Kew Gardens' Palm House is getting a £50 million climate-friendly makeover: Iconic Victorian glasshouse will SHUT for four years in major net zero push

It's one of the most iconic glass buildings in London.

Now, experts have confirmed that Kew Gardens' Palm House is getting a £50 million climate-friendly makeover. 

The Grade I listed Palm House, a 362ft long structure at Kew Gardens, is the world's oldest surviving Victorian glasshouse, dating back to 1848. 

Last renovated in the 1980s, the stunning Victorian structure, which takes the shape of an upside down boat, houses palms and other tropical plants. 

But it is 'showing serious signs of deterioration' and easily leaks heat, which increases energy consumption and contributes to the climate crisis. 

The £50 million renovation will replace an antiquated Victorian heating system, fit new glass panes, repaint the white iron frames and redesign the interior for visitors. 

Palm House's hard-to-find exotic species – numbering more than 1,000 – are threatened if the building is not better designed to retain heat and humidity.  

'At the heart of this project is the need to protect the extraordinary plant collections,' said Tom Pickering, head of glasshouse collections for Royal Botanic Gardens at Kew.

'Besides being beautiful, many have cultural, scientific and conservation value, and replacing these collections is unimaginable.' 

On Wednesday, Kew submitted a planning application to the London Borough of Richmond upon Thames to undertake the 'landmark' renovation, as well as the nearby Waterlily House. 

The start date of the renovation will depend on planning permission, but it will begin in 2027 and take at least four years, subject to funding. 

For now, Palm House and the surrounding space is still open to the public. 

It was back in 1844 that work began on Palm House, designed by Decimus Burton and constructed like the upturned hull of a boat by Irish boatbuilder Richard Turner. 

By 1848 it was completed and it remains the heart of Kew Gardens, but today it is 'showing serious signs of deterioration' and is 'not energy efficient'.

As part of the renovation, the structure's aged Victorian gas-fired boilers are to be replaced with fully electrified heat pumps to halve energy consumption. 

This more sustainable solution reduces the carbon footprint of the glasshouse whilst regulating internal temperatures to 64°F-71°F (18°C-22°C). 

Each one of the 16,000 glass panes will be recycled and replaced with new ones, lined with modern sealants to better retain heat and humidity. 

Currently, much of the heat generated by the boilers is lost through the glass, which results in wasted energy – much like an open window above a radiator.

Kew Gardens is hoping to be 'net zero', which means it will be reducing consumption of energy generated by fossil fuels – linked to the ongoing climate crisis. 

Meanwhile, the rapidly-peeling wrought-iron frames that make up the skeleton of the structure will be stripped and repainted in their iconic white. 

An updated Palm House will also have rainwater storage mechanisms and fabric fittings to increase thermal insulation, while remaining 'sensitive' to the original materials and finishes done by the Victorians. 

When it reopens, visitors will benefit from a 'circular welcome space' for groups to gather, refurbished steps and doors and new handrails to improve accessibility – making the space 'fully inclusive'. 

During the renovation, the vast greenhouse will have to be empty, so more than 1,000 plant species will have relocated and stored in similarly heated conditions. 

According to Kew Gardens, Palm House contains tropical plants that originate from some of the most threatened environments in the world. 

Among its treasures are the oldest pot plant in the world (Encephalartos altensteinii) which arrived at Kew in 1775 and is native to South Africa, and the disease-fighting Madagascar periwinkle, valued for medicinal properties.

There's also the Madagascan palm, also known as suicide palm, which lives for about 50 years, flowers once, and dies soon after. 

The relocation and propagation (new plants grown from seeds and cuttings) of the specimens by Kew’s expert horticulturists has already begun. 

But Kew Gardens stressed that it is still seeking funding for this ambitious project – and is taking donations from the public through its website. 

Without 'urgent' funding, Palm House and Waterlily House, and the vital tropical plant species in them, are 'at risk of being lost forever', it says. 

Richard Deverell, director of Royal Botanic Gardens at Kew, called it a 'pivotal moment' in the history of the gardens, which were founded in 1759. 

'With sustainability at the core of our mission, this project exemplifies our commitment to safeguarding both the environment and cultural heritage,' he said. 

'The transformation of the Palm House and Waterlily House into net zero icons will not only protect irreplaceable plants but serve as a beacon of what sustainable heritage can achieve.'

Palm House reflects a Victorian love of glass buildings, which maximised light but were incredibly expensive to build, making them a status symbol of wealth. 

The 1,851ft-long Crystal Palace, completed three years after Palm House, boasted the greatest area of glass ever seen in a building. 

Designed by renowned English architect Sir Joseph Paxton, the Crystal Palace was built in Hyde Park at a cost of £80,000 (nearly £10 million in today's money). 

It hosted the Great Exhibition of 1851 – a vast event showcasing sculptures, machinery, diamonds, telescopes and much more from around the world. 

Afterwards, Crystal Palace was relocated to Penge Common, near Sydenham Hill in south London, where it remained until sadly destroyed by fire in November 1936.