Question: My spouse is self-employed and has significant expenses that he can write off, eg home office expenses. For him, itemized deductions makes total sense compared to standard.

I'm also working from home (remotely) but I'm an employee so apparently I can't claim home office expenses as deductions (weird). Therefore for me, itemized deductions make no sense compared to standard.

My income is much higher than my spouse's, so I'm guessing we will file jointly. It would make logical sense to me that we could add up the standard deduction for my income and the itemized deductions for his income to calculate our total deductions, but I'm not reading anywhere that this is a possibility: can someone please confirm that this is not possible? Any advice on what to do in our situation? Many thanks.

Answer: 
The standard deduction for married filing jointly is 2x the standard deduction for filing single or married filing separately.

When filing jointly you either itemize or take the standard deduction jointly. Even if you filed separately, if one spouse itemized the other would have to too (well, they don't HAVE to but their standard deduction would be 0).

Self employment expenses are not itemized deductions, but instead offset business income, so itemized vs standard is likely a non-issue for you. If your spouse is new to self-employment it's worth doing a fair bit of research on what is/isn't deductible and/or leveraging a professional.
It is not possible. If you file separately, you have to both either itemize or not.

However, if your spouse is self-employed then their home-office deduction goes as an expense on their Schedule C, not as a deduction on schedule A. That should solve your problem.