What would make you object to a neighbour home improvement plans?

[HazelMaker]

Of anything

1. heat pumps where I could hear them
2. windowa overlooking
3. crap architecture
4. intrusive

In general people are entitled to refurb how they like, but I would object if something had a negative effect on my own property and I felt I had a fair chance of stopping it.

I would take a look at your local authority's planning regulations and find what they can and can't do legally before wasting time on it. If it is legal, and that may include aesthetic decisions such as 'crap architecture', you will just be wasting your time.

Tacky tastes.

Not much. Probably just something that would invade our privacy like windows overlooking.

Our neighbours wanted to build a 2-storey rear extension right up to the boundary line. Our bedroom is next to the boundary and so we would have had a brick wall right outside our bedroom window, blocking all the light. We objected, and for a number of reasons, planning permission was refused.

If only we could have objected to them installing a raised patio and hot tub on the same boundary…

If the patio is more than 30cm high it requires planning permission. Depends how long it's been there, but the Council may still be able to take action if it's less than 10 years.

When I lived in a first floor maisonette I objected to the ground floor extending by down digging into the basement. They got planning permission but couldn’t go ahead due to the terms of the lease.

I would object to something that was overbearing and overshadowed or overlooked our house or garden. Or perhaps right up at our boundary
or something that would stand out like a sore thumb/ unsympathetic to existing houses in the street particularly if the street was prominently historic or older houses.
Would also raise objections if it involved felling of a large attractive tree (s).

I think anything blocking your light/views, right upto boundary lines, huge old trees being felled unless they were dangerous.
otherwise I’m pretty much live and let live, who am I to decide that someone else’s taste is “tacky”?

I objected to a detached garage conversion in a house opposite me. My original concern was that the plans made it look like it was being turned into a little self-contained apartment with kitchenette and bathroom and I thought it would be turned into an air B&B or even tried to be sold off as a separate property. The road I lived in was already pretty high-density and super-packed with parking to the point where people often parked fully on pavements so I was concerned that they were potentially making a property that had off-street parking (although didn't use it) into one that HAD to park on the street, while adding extra cars from the new property.
The planning permission was refused for exactly these issues and the neighbours appealed saying actually they wanted the room to run a business (therapy / massage salon thing). They hadn't realised you need permission to run a business in a residential area and so they had to put that application in which got refused because it was a totally inappropriate area to be having that kind of business/customer traffic coming and going.
I don't really think my objection had a huge impact on the actual decision but what I think it did do was mean the planning committee came out and looked at the site in person (I saw them all rock up in a minibus that parked across my drive access 😆) and really look at the site and assess the impact for themselves. So I don't think if a neighbour is being unreasonable and picky it would actually prevent getting planning.