When I went to a client's home the other day it was expected that I would clean the pool, water the plants, monitor the gardener, etc. Would you share with me the normal scope of duties you include when house sitting? Do you sleep at the client's home? It seems that I am doing a whole lot more than just watching the dogs.
You decide on the scope of your other house-sitting duties and set your rates accordingly. I view house-sitting as a premium type service because you have to move into someone else's home and are responsible for it. Small things like watering plants and taking in mail would be very normal extras, but your focus is petcare. I think cleaning a pool goes way beyond. Since there is a gardener, suggest that he takes care of it. For $35/night, I'd limit it to basics. Whole house care should be more.
I agree with Karen. Pet care is the focus. If you're not comfortable telling the client no, suggest it has to do with your liability (which is true). Let them know that your insurance coverage only relates to damage caused by your pet care services, and could create an issue if you're doing more than light house work. Pool damage is costly if not cleaned properly (even if a rare instance), but your insurance may not cover the damages. At the meet and greet, ask what is expected of you around the house. If something falls outside of the scope of light plant watering, cleaning up after yourself and the pet, etc. you can say something along the lines of:
"I'd be happy to help you with your pet and home. Unfortunately, to keep my costs low, my quoted price only reflects pet care and light house duties needed to maintain your home's cleanliness."
You can also then suggest a cost increase for extra duties (if you're comfortable!)
I also agree with Karen. When it comes to house sitting, you can decide how much or how little to take on, then set your rate accordingly. When I have house sat, it has been overnight and for a lengthy period, i.e 10-14 days. I did some light housekeeping, dust vacuum, laundered the linens and towels I used, as I was basically living there. I wanted the client to come home finding their home in the same condition as they left it. The client offered the use of their pool to me, so since I was using it, I did take care of it (top it up with water, add chlorine when needed, clean the filter basket). I also watered their garden & collected their mail.