News 2018

Deceuninck 2500 aluminium-alternative window ideal for Capital House

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Deceuninck’s 2500 Tilt & Turn window provides a high-performance alternative to aluminium for Capital House, a bespoke student accommodation complex in Southampton.

Opening in September 2018, Capital House is a £20 million refurbishment of an existing 13-storey office building and the development of 11 four-storey student townhouses, providing living spaces for 423 students. Deceuninck fabricator, Dempsey Dyer manufactured and supplied over 1,300 Deceuninck windows for this prestigious development.

The repurposing of Capital House, incorporating ribbon windows and horizontal concrete blocks, led to a complex window specification. On the one hand, low U-Values were required for thermal efficiency, while on the other hand the specification called for low solar gain to prevent the building overheating – increasingly important in a period of climate change. Due to the high-rise nature of the office building design, particular care was needed to calculate wind loading. The project also demanded good ventilation and restricted access for students’ personal safety.

Deceuninck’s 2500 Tilt & Turn window more than met the spec with outstanding performance: U-Value of 1.3 W/m2K, 0.34 G-Value, Class 4 air permeability, Class 8A water tightness, and Class A5 2000Pa exposure. The Tilt & Turn window is ideal for student and high-rise developments as it gives various ventilation options, ensures residents’ personal safety and can be easily cleaned in the side position. Its smooth, contemporary look closely mimics the appearance of aluminium. In Smooth Matt Grey on Grey Substrate, the installed windows look like aluminium inside and out, even when open.

The use of ribbon windows on the 13-storey Capital House building needed special consideration and highlighted both Deceuninck’s and Dempsey Dyer’s technical expertise. These windows run the full perimeter of the building without posts or apertures in between. The two companies worked closely to calculate the wind loading with high levels of accuracy, and use window couplers to ensure safe, secure installation.

Over a two-month period Dempsey Dyer supplied 1,341 windows frames for the project, on time and in full. Capital House will provide luxury accommodation for students in the heart of Southampton.

Call 01249 816 969 for more about Deceuninck’s commercial range and commercial work. You can also download Deceuninck’s full product portfolio from the NBS National BIM Library at