Neighbour building a 3-storey extension — can I object?

My neighbour has just submitted plans for a 3-storey rear extension that will completely block light to our garden and kitchen. The council is Elmbridge.

The plans show it's 4.2m high and comes right up to the boundary. We only have a small terraced house and this feels massive relative to the street.

Has anyone successfully objected to something like this? What grounds work best — loss of light, overlooking, or something else? Any advice appreciated.

You definitely have grounds for objection. Loss of light is a strong one — check the BRE daylight/sunlight guidance. If it reduces your Vertical Sky Component below 27% (or 0.8 times its former value), that's a solid technical argument.

Also worth checking if it's within 2m of your boundary — if so, height restrictions under permitted development might not apply to their build, but it still affects your amenity.

I objected to a similar extension in Woking last year. We focused on three things:

1. Overshadowing — got a daylight report done (£180) which showed significant loss
2. Overlooking — the new windows directly faced our garden and bedroom
3. Visual impact — the scale was completely out of character with the terraced street

The council sided with us and the applicant had to reduce it to 2 storeys. It took about 10 weeks but was worth it.

Just to add — even if you don't think you'll win, submitting an objection forces the planning officer to address your concerns in their report. If multiple neighbours object, it carries more weight.

Also check if there's a Neighbourhood Plan or any Article 4 directions in your area. Some parts of Elmbridge have extra restrictions.

Thanks everyone — this is really helpful. I'm going to measure the light loss myself first using the BRE calculator, and if it looks bad I'll pay for a proper daylight report.

The overlooking angle is strong too — their new master bedroom window would be about 12m from our garden patio. That feels intrusive.

I'll also speak to the other neighbours. I know at least two others are concerned but haven't done anything yet.

Good plan. One more thing — take photos now from multiple angles (your garden, kitchen, upstairs windows) before anything changes. If it does get approved and you want to claim loss of value later, or if enforcement issues come up, you'll want a record of what it was like before.

Also worth checking the application drawings carefully. Sometimes developers submit one set of plans and build slightly differently. If you spot discrepancies, that's another angle.

This is brillant advice everyone. I had a simlar issue last year with my neighbour building a massive extention. The council was really helpful once we got the daylight report done.

One thing I'd add — don't wait too long to object. There's usually a 21-day consultation period and if you miss it, you're relying on the committee to pick up your concerns, which is much harder.