Is 90mm the future?
Is time running out for 70mm systems? Glass Times editor, Luke Wood, reports on the Zero 90 system from Liniar, a new range that has been designed with Future Homes Standards in mind.
Liniar has unveiled Zero 90, a new, highly energy efficient 90mm system that can achieve U values as low as 0.66W/m2k with triple glazing.
An evolution of the 90mm, Passivhaus certified casement launched by Liniar in 2017, Zero 90 is the result of additional, extensive in-house development and includes options for a casement, rebated casement, mock horn and tilt n turn windows, as well as residential and French doors.
It has been designed specifically for the UK market, with Future Homes Standard regulations in mind, and as a solution for stricter Part L values that will be introduced in 2025. For new build homes these are expected to be as low as 0.8 W/m2k – according to Liniar, most existing 70mm PVC-U systems will not be able to achieve this target.
The new build sector will be a key market for Zero 90 as national housebuilders look for solutions that will comply with future regulations, but Liniar has also developed a version for the retrofit market, called Zero 90R.
This features a rebated frame that can be installed into typical UK window reveals without the need to remove existing plaster work or internal finishes such as tiles. This makes it suitable for the replacement market as well as attractive to local authorities who are responsible for upgrading existing social housing stock.
Liniar adds that it has also worked with hardware specialists to develop suitable hardware to manage the additional weight of triple glazing as well as engineering an innovative trickle vent solution.
The casement and tilt and turn options are also officially certified as Passivhaus components, further extending the Zero 90’s appeal as a next generation PVC-U system.
The new system also delivers excellent noise reduction – Liniar claims it can reduce noise levels by as much as 42 decibels, halving the sound transmission of a standard PVC-U window – and it is also highly sustainable.
Zero 90 is a co-extruded system, which means its core is made of recycled material.
Liniar is currently offering four colour options from stock; white, black/brown, anthracite grey and rosewood, with 34 made to order foiled options also available.
There is currently no option for a flush casement, but Liniar adds that there is the potential to develop one in the future if demand is strong enough.
Liniar’s design and development director, Chris Armes, explained: “By significantly enhancing a building’s energy performance and therefore reducing its carbon footprint, Liniar’s latest window and door system will help developers and homeowners transition towards Net Zero living. Our calculations show that replacing standard double-glazed windows with Zero 90 can save a UK household over £15,000 during the products’ lifespan.
“Not only will Zero 90 lower energy consumption and the costs associated with running heating and cooling systems, it also provides superb sound reduction, ensuring occupants enjoy all the well-being benefits that come with living in a comfortable, quiet home.”
Martin Thurley, Liniar’s group managing director, commented: “As a business we have a commitment to innovate products that will both help create energy efficient buildings and work towards our nation’s Net Zero target. We also have our own target of becoming a Net Zero manufacturer and are well on our journey towards this.
“Our aim is to provide Liniar customers with the means to stay ahead of current legislation, and the Zero 90 system will help them do just that. Even if the proposed Part L amendments are reduced, Liniar fabricators and installers will have the assurance that they can offer something better ahead of their competitors – and that’s what we always strive to achieve.”
Case study
In 2022, Mansfield District Council commissioned four ultra-low energy homes for social housing rental with the aim of achieving Passivhaus accreditation – the first of their kind for the local authority.
As a forward-thinking assembly, Mansfield District Council is said to be proactive in its green agenda, with a target to halve emissions by 2030 and reach Net Zero by 2050.
By engaging a local construction firm to build the new homes on Saundby Avenue, the project was also designed to allow the remote monitoring of energy usage of typical families occupying the two-bedroom homes.
In order to reach Passivhaus status, windows must achieve very low U-Values, with the specified target below 0.8 W/m²K. When Mansfield Council’s quantity surveyor (QS) searched the Passive House database, Liniar was said to be the only company registered for PVC-U windows in the UK.
As an added bonus, the company was located less than 15 miles from the planned construction site.
With Zero 90 windows and doors able to deliver U-Values as low as 0.5 when fitted with quadruple glazing, the system was the ideal choice for Mansfield Council’s test project.
Engaging Liniar
Once the Mansfield QS had discovered Liniar’s product range, he worked closely with Liniar’s design team to establish the exact specification for the windows he needed on the project.
Chris Armes said: “My team and I were very confident the Zero 90 windows specified would ensure the overall performance of the homes reached the Passivhaus standard. Everyone involved in the project was careful to ensure not only that the houses would be the most energy efficient for the tenants, but that the team would also be able to take learnings and apply them to future social housing builds.”
One tenant commented: “My family and I are so happy to be living in our beautiful new home. We’re already seeing such a difference in our energy bills and although the winter hasn’t properly kicked in yet, the few cold evenings we have experienced outside haven’t impacted us at all. Our home is warm and cosy, and we also noticed a big difference during the summer in keeping the house cool.”
Chris concluded: “I couldn’t be prouder that Liniar’s Zero 90 casement windows, along with our French doors, helped the Saundby Avenue homes receive Passivhaus accreditation. Knowing four local families will be living in super low energy homes, especially in the current energy and cost-of-living crisis, is a great feeling.
“High environmental standards must be the future of housing construction, and as such Liniar is well positioned, with a fully recyclable, Passivhaus-capable, superior energy efficient window and door system that also contains recycled material – all manufactured in the UK and helping to reduce the embodied carbon as a result.”
