Eight fire crews are tackling a blaze at Blackdown Hall in Sandy Lane near North Leamington School.
The fire, which is thought to have started on the first floor and has spread through into the roof space, was first reported at 1.43pm this afternoon.
The school is being used by Coventry, Solihull and Warwickshire Resilience as a rest centre for people living at the former Edwardian residence which has been converted to flats.
A cloud of smoke can be seen above the site.
Police have blocked off both ends of Sandy Lane.
More to follow.