure. To maintain functionality and aesthetics, conservation-grade draught seals, such as embedded brush seals or compression seals, should be carefully selected and installed with minimal visual impact.

For those looking to improve thermal performance further, secondary glazing can be a non-intrusive option. A carefully selected product is an excellent solution for listed buildings where double glazing is not an option, as it significantly reduces heat loss while retaining the character of the original windows. Work can be combined with draught proofing, making it more cost-effective and could address up to 50% of total heat loss.

Historic England conducted a study on traditional wooden sliding sash windows, whererepairs and draught seals reduced air leakage by 86%, and additional secondary glazing cut it by 96%.

More advanced glazing solutions include triple glazing and vacuum glazing. Vacuum glazing, in particular, offers the thermal efficiency of triple glazing but with a much slimmer profile, making it possible for retrofitting into historic window frames.

Doors are another common source of unwanted draughts. For external doors, installing perimeter draught seals and a brush or rubber threshold seal can reduce air leakage while maintaining the door's historic appearance. Again incorrect sealing of doors can lead to problems with expansion and contraction in timber, potentially causing warping or operational issues. It is advisable to use flexible materials such as brush seals or discreet rubber seals which will allow the timber to expand and contract through the seasons without limiting the function of the door. Letter box covers and escutcheon covers should also be considered.

Older floorboards often have gaps between them that contribute to heat loss. Applying a flexible filler between the floorboards and, if access allows, insulate beneath the floor with a natural breathable material make a noticeable difference. A common pitfall when sealing floorboards is using rigid fillers that can crack due to natural movement. Instead, linseed oil putty, beeswax-based fillers, marine deck caulking, or specialist breathable sealants should be used to allow slight flexibility without compromising the structure.

Open fireplaces, when not in use, can be a major source of draughts. Chimney balloons or sheep's wool chimney draught excluders are effective, reversible solutions and can be fitted in conjunction with traditional register plates.

Draught proofing in period buildings is a specialist task that requires careful planning and an understanding of traditional construction methods. Retrofitting energy efficiency measures without compromising the building's integrity is challenging and working with an experienced company likeMitchell & Dickinsonis highly recommended.

A contractor with expertise in historic buildings will be able to identify key areas of heat loss quickly. Their knowledge ensures that the most appropriate solutions are applied, balancing modern energy efficiency standards with traditional building materials and techniques. Conservation specialists will also be familiar with the nuances of listed buildings and conservation areas, ensuring that all work is compliant with regulations and does not detract from the historic character of the property.

An experienced team can provide tailored recommendations, from selecting the right type of secondary glazing to advising on underfloor insulation techniques that maintain breathability. With professional input, homeowners and conservation professionals can significantly reduce heat loss while preserving the integrity of the building.

For more information on Mitchell & Dickinson, call 01237 871 127 or visitwww.mitchellanddickinson.co.uk  

-ends-

With compliments:

Taylor Alden
media@tayloralden.co.uk