Movie: Konrad Buhagiar of Architecture Project explains how he built a 60 metre-high outdoor lift in historic Valletta, Malta, in our latest interview with category winners at last month's Inside Festival in Singapore.

Barrakka Lift by local architecture studio Architecture Project, which won the Transport category at the festival, is a 20-storey elevator that takes people from Valletta's historic Grand Harbour to the top of the Maltese capital's sixteenth-century fortified walls.

A lift was originally built on the site in 1905, but was dismantled in the 1980s. "After the Second World War and the advent of air travel, the gateway into the island stopped being the sea," Buhagiar explains. "So the lift was practically obsolete."

"The situation was reversed recently with the introduction of a cruise liner terminal and this brings to the shores of Malta thousands of tourists in one day."

Malta has experienced a number of earthquakes throughout its history, so the lift had to be very structurally strong, Buhagiar says.

This was complicated by the fact that the walls of the city are subject to a conservation order and therefore could not be touched by the structure.

"No structural members connect the lift laterally to the fortification walls," Buhagiar explains. "The lift had to spring up vertically and had to be designed in such a way that it was structurally sound."

'"The staircase, which threads through the centre of the structure, in fact makes the structure much more rigid and therefore seismically strong."

However, Buhagiar says the greater challenge was designing a contemporary structure that didn't look out of place next to the sixteenth-century architecture of Valletta.

"I always say that one can find a solution for the structural and technical problems," he says. "The trouble is, how do you find something that will age well, will not look trendy today and be passé tomorrow, and which will match the timelessness of the manmade landscape that surrounds it?"

"It was important to find a form that had interest today, which looked like it was already old when we built it and would survive in time."

The whole structure of the lift is wrapped in a corrugated aluminium mesh, which was chosen because of how it ages, says Buhagiar.

"Using the mesh helped because it is a shiny, contemporary material but it immediately acquires a patina when it reacts with the saline environment," he explains. "And, because it's very textured, it collects dust. So already when it was built it looked like an old building. At the same time it's contemporary."

He adds: "It's extremely popular. We've been working in Valletta for 20 years and this is the first time nobody - not one person - criticised [the project] because it's a contemporary structure within an ancient setting."

This movie was filmed at Inside Festival 2013, which took place at Marina Bay Sands in Singapore from 2 to 4 October. The next Inside Festival will take place at the same venue from 1 to 3 October 2014. Award entries are open February to June 2014.