Is this subsidence? Photos included. Please help

[BloodyStupidHouse]

I live in an extended 3 bed end terrace. 8 years ago I had my kitchen extended and it was a big job.

All signed off and no issues at all until about a month or so ago, maybe a little longer.

I noticed cracks inside above the door. Looking outside, there are 'stair stepping' cracks in the pointing, again above the door.

My worktop has dropped at one end. My door appears to have dropped - it won't shut properly

There is also what appears to be a distinct dip in my lawn - directly outside the extension on the corner.

My neighbour has some very tall trees in his garden right next to mine. They're well over house height and about 17 feet to the side of the extension. These weren't deemed an issue when the build went ahead

My buildings insurance company said it isn't subsidence and they've got no suggestions for me. They are basing this on a telephone call where they asked me 3 questions

I have had the original builder back out. He is puzzled and doesn't know what it could be - there have been no issues until the past few months

Any suggestions for me please? Do I need a chartered surveyor? Is this really not an insurance issue?

Large, even medium, sized trees don't belong near houses IMO. Or above drains either. Of course, some trees are worse than others, depending on whether they are tap rooted or not. Oddly enough, some shrubs can be worse than some small trees. Our surveyor particularly suggested we removed some rhododendrons that someone had planted along the line of the sewer in our current garden. In fact, just about every tree, though most were smallish, and large shrub here was planted right on top of the drains, despite there being lots of other places that would have been fine for most of them.🙄We had the lot out. Luckily none of them were so large they needed to be done in stages- something to watch out for with larger trees. And our main sewer is actually very deep, which is good....

Hi there. OP- do you have an update? X

Lopping trees too agressively in one go, or taking big ones out all at one go rather than in stages, can create trouble.

Also interested

Don't tell your insurance unless you have a professional opinion.

Otherwise you will be screwed over regardless of if it is subsided

We had a leak in loft tank once. Phoned them but didn't end up claiming as damage was cheaper to repair ourselves.

They then tried to say we were a flood risk dispite being no where near a river and on a hill. How is a loft leak a flood risk and we didn't even make the claim !!!