You didn't mention how old this person is or where you live, both of which would make a difference.
First of all, I'd be wary of accepting the label of autism for a person who is deafblind unless they were diagnosed by someone with considerable experience in deafblindness... many behaviors characteristic of autism (language delay, self-stimulatory behaviors, social problems, lack of eye contact, challenging behaviors, etc.) are also very common in people who are deafblind and could be completely caused by the dual sensory impairment. Whether the behaviors are caused by autism or a result of the deafblindness is important because it would change how you address the behavior.
If you are in the U.S., the best step to take would be to contact your state's deaf-blind project. Every state has one, and part of their job is to provide technical assistance to care providers for people who are deafblind. Find your local project's contact info here: http://www.nationaldb.org/ppStateDBProjects.php.
I've had experience with a few different states' projects, and from what I've experienced, they typically will send out an expert to meet with the deafblind person in one or more of his natural environments, observe, and then provide suggestions to the people who work with the deafblind person. They're able to do this at regular intervals (varies depending on the state, but once per year is pretty common) due to federal funding. They'd be the best resource to provide individualized help.
From your description, your client's behavior sounds very normal to me. You moved her to a new environment that is unfamiliar to her. When you can't see or hear, the world can be a scary place, and it takes time to learn about your surroundings and feel safe. She felt safe in the old building; she knew the people, where everything was, where she could move, where she could find her favorite things, and she knew exactly what to expect. In a new building, she has to re-learn everything from scratch. She may not even know if her new building is the size of a one-room cottage or a 100-story skyscraper. Her chair is familiar territory: not only does she know the chair itself, but it provides her with tangible boundaries that she can feel while she's in it (it's the same size, shape, and texture it always has been; it didn't magically transform into a 100 story building without reason). She feels safe there and knows what's going on.
How does she communicate? Does she sign, speak, use tactile cues, use pictures, use real objects? What's her cognitive level and ability to understand complex and abstract language? Did people explain to her about the move and prepare her for it before you transferred buildings? Has she gotten a tour of the entire building and been re-introduced to all of her materials and anything new? I would start with that as an activity if you haven't done it yet. Give her a multi-sensory tour of the new building, letting her touch, smell, and see and hear (to the extent she is able) all of the different areas of the building. She may need to re-learn how to wash her hands if there's a different type of faucet in this building; She may need to re-learn how to dress herself if her clothes are located in different areas; she may need to develop new favorite places and activities based on her experience in the new surroundings.
The main priority should be helping her to understand her environment, what is going on around her, how to interact with the world, and how to communicate effectively. Specific activities are hard to suggest not knowing this person's age, abilities, interests, strengths, cognitive level, communicative abilities, etc.