Decimus Burton became a Commissioner of the new town in 1833. He leased a triangle of land bounded by Mercatoria, St John’s Church, Maze Hill and Kenilworth Road. Here he built The Cottage (now St Leonards Lodge), Maze Hill House (demolished), The Mount (13 houses), The Uplands (6), The Lawn (10), and a school (which became part of the College). Later, in Upper Maze Hill he built Baston Lodge, Tower House and Clone House (now Healey House). He gave some land in Mercatoria for a National School, and completed his father’s seafront terrace by building 72 to 82 Marina.

The popularity of St Leonards was not lost upon the town of Hastings. It had already begun to expand westwards, through Pelham Place and Wellington Square, and further building began. The Eversfield Estate, from whom the Burtons had bought land, saw the potential and it too began to sell off more space, having obtained an Act of Parliament opening the way for speculative builders beyond the Burton boundaries. As a result the area between the two towns began to fill with properties. In 1875 the two towns merged into the County Borough of Hastings, and by then the total seafront had reached some three miles (4.8 km). Soon after that, the Warrior Square and Upper St Leonards areas were being developed.