[1] In 1927 the council moved to a converted house called Southfields at 265 High Street, which served as both its offices and meeting place.

In 1929 it was enlarged by gaining from Uxbridge Rural District the parishes of Cowley, Harefield, Hillingdon East and Ickenham.

Supporters: On the dexter side an heraldic tiger or and on the sinister side a Pegasus argent hoofed and crined azure both gorged with an astral crown vert and pendent therefrom a plate fimbriated also vert the dexter plate charged with a garb proper and the sinister with a cross throughout gules.

[7] The pile is from the arms of the ancient Basset family and the heraldic fountains refer to the district's rivers.

The national lion holds a seax (Saxon sword) from the arms of the County Council of Middlesex.