The communications infrastructure must also looks outwards, connecting with the world at large.
As with energy above, a building may have multiple links to multiple ISPs to guarantee the resilient connectivity (and business continuity) it needs.
In fact data connectivity has become so vital that buildings are increasingly being rated on it, affecting rentability and attractiveness in the real estate market.
And plainly, external connectivity will continue to raise its own questions around Internet security and resistance to cyber attack.