The iconic Palm House at the Royal Botanic Gardens, Kew, is gearing up for a monumental £50 million renovation, set to begin in 2027 and span five years. This ambitious project will involve relocating 1,300 tropical plants, replacing 16,000 glass panes, and restoring hundreds of tonnes of iron to preserve the Victorian masterpiece while achieving net-zero emissions.

A Historic Structure in Need of Renewal

Built in 1848, the Palm House is a marvel of Victorian engineering, designed using shipbuilding techniques to create an unprecedented glass structure housing a tropical rainforest. However, the hot, humid conditions inside have caused significant wear, with rust corroding the iron framework and energy-intensive gas boilers driving high carbon emissions. The last major renovation occurred in the 1980s, making this overhaul critical to ensure the building’s longevity.

The Renovation Plan

The project, for which planning permission has been submitted, will see the Palm House stripped to its bare metal, repaired, and repainted. All 16,000 single-glazed panes will be replaced with advanced insulating glass to improve energy efficiency. Gas boilers will give way to sustainable air and water source heat pumps, aligning with Kew’s goal of making the Palm House net-zero. The adjacent Water Lily House will also undergo a makeover, enhancing the sustainability of both structures.

Challenges of Relocating Plants

Relocating the Palm House’s 1,300 plants is a logistical feat, with some specimens posing unique challenges. The star of the collection, a 250-year-old Encephalartos altensteinii cycad, weighs over a tonne and stands 4 meters tall. “Its size and fragile, slow-growing stem make it the plant I worry about most,” said Thomas Pickering, head of glasshouses. Scaffolds and supports will be used to move it safely, while other plants are being potted or propagated, and some too large to relocate will be felled. Many have already been transferred to a temporary greenhouse.

Balancing Heritage and Sustainability

“This is a challenging building to make net-zero without compromising its historic aesthetics,” said Rachel Purdon, head of sustainability at Kew. Improved sealing, modern heating systems, and advanced glass will significantly reduce the carbon footprint while preserving the Palm House’s architectural beauty. The current 21°C temperature, vital for the tropical plants, will be maintained more sustainably.

Public Impact and Long-Term Vision

The Palm House and Water Lily House will remain open to visitors for the next two years before closing in 2027 for the five-year renovation. The project’s scale will temporarily disrupt access, but Kew’s team emphasizes its necessity. “We’re ensuring this iconic structure lasts for generations,” Purdon noted. The renovation aims to balance heritage preservation with modern sustainability, securing the Palm House’s future as a global botanical treasure.

A Worthwhile Endeavor

The £50 million transformation of the Palm House represents a bold commitment to conservation, sustainability, and public access. While the five-year closure will test visitors’ patience, the revitalized glasshouse promises to deliver a greener, more resilient home for Kew’s tropical rainforest, safeguarding its legacy for centuries to come.