I believe we create the sanctity of temple in our mind and no more is necessary........but if you are like me your left brain likes some feedback in the physical and its fun besides. I remember our yoga classes, we'd push back the furniture, throw down our mat's and the energy would shift - the family room became a yoga studio! My point is that dedicating a space shifts the energy to align with intention. You can find various rituals to sanctify the space on the Internet and how to build one using Sacred Geometry but I find that smudging/cleansing then intent to dedicate plus warding* the cardinal points works fine. Remember though, while I am suggesting how to create sacred Temple space this also works in reverse. Continuous repeated use of a space for spiritual, ritual, or Lightwork will sanctify an area as well. The fact that I work in my temple is a privilege to me, actually the entire room is an interactive sacred machine similar to my altar, which shares this space as well. While it's true the Temple is within, still when I enter my designated temple space my focus shifts to Purpose, dedicated to The Mission working with Nature Intelligence and it is automatically interactive. As I greet my sacred space, it greets me right back.
*Warding: To ward or guard. You might visualize guardian angels at the four cardinal points-North, South, East and West.