More than 2,195m³ of engineered timber has been used in a pioneering leisure centre in Staines-upon-Thames, designed to meet Passivhaus standards.
B&K Hybrid Solutions played a key role in delivering the UK’s largest Passivhaus leisure centre, supplying 127m³ of glulam alongside 2,067m³ of Stora Enso Cross Laminated Timber (CLT).
The brief for Eclipse Leisure Centre was to create the UK’s largest 50/50 wet and dry facility built to Passivhaus standards, all while staying within tight budget and sustainability targets. The building also needed to use 60–70% less energy than a typical leisure centre—no small feat for this type of project.
The centre includes an eight-lane 25m main pool and a 20m x 10m learner pool with a movable floor, a six-court sports hall, and 950sqm of fitness space. It also features a standout rooftop with four artificial football pitches, an open-plan café, and a striking staircase that helps create a welcoming, biophilic entrance.
“The hybrid combination of timber and steel, as offsite manufactured products, ensured Eclipse was delivered on time and to budget, setting a new standard for hybrid leisure centres of the future,” Alex Brock at BKHS commented.
“The solution also enabled remarkable performance achievements in both airtightness and energy efficiency. The timber structure sequestered 1,668 tonnes of CO₂e, while a whole-life carbon assessment showed a 12.97% reduction in embodied carbon compared to a composite steel alternative. The building achieves airtightness of 0.4 m³/hr/m² at 50pa and targets operational energy consumption of just 120 kWh/m²/year.”
The design called for innovative engineering to tackle complex structural, acoustic, and moisture challenges, particularly in high-humidity areas like the pool hall.
Although timber was initially chosen for its aesthetic appeal, with large areas left exposed, the design evolved into a hybrid timber-steel solution to make the most of both materials. Timber’s warmth, carbon benefits, and prefabrication advantages were carefully balanced with steel’s structural strength.
BKHS worked alongside GT3 Architects, structural engineer Engenuiti, and main contractor Willmott Dixon. A cost analysis by Willmott Dixon confirmed that a hybrid timber-steel approach could meet the council’s budget without compromising on design or performance.
Using visual-grade timber panels also removed the need for additional finishes, cutting down on material use and reducing long-term maintenance.
