Robert Cantwell was an architect. He later became the Norland estate’s surveyor and designed Royal Crescent. He was also a speculative developer. He became involved with the Ladbroke estate in 1824, when he took over a chunk of building land between Ladbroke Grove and Ladbroke Terrace from Robert Hanson. In 1823 Hanson had entered into an agreement with F W Ladbroke to develop the area and he built Nos. 8-22 even Holland Park Avenue. But for some reason he did not wish to complete the development and Cantwell took over the land and the obligation to build twelve more houses.
The 1823 agreement required Ladbroke to grant 99 year leases of the houses Hanson built. Hanson had the right to take leases personally or require Ladbroke to grant them to his nominees (who might be his financiers or builders who had taken over the commitment on a particular plot). Time on the 99 year leases began running from 1823, so when Cantwell took leases in 1826 of Nos. 1-4 (consecutive) Ladbroke Terrace and No. 38 Holland Park Avenue, he received 97 year leases. He took 92 years leases of Nos. 5 and 6 Ladbroke Terrace in 1833.
Cantwell is assumed to have been the architect of Nos. 2-6 and 24-28 (even) and Nos. 23-27 (odd) Holland Park Avenue, and Nos. 14-32 (even) Ladbroke Grove.