Your figures sound about right, based on my experience.
In London, the cost per employee I’ve used is £15k pa. That includes office space and maintenance, taxes, plus IT costs, entertainment, HR, etc.
The cost for fully remote employees is £9k pa. That is, the cost of the office is £6K per employee.
There are additional costs for remote employees, like remote support. But these balance against not having to buy office furniture, pay for cleaning, etc.
But in London you have to pay those employees more if they're paying to commute (and wasting hours of their day on the packed trains every day), buy food in the city, etc.
I really can't see it being worth it in massive, overpriced cities.
Absolutely, there are hidden costs, in both directions.
If you only hire within the pool of people who are willing and able to commute to your office, you'll both need to pay more and have less choice. Workers are more tired as they spend hours commuting every day.
On the other hand, it's harder to develop juniors if all your seniors are working from home. Written communication lacks context that helps difficult conversations move forward. Silos build up as people in different teams never see each other.
In the long-term, I believe the broader benefits to society and the planet mean fully remote working will become almost universal. In the meantime, a hybrid model of mostly remote with broadly-attended meetups is the best combination. But some companies will decide that everybody being in the office all the time is right for them, and they can perhaps leverage some benefits of doing so.
It depends too much on the details to give a definitive answer.
Assuming the "typical" company made up mostly of people who've been there for more than a year, and where commuting is easy, maybe every 3 months is enough. New teams (even within such a company) should aim to meet weekly while they're in the forming stage. Small companies made up of very experienced ICs perhaps never need to meet at all.
I guess the best way of working it out is to ask people, and review what works.
I didn't personally calculate it, or see exactly how they came to it. But I know it included things that all employees need, whether remote or not, plus a few things specifically needed by remote employees. For example:
* Laptop
* Accounts like email, Slack
* Entertainment (e.g. Christmas party)
* HR (this covered specific HR services like payroll, not the whole thing)
The taxes I mentioned are part of the cost of running an office - especially local government taxes ("rates" in UK parlance).
The £9K figure _doesn't_ include taxes on individuals, such as NI and pension contributions. That comes from a different budget, and is typically an extra 25% on top of salary.
I lumped a few costs onto that, which aren't taxes, but are tied to salary. Pension contributions, life insurance, health insurance, for example - these all come out of the same budget as national insurance contributions.
In London, the cost per employee I’ve used is £15k pa. That includes office space and maintenance, taxes, plus IT costs, entertainment, HR, etc.
The cost for fully remote employees is £9k pa. That is, the cost of the office is £6K per employee.
There are additional costs for remote employees, like remote support. But these balance against not having to buy office furniture, pay for cleaning, etc.