Draughtproofing sash windows in heritage homes

As autumn approaches and temperatures begin to fall, owners of heritage, historic and period properties face a familiar challenge: keeping their homes warm, draught free and energy efficient without compromising the buildings historical character or integrity. At Ventrolla, when it comes to draughtproofing sash windows, our approach is built on over four decades of experience, innovation and a respect for heritage buildings.

Traditional sash windows in period properties were not designed to meet today’s standards and expectations for thermal and energy efficiency. Over time, gaps can form between the sashes and frames, the timber can shrink or warp, and issues with the glazing can arise, all impacting the performance of the window.

The result? Cold draughts, rattling frames, dust ingress and rising energy bills. A single draughty sash window can severely impact a room’s temperature, leading to homeowners having to turn up the heating. Multiply this across several sash windows in a house and you are looking at a problem that drains both comfort levels and finances.

This is where draughtproofing becomes essential, especially for those in listed, heritage or conservation area properties as full replacement often isn’t an option.

At Ventrolla, we are proud to offer various solutions that can honour the integrity of the building while delivering modern comfort. One example is the Ventrolla Perimeter Sealing System (VPSS), which is a tried and tested method for eliminating draughts and rattles from sash windows without altering the appearance.

The process starts with restoring the window to address issues like rotten timber, damaged cords and faulty pulleys. Then, the VPSS is installed in all areas discreetly, including the top of the box, mid rail, bottom rail, parting bead and staff bead. The Ventrolla Perimeter Sealing System (VPSS) draught-proofing technology creates an effective barrier against cold air and draughts entering your property, while preventing heat from escaping.

Typically fitted as standard to all renovated existing windows, as well as all replacement sash and casement windows or doors. The VPSS delivers measurable performance benefits, helping with rattle and draught prevention, protection against water and dust ingress, whilst also providing superior sound proofing – with noise reduction levels of up to 6-10 dB(A) range, offering smoother window operation and improving the Window Energy Rating (WER) by up to 30%. 

Due to its unobtrusiveness and availability in any colour, the VPSS is recognised by planning authorities and conservation officers. It conforms to BS 7386:1997, BS EN 12207:2000 and BS6375-1:2009 Class 3.

An added benefit is the signature patented Sash Removal System (SRS), designed to make ongoing maintenance safer, easier, and less disruptive.

The SRS eliminates frustrations like lost sash cords and the need for scaffolding during routine maintenance, whether for existing or newly crafted windows. Its unique ‘brake’ mechanism secures sash cords firmly in place and allows for effortless removal of upper and lower sashes, providing unrestricted access to the box frame for easy maintenance. It is also discreetly mounted inside the sash, meaning it is hidden internally and externally during normal use.

One of the biggest concerns we hear from owners of listed or heritage properties is whether draughtproofing will impact conservation regulations. The good news is that in most cases, draughtproofing work is a like-for-like repair or maintenance, meaning it does not require listed building consent for the works to be carried out. However, it is important to check with local guidelines and councils, alongside industry experts, before work is completed. We always work closely with conservation teams when necessary, providing detailed specifications and heritage compliant proposals to ensure a smooth process throughout.

Each window is different, and the way they are approached and treated must be viewed individually. Our skilled craftsmen can:

• Draughtproof your existing window with the VPSS system
• Repair and retain the original timber features when extra work is needed
• Replace rotten or damaged sections with custom-made timber replicas
• In the worst-case scenario, our experts can recreate a new timber sash frame as closely as possible to the original

No matter the approach, the result is a window that keeps its original look, while offering a noticeable improvement in feel and performance.

We believe heritage homes should be lived in and loved, not just admired. Draughtproofing is a simple but transformative step that will allow you to continue enjoying the charm of your property way into the future, without sacrificing warmth or efficiency.

Get in touch today to book a free survey with one of our experts and see how we can help.