Defence Infrastructure Organisation Defence Infrastructure Organisation is an operating arm of the Ministry of Defence ( MoD ) , in the United Kingdom , which is responsible for the built and rural estate . The organisation formed on 1 April 2011 after a reorganisation of the Ministry of Defence ' s bodies in charge of infrastructure . It controls 2 , 400 square kilometres , about 1 % of the area of the UK ( 244 , 820 km² ) . As Defence Estates , it was an executive agency of the Ministry of Defence until 2008 . Administration . The agency is managed by its Chief Executive , currently Andrew Manley who succeeded Vice Admiral Sir Timothy Laurence , the husband of HRH The Princess Royal ; other previous chief executives include Sir Ian Andrews , a former Second Permanent Under Secretary , Ministry of Defence . Management of this very large and diverse business relies on a multiplicity of partnerships , not only with industry but also with many Statutory Bodies and NGOs . It also requires an extremely close relationship with those who use the estate - the Armed Forces - to ensure that it meets the requirements to maintain operational capability . It is based on " Kingston Road " in Whitehouse Common , Sutton Coldfield . There are other office sites at Andover in Hampshire , Tilshead near Salisbury in Wiltshire , Wyton in Cambridgeshire and Catterick Garrison in North Yorkshire . Portfolio . The agency ' s property portfolio is diverse and ranges from naval base s and airfields to forces housing and military training grounds . Many of these sites are of national heritage or of archaeological importance . The agency also has responsibility for the overseas estates of the MoD . The majority of forces housing was sold to a private housing group ( Annington Homes ) in 1996 and is leased back . Aims and mission . The agency is responsible for the day to day estates activity through a wide range of maintenance , construction and sustainability issues , with an annual budget of some £1 bn and direct responsibility for over 4 , 000 staff . The agency became a top level budget from 1 April 2005 . The agency ’ s mission is “ to deliver estate solutions to defence needs ” . Its vision , which follows on from this , is to “ provide an estate of the right size and quality , which is managed and developed effectively in line with acknowledged best practice , and which is sensitive to social and environmental considerations ” . As a major client of the construction industry , it is a member of the Construction Clients ' Group . Rationalisation and consolidation . Management of the MoD estate as a corporate asset includes rationalisation and consolidation , working towards focusing the Ministry ' s activities onto fewer , larger sites . Since 1998 / 1999 DE has disposed of land and facilities surplus to requirements to the value of £1 . 46 billion . In devising and implementing an agreed plan with its customers , DIO provides a corporate and long - term view of defence requirements consistent with the Estate Strategy . This will assist in focusing MoD ’ s use of and future investment in its estate , to meet defence requirements for an estate of the optimum size and quality . Organisation . DIO is divided into five operating divisions , supported by the Corporate HQ : Contracting models . The organisation has pursued a prime contracting model with the intent to maximise value for money in defence . For hard FM and construction projects five Regional Prime Contracts have been let ; in Scotland , the South West , South East , Central and East . Soft FM is provided through ten regional Super Multi Activity Contracts , associated with the ten Regional Brigade Areas . The Housing Prime Contract allows for maintenance of the Service Families Accommodation estate . External links . county