Grimshaw is transforming its adaptable 1970s Herman Miller factory, designed by its founder Nicholas Grimshaw, into the Locksbrook Campus for Bath Spa University.

The heritage listed building on the River Avon in Bath, is being adapted and extended to contain a mix of teaching facilities and social spaces for the Bath School of Art and Bath School of Design.

Due for completion in September, Grimshaw is aiming to "retain and build upon the original buildings' principles of adaptation", in its renovation of the Locksbrook Campus.

"With the original factory design, Nick (Grimshaw) established the idea of the 'indeterminate building', which can adapt to change," explained principal Ben Heath.

"This is a principal that remains part of the practices DNA today – adaptive reuse is a recurring theme within our projects," he told Dezeen.

"Over 40 years later, with the original building transforming to accommodate an entirely new user, it feels like the ultimate proof of concept and also a great model for the future of architecture."

Formerly known as the Action Factory, the Herman Miller Factory is an industrial facility built in 1976 by Grimshaw for the American furniture company Herman Miller.

The building is known for its gridded structure and completely demountable cladding system of fibreglass, louvres and glazing, designed to enable its occupants to freely rearrange the position of window and facade panels.

As part of its overhaul, these iconic wall panels are being be cleaned, restored, insulated and repainted. Inside, the building's existing concrete flooring will also be restored, and finished with clear varnish seal.

More significant changes to the building will include the addition of a rooftop pavilion, which has been designed by Grimshaw to house a third storey of studio spaces.

Inside, the interior layout will be reconfigured so that is largely open-plan, and a first floor mezzanine will be constructed within the building.

The factory will be fitted with a series of fixed workshops that are enveloped by large, open, flexible studios, alongside offices, presentation spaces and meeting places. There will also be a permanent gallery, a cafe and art shop used to promote student and graduate work.

Locksbrook Campus is due for completion this summer, before students begin using the building from September 2019.

"I also hope that it will last another 40 years, continuing to adapt to the changing needs of its users," concluded Heath.

Grimshaw, who gained his reputation during his working 15-year-long partnership with Terry Farrell, established his London-based studio in 1980.

He recently announced he was stepping down as chair of the architecture firm to dedicate his time to a new foundation. The Herman Miller Factory is one of his 10 high-tech career highlights from his five-decade career.