IT used to be an imposing structure, housing the buses of the 1930s within its art deco walls.
But for years the former Southdown Bus Depot in Hilsea has been getting increasingly run-down, and it is now an eyesore on the southbound side of London Road.
Work has now started on its demolition by sub-contractors Hughes and Salvidge, on behalf of Mansell Homes.
It will be replaced by 59 flats, with a communal area and space for up to 77 cars.
The development will cost £14m.
The bus depot will be taken down almost brick by brick in order to avoid damaging the Hilsea Lines fortifications to its rear, a car showroom to its north, and the major road which runs in front of the building.
John Waterfield, development manager for First Wessex, which owns the site and has commissioned the building, said: ‘It will be a slow and sensitive demolition – there will be no ball and chain.’
Part of the current building will be used to create the foundations of its replacement, as the concrete and brick will be crushed and used as a base for the T-shaped block of flats.
‘It’s an eco-friendly way of dealing with it, and a cost-effective way as well. It means we don’t have lorries going backwards and forwards to landfill.’
The development is also being built with stringent environmental standards in mind.
It is being built to a standard over and above the usual rules on sustainability.
John said: ‘It’s quite innovative. Running costs for the residents will be as low as we can make them.’
The building work will also be an opportunity for people to learn a new trade.
It was one of Portsmouth City Council’s conditions of granting planning permission for the development that First Wessex create an Employment and Skills Plan, which enables young people, or people who are out of work, to gain work experience.
It is being run in partnership with Mansell Homes, Portsmouth City Council and Highbury College.
The demolition work is due to take around eight weeks, up until the end of August.
Groundworks and drainage and the foundations will be completed by January next year, and the building work is due to be done by the end of 2014 ready for a 2015 opening date.