TECHNAL has adapted its FY65 aluminium window specification to meet the narrower than normal opening vent dimensions at a best-in-class £52 million student village in Coventry, balancing the requirements for daylighting, ventilation, student safety and aesthetics.
A total of 3,500sqm of TECHNAL FY65 aluminium windows together with the company’s MX52 curtain wall and STII high traffic entrance doors were fitted at the 893-home development. The installation not only contributed to the creation of an uninterrupted, zero combustible façade but also provided a low maintenance solution for the building owner – AXO Student Living.
This is the second Coventry-based student residential project TECHNAL has worked on recently with facade contractor CASU Consulto and main contractor Galliford Try, the first being nearby Godiva Place.
Designed by award-winning practice FBM Architects, Paradise Street is inspired architecturally by the original medieval city of Coventry. The scheme’s homes are arranged in a ‘wall’ and three towers to address the busy ring road, with a gatehouse opening into a 2,000sqm piazza.
Window design balances ventilation and daylighting
To enhance student wellbeing by maximising ‘free air’ ventilation and minimising the use of artificial light, every single window in the development is floor-to-ceiling with each student’s desk located across the window so they can take full advantage of the views of the city.
Balancing the ventilation and necessary daylighting requirements led to the introduction of a fixed and opening vent to each room. This however, presented a whole different design challenge when it came to the window detailing, hailing a true example of design and technical collaboration between the architect, contractor, fabricator, and, of course, TECHNAL to get it just right.
Daniel Holden, Managing Director at Leeds-based facade contractor, CASU Consulto explains: “One of the key challenges we faced with the design specification was how narrow the opening vents had to be to maximise the size of the adjacent fixed light within the aperture. Technal was tasked with ensuring we could achieve an opening vent that was some 53mm narrower than the minimum recommended size, whilst still achieving PAS 24 compliance.”
Initially, TECHNAL and CASU worked together to produce a comprehensive document to demonstrate that the proposed solution met thermal, air and weather tightness. It also confirmed market-leading results in terms of the TECHNAL system’s performance.
Window prototype engineered and tested
Once approved, the team engineered and fabricated a prototype window that proved locking points, gearing, hinges and handles all worked without clashes. ‘Pull-out’ tests were also undertaken to validate the system’s capability.
Eliminating service penetrations through clever ‘veil’ feature
Another design priority was the creation of an uninterrupted facade. Putting it into context, FBM Architects Associate Director, John Senior describes the building’s composition: “At street level, the first three storeys are constructed using a red, handmade facing brick. This represents the social and human element to the city of Coventry and fits in with the traditional aesthetic of the local terraces. In contrast, the 12 to 14-storey aluminium clad towers mirror the city’s industrial and engineering heritage, especially with the development located on the former Merlin Engineering factory where the legendary spitfire aeroplane engines were manufactured.
“To optimise student safety whilst at the same time creating a façade without visually apparent service penetrations, we specified an opaque or non vision veil over the opening window, providing a safe and secure barrier. The window prototype was used to conduct ‘pull-out’ tests to ensure the veils offered a suitable barrier.”
Designed by CASU, the veil detail featured castellated Scandinavian larch cladding fitted to a bespoke mill finished fixing system installed on to the opening window lights. This format spans the first three storeys or townhouses, as they are known, providing a degree of softness and texture at the lower level.
For the windows on the towers, perforated metal screens were fixed over the opening windows enabling access to all services whilst avoiding the display of over 1,000 vents on the building’s facade.
The building design also underwent Computational Fluid Dynamics (CFD) modelling, testing the facade’s wind flow dynamics. As a result, the window reveals are deep-set to break-up the flow of wind across the facade. Likewise, horizontal banding shelves were incorporated for the same functional reason whilst adding to the building’s design.
Excellent thermal and acoustic performance
The windows, which in the tower situations are 1.2m wide x 2.1m high, had to meet a high thermal performance with a U-value of 1.4 W/m2K. Because of the smaller window size, alongside a specially coated double glazed unit that achieved a centre pane U-Value of 1.0W/m2K, CASU and Technal specified thermal foam inserts for the profiles, ensuring compliance with the thermal requirements.”
Acoustically, three different zones were identified across the building, with each zone having its own individual acoustic performance requirements derived from the environmental noise surveys.
Complementing the subtle textures used for the facade’s anodised aluminium panelling as well as the interior colour scheme, the Technal systems are dual colour. Externally they are finished in pearl beige (RAL1033) and white, internally.
Other Technal systems installed include 500sqm of MX52 Visible Grid Curtain Wall. This has been installed into an angled brickwork detail, creating an interesting wedge shape design to the common room spaces.
To the main entrance, Technal high traffic STII doors have been installed and tested to Secured by Design. These feature maglocks and automatic gearing that are tied into the Building Management System, ensuring all doors open in the event of evacuation.
The project overall involved a lot of offsite fabrication. CASU manufactured and delivered weeks in advance to ensure materials were distributed on site effectively. This ensured the job was finished, internally at least, way ahead of the completion of the building fabric.
For more information on Technal systems, please visit www.technal.com/en/uk
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