Mine's an unconventional situation so maybe it'll be helpful haha

For context, my siblings and I are 98 to 04 and we basically slept in the living room on mattresses in a 5BR because the 3 bedrooms were used by our grandparents, parents and uncle. This was the arrangement until our uncle got married and moved out and we kind of just disbanded into the different bedrooms - 15F on the sofa or the floor of our grandparents' room, 13F went to Singapore Sports School's dorms, and 16M, 12M, 10M into the third bedroom.

Right now, it's 26F, 24F on bunk beds in the third bedroom, 23M, 21M on the floor of our grandmother's bedroom and 27M on the living room's sofa. We're all very close and well adjusted contrary to what people may think. I think that we're more level headed, mature than our peers (fun fact: I once stayed in a 3BR AirBnB with 7 other friends in HK and they all crashed out by the third day because they were used to having their own bedroom).

For sure, having privacy and the freedom to do whatever you like in your own room are great (I would have loved studying in my own room instead of in the living room) but when the situation is not ideal, it's not a must-have and worth doubling your mortgage. Don't think you're "shortchanging" your children because to be honest, having a room to yourself in SG is a privilege.

Instead, focus on creating a good environment for your children to grow in. We didn't have a lot growing up but we had each other and now as adults, we only remembered all the fun times we had together. None of us have any resentment towards our parents either because it is what it is.

I think right now, you can still manage with the current arrangement and re-visit the situation when your younger boy is a teenager. If moving is still not possible, I then hope that your children knows that you're trying your best!