A controversial 1970s building in the historic heart of Cheltenham has been transformed by AWW Architects to provide a contemporary mixed-use commercial development. Neil Smith from AluK reports
Once a 1970s landmark in the centre of Cheltenham, but later becoming an underused and run-down building, the Quadrangle has been completely transformed into a contemporary mixed-use commercial development with aluminium window, door and curtain walling systems.
Designed by AWW Architects from their Bristol studio and completed by Beard Construction, it now features an inner courtyard, ground floor retail space, four storeys of open plan workspace, and the town’s first rooftop restaurant.
The fenestration package was key to retaining the design language of the original building within a more contemporary aesthetic, while also meeting the requirement for improved thermal efficiency, more natural light and better natural ventilation.
The architects specified a comprehensive mix of curtain walling systems at the Quadrangle, including a capless curtain walling system to give a frameless appearance to the retail facade, as well as a more conventional capped curtain walling system for the courtyard area and rooftop restaurant. In addition they specified a system for the entrance doors, and a separate one for the 400+ windows fitted into the existing openings around the facade.
The whole fenestration programme was carried out by fabricator Aluminium Sashes, which used its extensive experience in the repair and replace sector to overcome the challenges inherent in surveying, fabricating and fitting windows into openings. In many cases these were irregular in shape and form, and not aligned with the concrete slab finish.
Some fabricators avoid commercial repair and replace projects like the Quadrangle because of the complexities involved. However when Aluminium Sashes were faced with challenges such as a downstand beam within the structural opening of some windows, creating an awkward head detail, they were able to integrate areas of fritted glass to disguise it.
Getting the details right
The firm worked closely with AluK at the planning and detailed design stage to achieve the contemporary look for the facade that the client and architect wanted. For example, where the original windows had a transom and modesty spandrel panel below, the slimmer sightline replacements replicated the line of the transom but with fritted glass below, to provide a similar level of privacy but with more natural light.
They also designed a solution for fixing the anthracite grey windows to the metallic bronze louvre sections specified to break up the uniformity of the facade, give users the option to open windows, and to provide fresh air and exhaust points for the AHUs. The reinforcing bar in the windows has effectively become the carrier bar for the louvres, and gives the impression that there are two colours in one window panel.
The architect’s view
Dan Basey, project architect commented on the project: “Being able to work so closely with the manufacturer and fabricator at both design and construction stages enabled us to realise this project. The integration of the distinct colour palette and finishes was a key driver of the scheme. The metallic bronze finish works really well with the more neutral anthracite grey, whilst also being sympathetic to the existing colour palette of the Regency-era buildings in the context of Imperial Square.”
He continued: “An integration of both natural and mechanical systems to the rear of the windows’ louvre system is a simple but effective detail that seeks to improve the user-experience of those working in office spaces. This will hopefully become a well utilised feature as more attention is given to improving the air quality of our internal workspaces going forward.”
The fenestration choices were integral to the project’s being awarded a BREEAM Very Good rating, explains Basey: “The recyclable aluminium windows contributed to a BRE Green Guide A materials credit, while the 1.4 W/m2K U-Values reduced the energy demands. The glazed facade with integrated louvres helped achieve both the HEA 01 Views Out and Daylighting and the HEA 02 Indoor air quality ratings.”
Quadrangle is a showcase for our collaborative approach with customers and specifiers. The planning, precision and attention to detail shown at every stage ensured that it delivers on the design intent, yet it has still proved a practical, and cost-effective choice.
Neil Smith is the national sales manager from AluK