In 1785 Michael Novosielski was granted an underlease of land east of Brompton Road by Morgan Rice and the Reverend Joseph Griffith, who were Smith’s Charity’s immediate lessees of the land. The underlease was for 45 years, the time remaining on their own lease. On the land Novosielski built terraces of housing, including a very grand mansion called Brompton Grange for himself. In 1843 the trustees recovered possession of Brompton Grange when its tenant fell into financial difficulties. The trustees decided to demolish it and use the six acres which the house and its grounds covered to build new houses.
James Bonnin had recently carried out the successful construction of Pelham Crescent and Pelham Place. So, on 25 July 1843 the trustees entered into a new building agreement with him for the development of the Brompton Grange land. Under the agreement the trustees were to grant Bonnin, or his nominees, leases for eighty-four years calculated from mid-summer’s day 1843. The ground rent was to be £250 a year (which is what Braham had been paying for Brompton Grange). But to allow Bonnin time to construct and let the houses the ground rent would start low and would only rise to £250 after five years.
It is believed that Basevi designed Egerton Crescent. None of his drawings for Egerton Crescent survive. But his obituary in The Builder shortly after his death in 1845 stated that “the new part of Brompton Crescent” was designed by Basevi. In 1847 the trustees paid Bonnin £22 to reimburse him for sums he had paid Basevi for drawings. These probably refer to Egerton Crescent
Thirty-four houses were built in what was later to be called Egerton Crescent. There were twenty-four in the crescent itself. At each end, five more houses were built at an angle back from the crescent. Twelve houses of the houses were in occupation by 1845 and all were occupied by 1849.
Novosielski’s original Brompton Crescent faced the new crescent and his houses were numbered 2-25 (consec.) Brompton Crescent. So Bonnin’s houses were numbered 26-59 (consec.) Brompton Crescent. They kept that numbering even after the facing houses were demolished in 1885, and even after the street was renamed Egerton Crescent in 1896. It was named Egerton Crescent after the Honourable Francis Egerton, one of the Smith’s Charity trustees.
James Bonnin was not the direct lessee from the trustees of any of the houses. Twenty-eight of the thirty-four houses in the crescent were leased directly to Stephen Phillips, a timber merchant, who was who Bonnin’s principal financial backer. Phillips then sub-let the houses to James Bonnin senior at ground rents of about £15 a year. This would have been the price Bonnin paid to obtain development finance to construct the houses. Bonnin then mortgaged the sub-leases to get further finance. For instance, he borrowed £2,000 from George Newman, a wine merchant of No. 8 Pelham Crescent, on the security of his sub-lease of Nos. 50-53 Egerton Crescent.