On what grounds can I object to my neighbour's extension?

The strongest residential objections concern amenity: a two-storey element that overshadows your garden, a rear wall that looms over your kitchen window, or new first-floor windows looking straight into your bedroom. Councils assess these against established tests — daylight guidance, the 45-degree rule many authorities use, and privacy distances.

Character and appearance are also material: scale, bulk and materials that jar with the street, or harm to a conservation area or the setting of a listed building. So are practical impacts — parking loss, obstructed visibility at a junction, flood risk, or harm to protected trees.

The list of non-material grounds catches most people out. The council cannot weigh loss of your view, the effect on your house price, competition, construction disruption, boundary disputes, or the fact that you don't get on with the applicant — however real those feel.

Form matters as much as grounds. Objections that cite the specific impact, reference the relevant drawing, and connect it to a policy or standard give the case officer something to act on. Generic anger gives them nothing.

Submit within the 21-day consultation window through the council's planning portal, quoting the application number. And before objecting, check the plans carefully — schemes are often less harmful than the neighbour-letter panic suggests, and sometimes worse.