Another type of clandestine safehouse is an otherwise abandoned or unoccupied building that is secretly made habitable. This can be as simple as having some copies of keys to some usually unoccupied vacation rental places to as elaborate as specialized shipping containers hooked up as "mini-apartments" in the abandoned factory/warehouse side of town, or even better yet, old government buildings that had originally been built sturdy as bomb shelters. Several west coast cities have old bunker complexes of varying sizes, some of which apparently can be occupied.

Think of lots of extension cords, the sort that are used to power construction sites, power generation or stealing grid power somehow, water tap-in somehow and sewage removal. Maybe the essentials for building maintenance for getting the electric and plumbing in some section of a building functioning.

Another option that I noticed can work for some people around here is rental of certain offices in building that at one time had been residential. Then it just means pressuring the building manager to make sure the showers are operational since some of your employees bike to work, and then having 24 hour access (you usually get that), and enough extra couches in the office to camp some people out.