The Temperate House, Kew Gardens, London - Cast Iron Ventilation Floor Grilles

Originally opened in 1863 and voted 'Best UK National Treasure' at National Geographic Traveller Magazine Reader Awards, the Grade 1 listed, iconic British landmark, The Temperate House at Kew, reopened in 2018 after a major five-year, £41 million restoration. Comprising five pavilions and showcasing over 10,000 new plants from all over the globe, this glass cathedral is the world’s largest Victorian glasshouse, protecting the often rare and tender plants throughout the UK’s cold winters.

Commissioned in 2017 by renowned architects Donald Insall Associates - heritage and historic building specialists - and working with ISG, the global construction and engineering company, Britannia designed and manufactured 146 bespoke cast iron floor grilles - a total of 73 linear meters - to house part of the vast new sunken trench heating system. The original inadequate and inefficient heating, ventilation, and irrigation systems were no longer in adequate condition or sufficient for the purpose, and a new biomass underfloor heating system was added to produce ambient temperatures for the plants without impacting the integrity of the building.

The finished bare metal design CGA03, meticulously created by our highly experienced pattern makers, echoes the original traditional Victorian grilles found elsewhere within the glasshouse complex and has since become Britannia’s signature grille.

We are exceptionally proud to have been chosen and trusted to complete this award-winning project and are equally proud of our teams to produce it – from design, to manufacture, to installation.

Frequently referred to as Cathedral, Ecclesiastical, or Victorian decorative floor grilles and as seen here, often placed over channels holding heating pipes, they provide a practical and decorative heating vent. Originally designed for churches they are increasingly popular in private houses, greenhouses, and commercial building developments. Our grilles can be ordered in cast iron or cast aluminium and finished in a wide variety of options.

We also work in association with Gunning Heating, making decorative cast iron grilles that fit seamlessly into their underfloor trench heater units.  

See our website for a full list of our grille designs and finishes or contact us to discuss your bespoke requirements.