Kew Gardens has announced a major restoration project for its two iconic Victorian-era glasshouses, the Palm House and the Waterlily House, aiming to bring them into the modern age with net-zero carbon operations. The project will be led by Hugh Broughton Architects in collaboration with Kew’s Capital Projects Team, with work expected to begin in 2027 and continue for four to five years.

The renovation will mark a historic shift in how the structures are heated. Originally warmed by coal, oil, and gas, the new system will rely entirely on electricity, supported by air- and water-source heat pumps. The overhaul is part of Kew’s broader Climate Positive 2030 strategy and will be the first time that renewable energy has been used to power the landmark buildings.

Designed by Decimus Burton and constructed by ironmaster Richard Turner in the mid-19th century, both glasshouses are renowned feats of Victorian engineering. The Palm House, completed between 1844 and 1848, is the oldest surviving structure of its kind in the world, while the Waterlily House dates to 1852. However, the buildings’ ornate iron frames have suffered from decades of exposure to humidity and high temperatures necessary for maintaining plant life, requiring substantial maintenance every few decades.

“The Palm House and Waterlily House are instantly recognisable icons of Victorian innovation,” said architect Hugh Broughton, whose firm is overseeing the restoration. “Their designs were groundbreaking, but after years of serving as vital environments for botanical collections, they now need careful and modern renovation.”

One of the most significant updates will be the replacement of 16,500 glass panes, which were installed during a previous refurbishment in the 1980s. The new glazing will feature custom clear silicone gaskets to minimise heat loss, and original ventilation systems will be reinstated to improve airflow. Rainwater storage and irrigation systems will also be upgraded.

Inside the Palm House, a new central gathering space and additional seating in the northern and southern apses will be introduced, enhancing the visitor experience. At Waterlily House, the focus will be on improving accessibility and visitor flow. The original ornamental garden by landscape architect William Nesfield, located outside the Palm House, will be carefully restored as part of the landscaping improvements.

“This exciting project will help to conserve and decarbonise these inspiring glasshouses and make them more accessible to a wider audience,” Broughton said. “It will elegantly reflect Kew’s ambitious sustainability goals and serve as a reminder of the fragility of the world’s rainforests.”

Specialist collaborators on the project include Martin Ashley Architects (historic buildings), Ramboll (structural engineering), Cundall (services engineering), and Firmingers (quantity surveying). Kew Gardens has already begun the complex process of relocating the 1,300 plant species currently housed within the structures, with large or delicate specimens being propagated instead of moved.

Once completed, the glasshouses will not only represent a landmark in Victorian restoration but will also stand as a model for sustainable heritage conservation in the 21st century.