£50m Kew Gardens green project to take up to 5 years

Converting a home to reduce its carbon emissions to net zero is a challenge, but it is nothing compared to the task facing experts who are turning a Victorian wonder into an environmentally friendly 21st century building.

An ambitious £50m project has been unveiled to renovate the world-famous Palm House, which sits at the heart of the Royal Botanic Gardens Kew in London and its sister, Waterlily House, to reduce their carbon footprint to net zero by 2030.

The Palm House, which houses a tropical rainforest, and the Waterlily House, account for more than a fifth of Kew Gardens’ carbon emissions. The renovation is due to start in 2027, and when finished, an estimated four or five years later, it will become the first net-zero glasshouse of its kind in the world.

It will involve:

• Removing 16,000 single glazed panes of glass and recycling them. Then new toughened replacements will be fitted and secured with modern sealants to retain the heat and humidity needed for perfect tropical growing conditions. Tests are already under way to find the best type of glass to provide the maximum insulation.
• Cleaning up hundreds of tons of iron which have been damaged over the years by the heat and humidity that help the plants to thrive. The giant wrought iron ribs of the of the structure, which are heavily rusting in places, will be stripped back to the bare metal work, repaired and repainted with a high-tech waterproof paint in the exact shade of white used when the Palm House was first opened to the public in 1848.
• Swapping the ancient gas four boiler system, which was commissioned more than 100 years ago. They will be removed and its piping refurbished and connected to a cascade of air and water source heat pumps, which will more than halve energy consumption. The building uses a huge amount of energy to keep its temperature at 21 °C.
• Repairing the leaky pipework and the vents which open when the thermometer reaches 28 °C.
• Reducing energy use across parts of the 500-acre Kew site by 49 per cent.
• Moving 30,000 tropical plants from the world’s leading collection of rare and endangered species, which will be carefully relocated to temporary glasshouses during the renovation. It includes the world’s oldest potted plant, an Encephalartos altensteinii, a type of cycad from 1775. It’s growing in a pot, and at 250 years old, it’s older than the Palm House itself. It weighs more than a tonne and stands about 4 metres tall, and horticulturists will use scaffolds, supports and braces to protect that precious plant when it is moved.

The Palm House was an engineering marvel of the Victorian age. No one had ever constructed a glass house on that scale before, and the engineers borrowed techniques from the shipping industry to build the huge structure. It was last renovated in the 1980s.

Kew generated £369 million for the UK economy in 2023 and attracts more than 2 million visitors a year, including more than 100,000 school children.

The public will still be able to visit both sites for the next two years before they’re closed for the work. Although the team at Kew acknowledge this will have a temporary impact on visitors coming to the botanic gardens, they assure them that the results will be worth it in the long term.
Architects submitted plans for the work to the London Borough of Richmond upon Thames in the summer.

The project has received funding from central government, the Julia Rausing Trust, the World Monuments Fund and other donors. Kew Gardens has also launched a Palm House Circle for individual donors.

“It is an incredible and exciting project,” said Midlands green energy expert Ron Fox, of Noreus Ltd on the University of Keele Science Innovation Park.

“It shows that no building is too big nor too old to be turned made net zero. I wish the team of architects, botanists, engineers and other experts all the very best; I shall be fascinated to see the end result.”

For those wanting more advice about converting your home to green energy, call Ron on 0845 474 6641 or contact us here.

Caption: Going green in a big way – the Palm House at the Royal Botanic Gardens Kew in London. Picture: Wikipedia