Loft conversion - 1 or 2 rooms

[Hall84]

We bought our house intending to convert the loft into extra bedroom space as although the living space is much better, the bedrooms are curious at best! We've had some rough guestimates and at the moment can either have 2 rooms of 3.5m 4m or a master suite that's 74m. The shower room/ensuite won't impact these dimensions. At the moment there's me, DH and 1 DC. We may have a second child if that's possible but nothing set in stone as yet. We've 2 big bedrooms on the first floor and 2 much smaller rooms we use as offices (hybrid working). Our families do live a long way away so I'd like to keep a spare double if we can (the office spaces don't allow for this). Would you have 1 or 2 rooms in the loft? TIA

I can't change the bold now:
3.5m by 4m
7m by 4m

We had ours built as one but with the electrics and radiators set up so we could easily convert to two with a stud wall. We’ve kept it as one though as we love our big master bedroom! The kids have the two double bedrooms downstairs!

One incorporating a dressing room/area. Assuming you keep the 2 small box rooms as offices, your dc stays where they are and your current room becomes the spare room. If dc2 arrives then they can bunk in with dc1 to free up their room.

One

We’ve gone with 2 with en-suites because we already have another master bedroom with ensuite and walk-in wardrobe. Similar measurements to yours.
If we didn’t have that, I’d make it the master suite.

We had a similar debate - our loft conversion is starting is June. We've gone for 1 room because we felt that with the sloping roof, having two rooms might make them feel small, even if the floorprint is actually ok. On the first floor, we have two double rooms (1 x spare / future DC2 and 1 x DC1) plus a tiny boxroom that is a shared office (we alternate when we wfh so that only one of us ever needs to use the office).

We've just gone for one really big room.

Potential to rejig if needed one day, but right now I bloody love my massive bedroom/en-suite/dressing room.

It means we have a 'wow!' room instead of two nothing rooms. No regrets.

I love the idea of a big 'wow' room that has the potential to be split but with a practical head 2 rooms may impact the loan to value ratio enough for remortgaging as we come off the next fixed rate.
If it helps at all current bedroom dimensions:
15ft by 12ft
17ft by 10ft
7ft by 5ft twice that are the office spaces - one is slightly bigger at the moment but will shrink to allow for stair space.
Thank you for your thoughts

@NewHouseNewMe how did you get 2 ensuite rooms if you don't mind me asking?

We put them each side of the bedrooms in the slopped part of the roof, with pocket doors save space. They’re not the biggest in the worst but enough for sure.
It would have been hard to pick which DC got the ensuite If we hadn’t!

In a previous house we had the master in the attic. It was lovely and had a good view but I didn’t like the kids being below me and closer to the front door etc. Maybe another thing to think about?

By the time you've put wardrobes, bed and a dressing table/desk into 3x4 there's not much room left. I'd go for one big principal bedroom in the loft, unless you are planning to put 2 DC up there in future.

I have two small doubles and it works well for me.

Even with a hypothetical 2 DC in the loft I'd consider leaving a dividing wall optional. My sister redid her loft with a view to putting a (slightly claustrophobia-inducing) wall in later - beds are built under the eaves on both sides to maximize space. Turns out now her 4 DC are battling it out ferociously which 2 of them get to share the still-open loft - the latest is oldest DD gave up her share to DS 3 as a 12th birthday present. ( Sharing with DD 14 as not in UK, they don't mind a bit and no emotional scarring so far).

We had two bedrooms, a box room and a shower room. We didn’t intend moving up there but it gave us lots of space for visitors. DD lives up there now and has a lounge and a bedroom and the box room has become an office.