1. Introduction

In the evening, a man comes back home. As he steps into the house, the lights turn on in the living room. In the kitchen, the sunlight is still strong enough and the lamps stay off. While he is browsing through his mail, the faint click of the windows upstairs is heard. The air in the bedroom has just reached the optimal temperature and it would get too cold now that the sun has set. He moves to the kitchen and reads on the fridge display: the milk inside has gone beyond its expiration date but its organoleptic and nutritional properties are still unaffected. Instead, it is time for the fruit in the bowl on the counter to get replaced, the display shows. At this point, he could recall on the display a variety of data: the temperature and humidity of each room; the pressure of his car’s tyres; the status of the wine ageing in the cellar; whether water or any fertilizer is required in the garden; even the structural integrity of the house itself.