Winner: Civic and cultural interior 2020. MuseumLab is a children's museum in Pittsburgh that has been converted from a lightning-struck library.
The Carnegie library in Pittsburgh had been struck by lightning, leaving it in ruins. The studio drew on the building's former use and the legacy of educational innovation and access has been revived through the museum.
When it first opened in 1890, the library was one of the first free US public libraries. It fell into disrepair and closed in 2006. It now offers experimental art and technology programmes for youth, a charter middle school and space for community events.
Interior alterations from the 1970s were stripped away to reconnect spaces, reintroduce daylight and reveal the bones of the historic architecture.
The resulting "beautiful ruin" has sparked imagination and curiosity, as it challenged the conventions of both preservation and educational settings.
Judges comments: "A wonderfully articulated and resolved design approach, turns a technical and budgetary challenge on its head and succeeds - in surpassing what the project sets out to achieve," said the judges.
"The focus on the end user is evident, as is the collaborative effort - it must have taken."