Janus is also important for architects, since he resides on the thresholds between past and present, old and new, and inside and outside. While a threshold can be simply a transition from one space to another, a threshold can also symbolize enlightenment, and the movement between stages in our lives. Thresholds not only allow the ﬂow of air, but also suggest the possibility for ideas to pass between past and future. Janus is also concerned with transition and ambiguity, since a threshold is not entirely inside or entirely outside, and may be considered as neutral or noncommitted. Thresholds play a part in beginnings and are symbolic in traditions such as marriage where crossing a threshold celebrates a couple’s new life together. Janus therefore represents the potentialities and possibilities of the future.