I would love the opportunity to get your dog out of the house and down to your local park!
I also offer pet sitting at the owners house, I decided on this based on the fact that it is the most comforting and well known place for the pet, and is less stressful on the pet to be in a new place.
We can discuss prefered times/days, how long you wish for the dog walk to take (I am more than happy to sit them for the day, so long as this is organised well in advance to the scheduled date)...