Harrow on-the-Hill / Sudbury Hill Conservation Area

What this means for your project

• Extensions: Side extensions, and rear extensions of more than one storey, are not permitted development — they need planning permission. Single-storey rear extensions keep their normal limits, but the Larger Home Extension prior-approval route is not available.
• Lofts and roofs: Roof extensions such as dormers are not permitted development. Rooflights are usually fine if they don't project more than 15 cm.
• Cladding: Cladding the outside of a house in stone, artificial stone, pebble dash, render, timber, plastic or tiles needs planning permission.
• Outbuildings: Garden rooms, sheds and other outbuildings to the side of the house need planning permission.
• Demolition: Demolishing a building larger than 115 m³ needs planning permission. Taking down a wall, gate or fence over 1 m high next to a road (or 2 m elsewhere) also needs permission.
• Trees: You must give the council six weeks' notice before cutting down or pruning most trees (trunk over 7.5 cm across at 1.5 m high), even if they are not protected by a tree preservation order.
• Article 4 directions: Councils can remove more permitted development rights — for example for windows, doors, porches or front boundaries — with an Article 4 direction. Check the council's list below.