A favorite answer of consultants on almost any question is “that depends”. In this case, it depends mainly on your budget and composition of your staff.
Keep in mind that nowadays are so many alternatives to getting your own office space – from office sharing, to working from home, to working in a library or even asking around to see if you can borrow some office space for free. Especially if you are solo, it should not be hard to find a place you can quietly do your work. Good internet connection can be found in a lot more places and sometimes that is all you or your team needs to have a productive day.
All that said, if you have the budget, a good number (4+) of full-time employees that live within the same vicinity, having a space where you can build a shared vision together could really help you build a strong foundation. Do try to avoid a long-term lease, just in case you need to shrink or grow.
For a non profit just starting out, you will likely be asked about your overhead. Somewhat arbitrary non profit overhead benchmarks shouldn’t prevent you from getting office space if you believe it will really help you grow initially, but do be ready to justify why it is needed. Try to secure overhead funds for an office space from donors such as board members who know the cause intimately and are convinced having an office can help you grow.
So, in conclusion, if an office space is merely to make you seem more legitimate rather than an essential foundation, it probably isn’t for you yet. However, if you really believe an office will help you grow, don’t worry about cutting costs just for the sake of cutting costs. In the end, if you still are not sure you have the funding or the need for an office, give it a go for two weeks to one month without one. Then try to see if you can rent shared office out for two weeks to a month. Compare the productivity and quality of work and then make your decision.
One final tip:
Studies have shown that working from home can be more productive, but also less creative since there is less communication and collaboration. If you do decide to have your team work virtually then make sure you are able to stay in touch. Some ideas for staying in touch can be virtual meetings with boards, using the interactivity of google docs, hosting a retreat or making use of cafes or library conference rooms every once in a while.