THE former Western Technology School building in Grimsby will be demolished when council staff vacate the premises next April.
North East Lincolnshire Council then plans to put the Cambridge Road site, including the playing field, on the market.
The council has set aside £575,000 for its regeneration partner Balfour Beatty to carry out the demolition, which council bosses say will reduce maintenance costs and make the site more attractive to potential buyers.
The building currently houses council offices, a pupil referral unit and teaching space, but is being vacated as part of the authority's property rationalisation programme.
The Municipal Offices in Grimsby are currently being remodelled to increase the number of workers it can accommodate, in a bid to reduce the number of core office buildings the council occupy from 20 to two.
Staff are due to move back into the Municipal Offices early next year, and the Agile Future project is expected to save the council £1.1 million a year in running costs.
The Western site is also occupied by third party users, including the council's educational improvement partner Serco and the Grimsby Institute.
Serco staff will relocate to the Municipal Offices, while Institute staff based at the site will move into new facilities being developed at its Nuns' Corner campus.
The decision to demolish the building, which has been approved by Cabinet, will result in a loss of £72,000 rental income from the two tenants.
However, a report prepared by council officers states that the level of income was expected to fall as the Institute had already commenced "part withdrawal" from the site and now occupies a smaller area than in previous years.
The report adds: "Should demolition not proceed then estimated on-going revenue costs would be incurred for insurance, security, business rates and boarding up. Business rates costs alone are £70,000." Upon demolition, the council intends to market the entire 25.7-acre site, and seek permission from Sport England for permission to dispose of the playing field, which accounts for 17.3 acres of the site.
The report states that initial discussions with Sport England suggest they would "object to the disposal and loss of any playing field without adequate reprovision."
A spokesman for the Grimsby Institute Group said: "We have always planned for any provision at Space to be transferred to our new state-of-the-art facilities that are under development for the arts, performing arts and music curriculum areas.
"These will be based at our Nuns' Corner campus once our new facilities are completed. NELC's decision to demolish the site will in no way cause disruption to any of our staff or learners."
Have you seen our new website? More news on grimsbytelegraph.co.uk Bookmark grimsbytelegraph.co.uk/news for the best breaking news and exclusive local content. Follow us on Facebook and Twitter