  A Digital Twin is a virtual system that can fully describe a physical one. It
constantly receives data from its counterpart's sensors, consults external
sources, and obtains manual inputs from its stakeholders. The DT uses all this
information to make various computations, such as analyses, predictions, and
simulations, and then possibly sends the results back to the physical system.
Domotics, or Smart Home Technologies, brings intelligence and comfort to a
house by automating some of its functions. Although the research on both themes
is vast, there are few implementations of Smart Homes based on Digital Twin
technologies, and this work aims to prove that residences can also benefit from
this concept. We implement two different use cases showing that a two-way
connection between a home and its virtual counterpart can provide its owners
with analyses and simulation-based automation. The first study case allows the
user to visualize their home appliances' past and present state concerning
their energy consumption. Based on heating simulations, the second determines
the best time to turn on a heater to increase the home's thermal comfort and
reduce energy usage.
