It’s important to protect your capital investment and to be fair about splitting running costs. Absolutely.
But if you’re at the point of being so transactional about who uses the rooms more then you’re not in the right headspace to share a home together.
Your later comments re IPB insurance….. I was an IPB assessor for 16 years, and then an underwriter.
You do realise that payouts aren’t automatic, just because you’re off work? A fair chunk of claims get declined, or only paid for a short time and then terminated even though the claimant is off work?
And as for your partner getting a new IPB policy - not everyone can get cover. Their medical history, occupation, and/or hobbies can mean they’re declined.
Plus of course only a maximum of 60% of your salary can be paid. That might be doable for you as you earn double him, but it might mean he can’t cover 50% of the mortgage and continue to pay child maintenance.
Partnerships aren’t this transactional.
So to circle back to the start, you absolutely need to be fair about sharing costs but you’re also sharing your lives. And that means the burden and balance might sometimes sit differently, depending on life events. You’re not ready to share your life with your partner. Calculating who uses rooms more is possibly the most miserable thing I’ve ever heard. You need to stay in your own homes for the foreseeable - you’re not even close to being ready to open up your life yet,