Heritage & Timber
Modern windows for heritage properties
Gowercroft Joinery Ltd is celebrating 25 years of manufacturing premium quality timber doors and windows .
As one of the fastest growing companies in the window business , Gowercroft has built a formidable reputation for embracing new technologies and developing products that meet the needs of the market in innovative and cost-effective ways .
Its Heritage range , which was developed specifically to solve the problem of replacing windows in old and listed properties , has become a multi award winner and remains one of the company ’ s best-selling product lines .
Replacing old timber windows
Finding appropriate replacements for old single-glazed windows and striking the right balance between performance and aesthetics can be a challenge for the owners of period properties .
When window frames are too rotten to be repaired , the traditional approach from conservation officers has always been to specify like-for-like handmade single-glazed replacements , which usually means having to accept a relatively poor level of thermal and acoustic performance or opt for secondary glazing solutions to compensate .
This approach can be unsatisfactory for those owners wanting to preserve the original aesthetic of their windows and to benefit from modern standards of low maintenance and energy efficiency for a pleasanter and more sustainable living environment .
Energy efficient double-glazing Although high levels of energy efficiency can be achieved through standard factory fitted double-glazing ( typically with a 16 – 20mm Argon filled cavity ), the giveaway ‘ double shadow ’ on the glazing and the chunky profiles required to accommodate heavy double-glazed units are considered to be unsuitable for period properties .
This has led to the popularity of ‘ low sightline ’ slim double-glazing , which aims to combine some of the features of a slim window with better thermal performance . It is achieved by using a heavier inert gas such as Krypton or Xenon to reduce the thermal conductivity sufficiently to create a smaller cavity in between the panes . The sightline is typically reduced to just 5-6mm to allow for thinner window sections .
However , for some time , this type of window has been controversial , not least within the Glass and Glazing Federation ( GGF ) because , in order to achieve such a slim slightline , it has been necessary to reduce the amount of sealant and desiccant used in the perimeter of the unit . This can cause instability and increase the likelihood of unit failure . In fact , there has been much debate as to whether some of these units even comply with the Construction Products Regulations ( CPR ) 1
Vacuum glazing – a giant leap forward
In many ways the ‘ new kid on the block ’, vacuum glazing is completely different to conventional double glazing and a potential game changer in building conservation . Instead of having an inert gas between the panes for insulation , all the air is extracted to form a vacuum cavity between a pane of low emissivity ( low-e ) glass and a pane of clear float glass .
The concept is simple . With no air or gas between the panes , there is nothing to transfer heat , so the thermal efficiency is much greater . The same applies to its acoustic insulation .
For instance , LandVac vacuum glazing has a total thickness of 8.3 mm , ( the vacuum cavity being just 0.3mm ), which is roughly a quarter of the thickness of a conventional double-glazed unit and half the thickness of a typical slimline double-glazed unit .
A revolutionary solution for period windows
Gowercroft is the first window and door manufacturer to have combined vacuum glazing with traditional joinery features to replicate the appearance of a classic single-glazed window but with exceptional energy efficiency .
The first of a new generation of Heritage windows , the Winston Heritage sliding sash was originally developed for the multi-million-pound restoration of Templeton House , a Grade II listed mansion which was once the home of Sir Winston Churchill . This was soon followed by the Richmond Heritage flush casement window .
58 OCTOBER 2023 CLEARVIEW-UK . COM