Definitely annoying. How did you come to be basically neighbours? Did you move close to him or him to you?

How does he get into your house?

Why not lock the door? Don't answer your phone when he rings.

I agree with PP. If you're busy lock your door and ignore.

You need to set a clear boundary that between 9 and 5 (or whenever) you are not to be disturbed unless it's an emergency, and you need to actually follow through on it. You don't intend to but you're sending mixed messages by saying you're busy but then going around with icing sugar!

I totally get it, my dad (who passed away last year) became very clingy after my mum died. When we were kids he was a hyper workaholic and was almost never at home. I have a pretty demanding job and he seemed incapable of grasping that it was the same for me.

He used to call several times a day (thankfully we didn’t live in the same town) with pretty trivial questions: everything from talking about plans for Xmas in September to asking for advice about how to cook something. I was sympathetic to a point but also feel there was a large helping of misogyny involved, because he used to lean heavily on my mum for all things domestic he felt he could simply transfer all of that dependency to me as her eldest daughter and it was a bit cheeky.

I did eventually start laying boundaries down because it was impacting on my ability to work. You should do the same. Your dad shouldn’t be plonking himself down in front of the tv if you’re working.

I live a long way away for this reason. I need my own life and space.

Pull the blinds down in your office and don't answer the door.

When you’re working, you’re at work and therefore not available. You absolutely need to lay down boundaries very firmly, because he’ll get worse as he gets older.
Why doesn’t he stay in his own home with his wife? Why does he ask you for icing sugar instead of buying some or asking his wife to?
You’re right in that he sees you as a PA/carer/entertainment and you’re letting him do it. You’re letting him put the TV on when you’re working - I would never allow that. Your home is your place of work during working hours.
Yes he might sulk about your house rules but that’s a price worth paying. Just ignore the tantrums. He’s treating your home as his own and you as his assistant. That’s bad enough even when it doesn’t impact your work.

You need to start practising a rebuff at the doorstep - he can’t come in, you’re working. Not a foot inside. ‘Thanks, Dad - I’ve got to go now though because I’m working’ and shut the door. Keep doing it. That’s the negative bit.

Then you also need to do some positive reinforcement training too - invite him over for a specific time each week/weekend, a meal or coffee etc. Pop round to his house. Call regularly at X time.

I'd switch up your routine a bit, can you tell him you're working from the office a few days a week? Catching the bus, so the car would still be on the drive? I think you need to stop being there and available. Open the door with your coat on and say you're just on your way out but you will ring him later. Work upstairs for a few weeks and don't open the door. Say you're in meetings, etc

Also is there any way you can check with his DW if she's noticed any other changes in behaviour, if this is a new thing? He could be beginning with some dementia, which can creep in with just general "oddness" at first.

Arghh, how irritating.. I can feel my heart beating faster just at the thought of it.. I think I would be inclined to give times when he CAN come over, & say you won't be answering the door if it's outside those times, as this is your LIVELIHOOD and you need to work.. then if he sulks, he sulks..

As other posters have said, I'm wondering about the wife too.. she sounds very quiet or absent in all this?

I don't see the problem with letting him sulk really. If nothing else it will give you a few days peace.

And when he stops sulking just be bright and breezy, don't acknowledge it, just like a fractious toddler.

Reiterate the times you are busy and then just let him get on with it. His sulking is his problem not yours. I agree with making set times for visits, although vary the days and times as you don't want it to become a 'every Tuesday between 1-2' scenario.

Apart from anything, if I was your boss I wouldn't be that thrilled that you were having visitors coming round and chatting or sticking the telly on while you were meant to be working.

You clearly need to be a lot firmer. 'Dad, I am working. You can't come round for a chat or watch telly while I'm working. You wouldn't be able to do that if I was in the office and you can't do it while I'm at home either. I can't chat while I'm working and I can't have the TV on. It's unprofessional for someone to have visitors while they're working from home and if you come round again, I won't let you in.'

I know he will just be so childish and sulk if I lay the law down

So what? Sounds like a bit of silent treatment from him would be bliss.

You need to be firmer with him. Don’t let him in when working. So what if he sulks and doesn’t speak to you for a few days? Perhaps you will get a break from it as a result!

Stop letting him in the house when you're working!

You need to have a chat with him about not coming round while you're working. Use a white lie like your boss has complained about hearing people/tv in the background or productivity reducing and you don't want to get disciplined, or taking on a new project that involves a lot more meetings or tel calls.

Pull down blinds in office or get window film that stops people seeing in
Phone on silent or dnd if he calls
Lock back gate

If he complains just refer back to the conversation "dad I told you this last week I'm in meetings all the time and it's on video so I can't get up and answer the door. It's never for anything important, you can watch TV in your own house."

If you don't want him coming round in the evenings invent a new hobby or again just ignore and say you were cleaning with headphones in/gardening out the back.

Basically you need to break the cycle of him deciding he has a right to your company whenever he wants it and your feeling of guilt that you should be spending time with him.

He cba to make the effort for you when you were a child so you have absolutely no obligation now to entertain or help him. You need to get out of the cycle now because it's only going to get much worse when it stops being just company he wants and he starts guilt tripping you with helping him with whatever he can't do as he gets older.

Sorry just seen you don't have a boss but you can still say something like any staff you employ/people you work with have been commenting on someone chatting in the background/ a friend has had an info security issue because a client complained about a family member overhearing private stuff....whatever!

Or just tell him straight "I can't concentrate when you're here and there's no reason for you to be. I don't randomly come round to your house and stick the telly on when you're doing something so don't do it to me!"

Oh blimey, so his DW just wants him out of her way when she's not working? Have they no hobbies like normal folk? But whatever, it's not your problem. It sounds like he assumes that you can just take time off work for him whenever you please. Sadly, business doesn't work like that..