Building magazine waxes lyrical about ISG’s Temperate House restoration

26 January 2018

Building magazine waxes lyrical about ISG’s Temperate House restoration

Replacing 67,000 panes of glass was the tip of the iceberg when it came to the challenges facing ISG at world-leading botanic Kew Gardens in London, UK.

ISG has been restoring the iconic Temperate House glasshouse for the last five years.

As the project nears completion, Building magazine’s extensive five-page feature highlights the ‘formidable set of challenges’ presented by the £34 million renovation of the world’s largest surviving Victorian glasshouse.

ISG’s senior project manager, John Hatton, spoke about the decision to replace each individual pane of glass, making up the Grade I listed building.

“It was the biggest single challenge,” John said.

“Initially, we planned to retain and restore the existing glass, but in the end we decided that removing, cleaning and restoring each pane would be complex, time-consuming and prohibitive.”

ISG’s project team encountered not only structural and logistical complexities in restoring the structure, which is located on a UNESCO world heritage site, but the pressures of preserving some of the world’s most endangered species of plants in the process.

As restoration work took place, the team helped move the vast collection of rare plants, which includes a 250-year-old encephalartos woodii tree, the last of its species on Earth.

220 miles worth of complex scaffolding was then expertly knitted together in a way that fully protected the structure.

“To reach all the glass we had to use internal scaffolding, but as this is a listed building the scaffolding had to be entirely structurally independent and not in any way transfer any loads onto the building fabric,” John said.

“To put it frankly, this was a huge challenge.”

Temperate House is due to re-open to the public in May 2018.

Follow the link to read the full article, Pane management - the restoration of the Temperate House at Kew, which can be found at Please note the article may only be available for registered users.