Teardrops n Tiny Travel Trailers

I am looking for a space to rent in the Nashua, NH or Lowell, MA area for the 3-4 months of winter in order to build a teardrop trailer. The space must meet the following criteria:
-a door greater than 6ft wide through which a light (600lbs?) vehicle can pass.
-a space no less than 8ft wide along said door and 12ft deep.
-lighting, in order to work
-an electrical outlet
-access evenings and weekends
-reasonable expectation of security.

I can pay rent.

You can try a local storage facility. Some offer spaces to do what you need.

Another place is a community workshop, or "Makerspace" http://makerspace.com/makerspace-directory as they are known. There is a build thread where someone built their trailer at one, and the Makerspaces are all over the country now. If you are a communally-minded person, that might work for you (I'm a loner, but I would try it if I didn't have places to "work on it" around here; I paid the price-in time- of starting my build 50 miles from home). It might work for you, though. There's a Makerspace in Cambridge,Ma.