The Sussex Energy Saving Programme is expected to generate up to £100m of revenue for Carillion.
West Sussex County Council led the procurement for the Sussex Energy Saving Partnership (SESP), which is aiming to deliver energy savings of £30m a year for Sussex residents over 20 years.
Detailed planning will now start with a view to launching the programme early in 2014. It is one of a number of energy-savings initiatives being led by the SESP, working with local authorities across East and West Sussex and Brighton & Hove City Council. The programme aims to deliver energy-saving measures to up to 17,000 households by 2017, potentially rising to 680,000 households over the next 25 years.
Carillion chief executive Richard Howson said: "We are delighted to have been selected as the delivery partner for this important programme of energy-saving refurbishments in Sussex. We look forward to using our sector-leading expertise, delivery capability and sustainability credentials to support the council's strategic plan for economic and social regeneration, for a low-carbon economy and for tackling fuel poverty."
West Sussex County Council leader Louise Goldsmith said: "Carillion has shown commitment to Sussex and the local economy, in-depth awareness of our supply chain and customers, openness and flexibility and a real understanding of working in partnership with the council and our many partners."