I feel like I could write a novel on this. Pardon my scattered-ness.
The answer to your question is ethereal at best. A big portion of figuring out how often you need “Staff” is to determine how high touch your community will be. Is it important to you that every person be greeted, that drop in visitors get a tour? You and the other owners should view yourselves as members first and owners second. Maybe you decide not to be open to the public? After 2.5 years, I cut off the ability for people/strangers to drop in on us and require an appointment for any visitor while members have 24/7 access. We found that this minimized the interruptive nature of visitors (since our tours are kind of long and involve doing intros to EVERY person in the space). Requiring appointments allows our staff to group people into tours, which is valuable in its own right for immediate connections. In 5 years, I’ve maybe had 10 people try to pop in on us and its usually solved by them calling me and me explaining they need an appt. My staff and I like this setup b/c we can better able chunk out our time and we know what chunks of time to block out on our own calendar in case a tour is requested.
Is your space fully “serviced” or partially serviced or not serviced at all? This is probably best discussed with your members. Early expectation setting around who is responsible for what and how often will minimize sadness and resentment. If everyone knows the restrooms get cleaned 1x/week, then everyone can be on the same page. Conversely, if you promise to clean the restrooms every day then that’s the new expectation and you better find a way to maintain that 
Cohere has a nice mix of owner responsibilities, staff responsibilities, member responsibilities and contractor responsibilities.
Here’s a smattering:
Owner-billing, invoicing, making connections, 1/3 of tours, event planning, weird things that come up, big supply purchases, landlord stuff (15-30 hours/week spread over 3 locations). Caveat: I have all kinds of systems in place like Cobot, Zapier, a book keeper etc that make me more efficient than I was when I started.
Staff-tours, tidying up, introducing people, telling owner stuff (2 hours/week over 2 locations)
Members, tidying up, meaningful greeting with each other, 1 member gets a lower membership to handle every day supplies like cream and toilet paper and taking out the trash
Happy to answer even more granular questions if you have them. /ramble
Angel
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On Monday, May 18, 2015 at 11:57:23 AM UTC-6, Karen Ruane wrote:
Ah yes, that info. would help! Our space is 2400sqft. It’s a bit different in that much of this space will be in the form of art studio space, reducing our membership drastically. We plan to have about 9 resident members, and another 15-20 drop-ins. Out hope is to have about 10-15 people in the space each day.
Thanks!
Karen