Glazing delivers quiet, comfortable classrooms

The Vacuum Glazing Network (VGN) has completed a high-impact glazing retrofit at St Winifred’s Roman Catholic Primary School in Stockport, demonstrating how modern vacuum insulated glazing (VIG) technology can improve teaching environments, while supporting decarbonisation goals. 

Working in partnership with the Diocese of Salford and the Energy Innovation Agency, The Vacuum Glazing Network (VGN) specified and installed PassivGlas Ultimate units across a south-facing block that had long struggled with excessive heat gain, winter heat loss and playground noise. 

“The building was suffering from solar heat gain, massive heat loss and excessive noise from the children playing in the playground, impacting concentration levels within the classrooms,” says Ian Henderson, Managing Director at VGN. “We were introduced to the Diocese through the Energy Innovation Agency and it was decided, after we provided data, that St Winifred’s would be an ideal pilot scheme.” 

VGN removed the original steel-framed, single-glazed windows and replaced them with thermally broken aluminium curtain walling systems from Premier Aluminium Systems. Around 70 PassivGlas Ultimate units were installed, each designed to combine vacuum insulation with low-emissivity coatings for thermal and solar control. 

“An additional low-emissivity glass lite was added to the insulated glass unit to deal with the problem of solar heat gain,” explains Ian. “With the property elevation facing south, direct sunlight had been overheating the classrooms and making lessons unbearable for both pupils and teachers. They were having to close blinds, taking away all natural daylight.” 

The retrofit also covered glazing to the stairwell and entrance. To minimise disruption, the works were completed across weekends and during half term. Bradbury Consulting managed the project, with Chapelgreen Contracts delivering the installation. 

Comfort, acoustics and efficiency 

The results were immediate. Internal temperatures stabilised and classroom noise levels dropped significantly. The glazing cut sound transmission from 29dB to 36dB – and can reach 41dB when paired with acoustic laminate. 

“It’s the noise they’ve noticed a huge difference with,” shares Ian. “And they get all the sun coming through, without that incredibly intense heat. We are also expecting a minimum of 35% energy savings in the reglazed areas.”  

Headteacher Alicia Duffy confirms the dramatic change, adding: “This block is now fully self-sufficient, as the heat contained by the windows heats the classrooms. Almost all radiators have been removed, and we hope to see a substantial impact on the energy costs for school as a result of the PassivGlas installation. PassivGlas has significantly improved the learning environment for our pupils. Their concentration levels have dramatically improved, and I am certain we will see an improvement in pupil outcomes as a result.” 

High-performance upgrades   

While the school required full replacement frames due to inefficient steel profiles, most education buildings with PVC or aluminium frames can be upgraded with PassivGlas units alone. This simplifies installation, reduces waste and cuts project time from weeks to days, while significantly reducing cost. 

Ian continues: “This project shows how vacuum glazing has moved forward based on modern day buildings and usage requirements. It’s not just for heritage properties. Education, healthcare, social housing are all areas where high-performance glazing can make a massive difference.” 

VGN is now monitoring sensor data from the building, comparing pre- and post-installation readings on temperature, humidity, and noise levels. The school’s energy bills will be reviewed over the next academic year to calculate long-term performance.  

With more than 1,000 buildings in this Diocese estate, and growing interest from universities and housing associations, VGN sees this project as the start of a wider shift in how glazing retrofits are approached. 

“We want to show how existing buildings can be rapidly upgraded with minimal disruption,” says Ian. “PassivGlas offers a practical and cost-effective route to decarbonisation, better learning environments and long-term operational savings – all from a simple reglaze.” 

www.passivglas.com