When opening a photography studio, you must make a significant initial, and then monthly, investment in your space. To justify these expenses to investors in your business plan, show how you will utilize the space to its fullest. It represents one of your major assets, and renting such a studio while explaining in your plan that your shoots will primarily be out on location shows poor planning on your part to funders.
Consider what customer markets you should pursue to keep the space booked up with your own shoots as much as possible. This will likely be the highest revenue-generating use of the space for you. Look for the customers that freelance photographers without a studio are unable to gain and market the strengths your space will offer. By investing in some additional backdrops or decorative elements to dress the space, you can expand the options of shoots you can accommodate in-house significantly.
Can part of your studio double as an office space during downtime? If you can limit your need for separate office space you may be able to cut down on your rent, if you can plan for this before signing a lease.
If your lease allows it, you can also rent out your studio to other parties while it is idle, as long as they are for legal uses. This can be for small parties and events or shoots by other photographers, for example. Be sure that those you rent to carry their own insurance to lower your risk and that your agreement with them further limits the liability you take on from their rental.
For every day you rent your studio out to another business or individual, you will bring in revenue, but you will also incur an unseen opportunity cost. For example if you rent your studio out for a day for $500 two weeks in advance of a date and then you must turn down a shoot that comes up for that day only for which you would net $1,000, you have effectively lost $500 rather than earned it. Only experience will teach you what rates are reasonable to cover the probability of last-minute shoots coming up.