High-Performance Windows

As regulations tighten and the demand for energy efficiency rises, homeowners actively seek ways to improve their homes. A popular way of increasing insulation and reducing energy consumption is to upgrade to modern, high-performance windows and doors.

Older properties often have traditional sash windows with single panes of glass, providing poor insulation and making them the key area for heat loss. Additionally, traditional timber windows start to degrade over time, needing more and more maintenance to stop them being draughty and cold.

For new builds, developers are actively seeking high-performance windows that not only complement the aesthetic of the home but also meet strict regulatory standards.

Energy Efficiency as Standard

Rose Collection sash windows boast A rated WER ratings as standard. By using the latest technology alongside modern materials and manufacturing methods, they provide outstanding insulation that keeps properties warmer in the winter and cooler in the summer.

Each Rose Collection sash window has a 1.5 W/m2k u-value as standard. Simple optional upgrades to the glazing can reduce that to 1.4 W/m2k.

Trickle Vent In Head

1.2 W/m2K U-value Upgrade

New builds and renovation projects using our Heritage or Ultimate Rose windows can benefit from ThermoVFlex, which reduces U-values to 1.2W/m2k. 

ThermoVFlex uses patented technology developed by REHAU to improve performance via the frame and not the glass. It’s contained within the window profiles, so there’s no visible sign that it’s there. Until ThermoVFlex the only way to get sash windows below 1.4 was to use triple glazing or vacuum sealed units. Both options have significant issues in sash windows – not least of which is the way that they interfere with astragal bars. Both are also very expensive. ThermoVFlex bypasses all of these problems to provide enhanced energy efficiency at a reasonable cost.

Trickle Vent in sash

Effective Ventilation

The changes to Approved Document F (Ventilation) in 2022’s Building Regulations have had a significant impact. Background ventilation requirements increased to 8,000mm2 (4,000mm2 for bathrooms) and—more importantly—were extended to include replacement windows as well as new builds and extensions. 

To accommodate this, we have developed a number of different ways of including trickle ventilation on our sash windows. In particular, our Eclipse and Concealed vent options have been designed to hide the presence of trickle vents from the outside, which is important for sash windows in heritage settings.

Eclipse (Over Frame)
Concealed Overhead
Through Frame
Through Sash

Trickle Vents in Heritage and Conservation Buildings

While the 2022 version of Approved Document F dramatically increases the need for trickle vents, it does provide for certain exemptions. The document references listed buildings, conservation areas and buildings that use “vapour-permeable construction” (such as lime mortar) as examples of buildings that can be exempt.

The exemption needs to be approved, either by Building Control or the Conservation Officer depending on the type of exemption. However, this is a viable way to remove the need for trickle vents on sash windows in older properties, where they don’t suit the style or age of the building. Check our Roseview Guide to Building Regulations for more information.

Overhead Trickle Vent

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