house ownership - does this sound fair

[isthistoonosy]

OH inherited our house in a very poor state, and spent 60k and several years renovating it. In the next few years we plan to renovate his mothers house and move in there, this will paid for as a family expense.
The house we are in will then hopefully be rented out for approx £500 pcm. I plan to pay OH half of his renovation costs (30k) and then any rental income will be split between us equally.

Neither us know how we should deal with ownership of the houses if we were to split up. He inherited them originally so even with equal payments to the renovations it feels he should own more than half.
Does me owning a third of each house sound fair to us both?

Not enough information here.
Length of the marriage. Etc feels relevant

Are you married? If not, get a valuation at today's prices, and your £30k can buy a share. If it's valued at £150k, your share would be 20%. Paying half the renovations is irrelevant as they have already happened and been paid for.

We aren't married, been together 8 yrs. I've paid a fair share of the household bills during that time but no rent / mortgage as he didn't have any debt on the house. We took equal parental leave with both kids and take roughly equal days off for kids sick days, nursery pick ups etc.
The norm here is 50/50 care of the kids in the case of a relationship splitting up. I wouldn't stay living in either of the houses.
I'm not sure what else would be relevant.

What country are you in?

Sweden

Oh! I thought your answer would be important re Scottish legal system vs England & Wales.

You really need to take legal advice in Sweden as to the best way to document your agreement, whatever that is.

No-one here can say if 1/3 is reasonable because we don't know the value of the property!

I'm with Kaniel - work out the market value and what % of that your £30K would be - and that's what you own. But get it all done through a lawyer.

Oh that's fine I know how to get the papers legally drawn up.
Valuation approach seems fair though.
I guess something similar for the house we move into, get a valuation before and after works to work out the percentage owned by each of us. So 50k before, 100k after we own 75%/25% each.