Home sound insulation..

[Phil]

Hello,
I moved house a few years ago to a 1970s built terrace in a little village. It's a lovely house, with plenty of space. It was perfect.

However, I can hear every single sound from next door.
It's really getting us both down. It feels like a home invasion.

With home working, it's incredibly hard to concentrate.
Further to that, I'm worried that they can hear us.

I want to get the wall insulated and was wondering if anybody else had done similar and if so, how did you do it?

I've seen some kits, but they will take up six inches of the room. That won't work because of where the doors are.

Prior to lockdown, it didn't bother me too much. I was leaving home at 5.00am and getting home at 8.00pm.
My partner had mentioned it, (as she works from home anyway) but I didn't realise the extent of it until I started working from home too.

Any advice or suggestions?