Heritage Category:
Listed Building
List Entry Number:
Date first listed:
Date of most recent amendment:
Statutory Address:


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Statutory Address:

The building or site itself may lie within the boundary of more than one authority.

Greater London Authority
Hillingdon (London Borough)
National Grid Reference:
TQ 09984 87248


TQ 0087 Ruislip 804/12/10057 Former Air Raid Precautions Building, Windmill Hall

- II

Gas de-contamination centre, later church hall. Built in 1941 by Ruislip and Northwood UDC to counter the expected gas warfare on civilians. The style is derived from Dudok. Built of reinforced concrete clad in wirecut bricks in English bond with metal-framed casements and flat roof. L-shaped on plan. Mainly one storey but two storey tower to west. North front has 4 narrow single metal-framed casements and triple casement to right with projecting brick stringcourse underneath. Brickwork around the windows shows signs of fixing for external shutters. Flush door with rectangular fanlight with frosted glass and later low disabled access ramp. Projecting two storey west tower ( boiler room and water tank ) has tall window on north face with flat semi-circular shaped concrete lintel above. East side has two casements at the top and west side has one window at the top. Corner chimney projects and has three recessed channels. Separate access to tower on south side. East and west sides have 5 triple metal casements and brick projecting stringcourse below windows. South end has two separate entrances. INTERIOR: North part has toilets on either side of door, small room on east side, larger room to west with triangular shelf and double wall opposite probably acting as an airlock with two cupboards with shelves for clothing. There is a long room with three concrete roof girders which leads into two separately accessed rooms at the south end each with outside access. The long room probably had partitions originally. Wooden parquet floor probably added later. Layout of the gas de-contamination centre would have included an undressing area, eye douche and showers, drying rooms and dressing rooms.

["Twentieth Century Defences in Britain" CBA p75 explains a typical arrangement. ]


The contents of this record have been generated from a legacy data system.

Legacy System number:
Legacy System:


Books and journals
Twentieth Century defences in Britain, (1995), 75


This building is listed under the Planning (Listed Buildings and Conservation Areas) Act 1990 as amended for its special architectural or historic interest.

End of official listing

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Date: 16 Sep 2007
Reference: IOE01/16790/06
Rights: Copyright IoE Mr Steve Kirkland. Source Historic England Archive
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