Dragons returning to London after 230 years

Colors

Simultaneously, the team worked on the color for the dragons, collaborating with a specialist in old painting techniques to devise a color scheme to match the descriptions of the fabled beasts, which are said to have been "iridescent".

Selecting the right material for the dragons on the upper section of the building proved time-consuming. "We started off with timber and soon realized that it was too heavy for the building," Hatto said. The team then looked into selective laser-sintering material, a type of durable and lightweight 3-D printing material used in the construction of Formula One cars.

The restoration team collaborated with a number of universities to test the material to see if it would last on the building, according to Hatto. "We undertook a whole raft of research, from testing paints, materials, weight and wind loading. It has also been tested for weather resistance in wind tunnels at Kingston University. All the information that came back suggested that this material was the correct one for the building. Hopefully this will mean our dragons will survive longer than the last ones did," he said.

Eight dragons on the lower section, which are about 2.3 meters high, were carved from African red cedar and painted in the style of the 1700s. None of the remaining 72, rising to the 10th floor and created from SLS material, is longer than 2 meters.

"Using tantalizing contemporary accounts and drawings, and taking inspiration from surviving 18th century dragons in houses and museums, we'll ensure the new dragons are as faithful to the original design as possible," Hatto said.