How do I get the spark back after being too close for too long?

I'm 25, my 27 year old girlfriend and I have been together for just over a year. Despite discussing how much we wanted to respect each others' independence during our brief courtship, we ended up basically co-existing at my house for the first six months. Twice I asked her to voluntarily give me more space; I wanted her to feel welcome in my home and I didn't want to have to be forceful or mean about it, but she just didn't honor my request. Our relationship has diminished in closeness since then, and I have recently told her that I need some time to myself, which she is not taking lightly or without resentment. I just want to give us the chance we didn't give ourselves at first: to get to know each other and also to let ourselves reflect on the profound way that we can move one another. How can I communicate this hope to her effectively, while maintaining respect for my space? She just seems to have a negative mindset about it, but I think that's tied to poor delivery on my part.