Prime Minister Malcolm Turnbull and his wife Lucy Turnbull will become the first tenants of the newly renovated official Canberra residence in coming weeks, after the Finance Department quietly announced the heritage restoration and building upgrades had been completed.

Commissioned under the former Labor government, the renovations were originally expected to take just 18 months and cost about $3.19 million. Completion had been expected by April 2014, but work on the Georgian revival-style home was expanded. The final cost is now more than $8.8 million.

A new certificate of occupancy was issued for the home last month.

When in Canberra, Mr Turnbull has been living at his own Kingston Foreshore apartment since toppling Tony Abbott in September.

A spokeswoman for the Department of Prime Minister and Cabinet said most of the furniture and soft furnishings have now been returned to The Lodge and artworks will be installed in the near future.

"The Prime Minister and Mrs Turnbull will move in when these activities are completed," the spokeswoman said.

The exterior of The Lodge after renovations were completed. Source: Department of Finance.

Originally the project included asbestos removal, replacement of the 1980s slate roof, heating and cooling upgrades, new lights and wiring, painting, a new kitchen, bathroom improvements and health and safety upgrades.

The renovations were expanded to include upgraded security systems, improvements to living areas and bathrooms and work on rundown Australian Federal Police guard houses. Other additions included a "luggage lift", soft furnishings and new balustrades.

A spokeswoman said the work brought the home up to relevant building standards. Given "the range of representational and other uses of The Lodge and its historic and heritage status, Finance maintains The Lodge to property management best practice".

The department will continue to manage the property "on behalf of the Commonwealth to maintain the building for the foreseeable future".

Work has been continuing in the property's grounds, including construction of new outside toilet facilities and a new shed for the property's gardeners.

New outdoor toilets built in the grounds of The Lodge. Source: Department of Finance.

Mrs Turnbull has worked with curators from the National Gallery of Australia to choose artworks for inside the home. Artworks owned by the Australiana Fund were removed from the 40-room interior during the renovation.

Designed by Melbourne architects Oakley and Parkes, then prime minister Stanley Melbourne Bruce and his wife Ethel Bruce first moved into the colonial revival-style home in May, 1927.

Originally known as the Prime Minister's Cottage, the heritage-listed home cost more than £28,000 to build. Prime ministers including Ben Chifley and James Scullin all famously disliked The Lodge, while 15 former leaders including Kevin Rudd and Julia Gillard used the residence during their tenures.

A new guardhouse for Australian Federal Police officers. Source: Department of Finance.

Mr Abbott had intended to use the residence but was deposed by Mr Turnbull before the work was completed. He opted to stay in a $110-a-night room at Australian Federal Police College in Barton during his two years in office.

Mr Abbott's office sought to avoid information about the refurbishment being made public, including blocking access to the media. In May 2014, it was revealed a senior bureaucrat said the Prime Minister's office could be concerned about privacy or a poor reaction to the project.

Ms Gillard famously told journalists that possum urine was once seen making its way down the wall of the dining room during the visit of an unnamed world leader.

An earlier version of this story incorrectly stated former prime minister John Howard disliked living at The Lodge. Mr Howard said the house was very comfortable and he appreciated the privilege afforded to his family.