Unless you know the people very well, I would be careful with work trade situations. We had an awful experience a couple years back where we built a yurt on someone's property in exchange for 8-10 hours of work a week. The problem was that the landlady couldn't come up with more than an hour of work to do at a time, and got upset if there was nobody around to work at any given time, so we were constantly in her debt, and one of us had to hang around the place at all hours to be available if she needed us. Basically, it became a full time job, and prevented my partner from looking for other work. We moved as soon as we could.
The power imbalance with a work trade can be tremendous. They are both your landlord and your boss, and the hassle to move can be really large, so it is almost always easier in the short term to comply with their crazy demands, or hour inflation, or miscalculations of hours worked, or whatever. It is harder for you to dissolve the relationship than it is for them.
On the other hand, we have a partial work trade set up on our current situation, but there are two big differences: we pay rent and then have money knocked off when we work for them (housesitting, in this case), and we knew the people weren't batshit when we moved in. i would never do straight worktrade again, and instead would recommend paying rent, and then being paid for your work, even if you end up balancing it out to nobody owing any money each month.
