The St Bedes scheme will see part of a former school demolished to make way for a four-storey, 104-bedroom care home.
Half the property will comprise one- and two-bedroom apartments for rent, the other shared ownership for the over-55s.
Two Victorian villas will also be refurbished to provide offices, a restaurant, hairdressers and cinema.
The St Bedes scheme will be built to the Code for Sustainable Homes, making use of renewable technology and water saving devices, said Mansell.
The contract is due for completion in February 2013.
The Orbit group is eyeing up growth in new build extra care schemes funded through cross-subsidy of shared ownership units.
A boom in demand is expected as councils look to shut down care homes because of the cost in investing in them.
Its first scheme of 18 shared ownership units at Briar Croft in Stratford completed last year and could have been sold four times over such was the demand, said Orbit Heart of England managing director Stewart Fergusson.
Presently, the landlord has several extra care schemes in its 2011-15 funding bid to the Homes and Communities Agency.
Orbit plans to complete 200 units every 18-months to two years with individual schemes aiming to be 100 units or above.