The construction group behind the expansion will carry out the £18 million revamp of a landmark city centre building.
Willmott Dixon will lead the project to renovate the Lewis Building in Bull Street to create 114,000 sq ft of grade A office space.
Two CGIs have also been released showing how the new façade and lobby area will look (above and below).
Owner Legal & General Property announced by rebranding Temple Court as a homage to David Lewis, the philanthropist who founded the eponymous department store chain in Liverpool in the 1850s.
The group's Birmingham branch moved to Bull Street in the 1920s but closed in 1991 when the company went into administration.
Due for completion in summer 2017, the renovation will also provide parking for 74 cars and a 60-space cycle hub with showers and changing facilities.
Floorplates are being remodelled to provide some of the largest in the Colmore Business District at around 17,000 sq ft and a seventh storey will be added, comprising 12,000 sq ft with external terraces and views across the city.
Legal & General Property acquired both the building and
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Senior asset manager Tom Williams said: "With an outstanding track record of renovating historic and listed buildings such as Alexandra Palace, we are exceedingly confident that Wilmott Dixon will deliver our vision for a 21st century workplace in the heart of Birmingham.
"We are taking an under-invested asset and creating a truly landmark location that seamlessly blends a contemporary workplace with the building's historic legacy.
"The Lewis Building represents a fantastic opportunity for Birmingham's commercial market and we have already seen considerable interest from some of the larger requirements currently looking to identify space."
Peter Owen, Willmott Dixon's Midlands managing director, added: "We are hugely proud of our role in creating Birmingham's exciting new future with these projects and are excited to be creating superb grade A offices in the heart of the city's business district.
"This is an ambitious project but will create a significant addition to Birmingham's office market and will represent a fitting legacy to this historically important building."
The refurbishment is being project managed by Ediston Real Estate, while EPR has designed the revamp. CBRE and Bilfinger GVA are joint letting agencies.