Two landmark London heritage buildings have won provincial heritage awards from the Architectural Conservancy of Ontario (ACO).

The London Roundhouse in SoHo and the Chisholm Building on Dundas Street have each been awarded the 2015 Paul Oberman Award for Adaptive Re-Use (Corporate).

Maggie Whalley, president of ACO London, said in a statement, "Both projects demonstrate what imagination, commitment, historic research, and design flair can achieve in the adaptive re-purposing of heritage buildings."

The Roundhouse was built in 1887 as a locomotive repair shop for Michigan Central Railroad, and later became the Sansone Fruit Company for 45 years and then the Great West Steak House restaurant for over thirty years.

Transformed by Nicholson Sheffield Architects and Creative Property Developments, it is now a high-tech office building that houses Ellipsis Digital and Engine SevenFour.

Ellipsis Digital's VP of strategy, Shawn Adamsson, said in a statement, "Our goal from the very beginning was to find a place where our investment and commitment would be a win for our teams, a win for the neighbourhood, and a win for heritage preservation."

Sharon and Hamoody Hassan have painstakingly renewed the historic Chisholm Building for their law offices after purchasing it in 2009.

Built in 1864, it was most recently Grandma Lee's Restaurant before being left vacant for 19 years.

It boasts an Italianate facade and windows, original floors and a Sunlight Soap 'ghost sign' on what was originally an exterior wall.

Originally it also hosted a prominent clock on its facade, which is now in the Museum London collection, and there are plans to replicate it in the future.