Sector Operations Building and blast walls at the former RAF Kirton in Lindsey

The Sector Operations Building and blast walls at the former RAF Kirton in Lindsey were designed by J.H. Binge of the Air Ministry around 1940. This building was intended to coordinate and control the interception of enemy aircraft by British and allied fighters.

Constructed from brick and reinforced concrete, the building has a roughly square plan. The exterior features brick laid in either English or Flemish bond, with red brick below the height of the blast wall and buff brick above. It has a flat roof made of thick reinforced concrete, possibly topped with a brick parapet. The main entrances are located on the east and west sides, accessed through angled passages in the blast walls. Each elevation includes Crittall windows with concrete lintels and sills. On the west elevation, there are copper telecommunications or electricity supply points.

Inside, the main space is the operations room, centrally located on a lower level and accessed by two flights of three concrete steps, one of which still has its original handrail. The plotting table would have been situated here, surrounded on two sides by a raised platform defined by a modern balustrade, along with plant and ventilation rooms. The operations room lacks contemporary fixtures and fittings, except for some joinery; it features a modern bar counter and wall art depicting a Spitfire, which are from the late 20th century. To the east, there is a suite of ancillary rooms that likely included a workshop, battery room, and meteorological office. While the internal layout remains, most fixtures and fittings are modern, apart from some doors, contemporary light fittings, and joinery.

Surrounding the building are concrete blast walls on all sides, which have angled openings on the east and west. These blast walls are protected by an outer earth bund.