Creating a house cleaning service like TaskRabbit: could I hire maids as contractors or is hiring them as employees required by law?

Is it required by the California EDD to hire people as W2 employees for this case or could I just employ them as contractors? I wonder how companies like TaskRabbit and Uber are able to employ people as contractors with California EDD's "temporary service employees" regulations.

You can indeed hire them as contractors and avoid bringing them on as employees. CA has guidelines by which the EDD decides if the person is a contractor, and here they are:

• If the person decides how to do the work.
• If the person already has the required skillset (you don't have to train them for the task they're going to be hired to do).
• If the person has multiple customers or clients (i.e. they could work for their own clients as well on the side).
• If the person doesn't always work at the company's location (which is perfectly satisfied in your case).
• If the person works on projects occasionally or not pre-set times.
• If the person is paid a fixed fee for a defined scope of work.

In your case you pretty much satisfy all of them. So you have nothing to worry about and can hire them as contractors without risk of being audited by the EDD.