To want SD’s room to be multifunctional?

While commendable I don't think it makes sense to downsize your hike just to continue to support her for 6 more months then reassess. If you're not committing to supporting her until SDS is an adult then don't commit and downsize your house creating more issues within the family.

Sounds like you’re going through a lot. You don’t need to be having an argument about a desk in a room. It should be the least of your worries. If SD is only there weekends then don’t even tell her. Use the room Monday- Friday. Buy her a desk/ dressing table that you can use then just move your laptop and bits before she arrives.

It doesn't need to removed though - OP has already said she'll move her laptop out of the room when she's not working, and SD can use it for homework when she needs to.

Put a desk in your bedroom, we have done this as we both wfh ft (we didn't when we bought our house) and all bedrooms are in use, one works from the conservatory and the other in our room. You can buy shut away desks so your desk isn't out when you aren't at work. Alternatively have a shutaway desk created in the livingroom. Your bedroom is the best solution though, no one needs to be in there during the day.

Sorry you are having to deal with all of these circumstances. You are being reasonable.

Could you consider getting a desk on wheels? You could just wheel it in and out of her room and she wouldn't even have to know that you are using the room.

Something like this

https://www.amazon.co.uk/Dripex-Computer-Portable-Adjustable-Keyboard/dp/B09TFCFX22?source=ps-sl-shoppingads-lpcontext&th=1

Why does a 13-year-old need a double bed?

This is going to cause huge problems.

You are completely reasonable. No one should have to work from their own bedroom all day, that’s depressing.

Which of the two other bedrooms would you prefer to work in? Whichever one that is, assign it to your stepdaughter regardless of the bed. Get her involved in choosing paint etc to decorate, make sure it feels like hers. Talk to her like she’s a grown up, and get her involved in problem solving. She must know that you go into her room when she’s not here to clean it, change bedding etc. What could help her feel that she still has privacy in her room if it’s doubling as a study? A lockable cupboard? A bolt on the inside of the door so she can be sure no one is coming in when she’s inside? Curtains around her bed?

You need to make it clear to her that you have to have a proper office area in the new house for work. The only other real option in this house would be to put bunk beds in the bigger room, and tell her she has to share with her little brother when she stays. Which is not something she is going to want to do!

Tell your partner he either gets on board with this plan or you will have to take that £600pcm and spend it renting a working space outside the house or paying for a garden office. You’re a good person to want to continue the maintenance payments at their current level, but you can’t magic up extra money or space that doesn’t exist.

I’ve heard of people using caravans as home offices before. If you have a big enough driveway/front garden at the new house, that could perhaps be an option? It would completely remove you from any noise from inside the house which is a bonus.

OP you sound truly wonderful supporting your own family plus another! It’ll always be the non-step-parent with the loudest voice on here 🙄 put your foot down. You are supporting everyone financially, so they can all disappear and fend for themselves or accept your terms. If you’re working in an area where you’ll be less productive, you risk your job. I have a spare room that I use as an office Monday-Friday and DSD uses at the weekend. Never even considered this was an issue and nor has she as all my stuff is packed up and away before she comes!

Stick up for you!!

If it is literally just walking in with a laptop, putting it on her homework desk then packing it up and removing it at 6pm - how would she even know?

If you are talking about a large piece of furniture with an extra large chair, a desktop PC she can't use, files she mustn't touch etc which would dominate the room then I still don't think YABU but they have much more of an reasonable objection.

I think it means that the person who is currently keeping two households afloat should have their working needs prioritized and protected.

Indeed. But on the basis of what we do know , this seems somewhat pessimistic and premature.

Hopefully the op will confirm that she at least has CI and income protection!

Unfortunately you are all going to have to compromise which means no one will be completely happy.

I think offering the choice of the smaller room to DSD or keeping bed and letting you use the desk during the week is the fairest compromise - keep a box of toys for DS in the living room and your DP makes sure you aren’t disturbed after school.

Alternatively you make sure DP understands just how important it is that your job is keeping everyone afloat so he needs to be on your side re sharing the bigger room.

This screams of someone who's never had to count the pennies.

Bear in mind OP was talking about years into the future and has more information than either of us about what a realistic timeframe for that might look like.

I work from a fold out desk in my own bedroom. Children should have their own space. I'm not sure why you being the breadwinner is relevant. Do you think that means your DH and DSD are less important than you?

OP has said that all she needs is a laptop. She is not planning to turn SD's room into a full home office packed with files and folders. What she is saying is that SDs room will have a desk and OP will be using that desk when SD is not there. What on earth is wrong with that?

A temporary move? That makes even less financial sense to me. Hit by the stress and
moving costs of two house purchases!!

OP… do you have CI cover
and income protection 🤞

Personally I've got CI and feel the same as you about insurance, but evidently either he didn't have it or for whatever reason it hasn't paid out. So they are where they are.

I don't know about years, but doubt most organisations allow years of enhanced pay. DB is senior-ish public sector and I think even that's something like 6 months full and 6 months partial. At minimum there isn't enough information for us to presume he'd be getting enhanced still.

For the future, OP has mentioned a possible move if recovery goes well, so there seems reason to hope it could be a temporary step down. This family really deserve a bit of good luck!

I think its fine. If you want to be able to leave your stuff on a desk then can you look at furniture where there is a desk in a cupboard, at the end if the week you can close it away.
www.dunelm.com/product/olney-hideaway-desk-stone-1000255858?defaultSkuId=31001700&utm_source=google&utm_medium=cpc&utm_campaign=Office_Desks-PMax_%5BGOO-PLA-FURNOFF-DESKS%5D&gclsrc=aw.ds&gad_source=1&gad_campaignid=19823512204&gbraid=0AAAAADGqyX3F-txaqV4BySrl8ZN1Ei7y2&gclid=CjwKCAjw46HPBhAMEiwASZpLRP9kkVCDcr9EmhuVQneDZKUXaBh1DtDMtVhPL4Pd-w0JSRNp0m6noBoCFuMQAvD_BwE

OP, you have my sympathy.
You are a workhorse, supporting and paying for everything.
I think they should be worried about you getting in the car with your child, driving off, and leaving them to it.

Yes, you need to be able to work in a reasonable environment.

Maybe you need to advocate for yourself in an stronger manner, because it reads to me as if your well-being doesn't figure at all.

I don’t think there is a problem with your plan OP, it’s possibly due to how you’re pitching it!

Instead of it being that SD will be sleeping in your office you should reframe it that you’ll simply be using her desk when she’s not there, but that needs to be true. It should be her space when she is at your home without any of your work stuff being in there.

Yes fact he didn’t have CI is… unusual

He is still with this employer on reduced hours. I don’t get the impression this has been going on for years. He’s a father with a young family - is it really so unlikely that he’ll never be able to return full time?

and income protection??

The family’s home depended on his salary and yet he seems to have had zero protections in place

So you are having to economise to support your partner's ex wife who has had a further two children with another man who has cleared off. I am sorry but hell would freeze over before I agreed to this. Yes, her situation is sad if the children have special needs but it is not your responsibility

This. Sorry, OP but it is ridiculous that you are doing this. But it adds even more weight to why you should put your desk where you want. There will nothing left of you in the relationship soon, it will be all about what’s best for your husband’s first family

Critical illness cover I agree, but not the sick leave point. We don't know how long he's been off, only that it's been long enough for him to need supporting through more than one surgery, and enhanced pay pretty much always has a time limit.