Yesterday we introduced you to the special construction now going on at Queen Richmond Centre West, a new office complex being developed by Allied Properties REIT and designed by &Co. Architects. Today we return for more images of QCR West's uniquely engineered delta frames, where the upper members, those above the node, are now being attached.

Construction of the delta frame, image by StructEngGuy

When faced with the challenge of adding a new 11-storey section over an existing 4-storey, century old building on the site, &Co Architects asked themselves; 'How can we create a new modern project without harming the existing historical building?' The answer: instead of attempting to fuse the old building with the new one, the firm decided to float the new building above the older structure by means of an engineering marvel; the delta frame. 

Construction of the delta frame, image by StructEngGuy

Toronto firm Stephenson Engineering Inc. collaborated with Cast ConneX, also of Toronto, to design the delta frames' cast steel structural components. Three of these frames will support the 11-storey section and create a 70 ft. high atrium in the process. Aside from a reinforced concrete stair and elevator core, the delta frames are the only structures supporting the new office space. Each frame is engineered to support 80 meganewtons (approx. 18 million pounds) of axial compression. Currently uncoated raw cast steel, the frames' legs will eventually be treated with a white intumescent fire protective coating called FIREFILM by A/D Fire Protection Systems that expands when heated, creating a thermal barrier to protect the structure. 

Rendering of the intumescent fire protective coating legs, image courtesy of Allied REIT

Construction of the delta frame, image by StructEngGuy

QRC West, due for completion in mid-2015, will undoubtedly become a landmark in Toronto’s Entertainment District. By using the delta frames to float the new modern structure, each component of the development is highlighted and will be seen as a building of its own accord. When people think of QRC West, they will envisage the new engineering feat-cum-architectural form which preserves the century old masonry building while allowing for the city's growth. A similar solution employed at OCAD University in Will Alsop's Sharp Centre for Design is now an icon of Toronto. 

Rendering of the new building floating above the old structure by means of the delta frame, image courtesy of &Co. Architects

North-South section looking west, image courtesy of Allied REIT

We will return to bring more up-to-date shots of the work as it progresses over the coming days and weeks. For more insight on QRC West now, visit our dataBase file, linked below. Want to get in on the discussion? Choose the associated Forum thread link, or add your voice in the comments section on this page.