Restoring the 'Cathedral of Plants'

Located in the Royal Botanic Gardens Kew, a UNESCO World Heritage Site, the Temperate House first opened in 1863 after 40 years of construction. At 4,880 square metres and 19 metres in height, it is the world’s largest surviving Victorian glass structure. But in 2012, it was on Historic England’s At Risk register, MEP was non-compliant, and control of environmental conditions required windows to be manually opened and closed.

Restoration and renewal, minimal impact

In 2012 we produced a Conservation Management Plan which informed the technical and visual approach to the project, which involved conserving the building structure and fabric, including decorative sculpture. The entire mechanical and electrical system was renewed. A new biomass boiler was introduced, achieving a 25% reduction in Kew’s overall carbon footprint, securing the building’s long-term, sustainable future as a horticultural glasshouse. Ventilation principles follow the original design, with high and low-level openable windows, some of which are mechanically actuated and controlled via a central BMS system.

The Royal Botanic Gardens, Kew was the first UNESCO world heritage site to be accredited to ISO14001 standard and all work had to be undertaken with minimal adverse impact on both the local and global environments.

An improved visitor experience

The internal arrangement enables new activities, alongside inclusive access, whilst not impacting the significance of the building. Widened paths within the House provided all visitors with better sight lines, interpretation and reduced congestion. This was created by flooring across the two Octagons which supports multi-functional use.

Horticultural staff facilities and amenities are provided for the public in the South Octagon Basement, accessible from a newly designed circular staircase. Further amenities, including accessible WCs and a small kitchenette to service private functions, have been added to Burton’s plan.