It is important to realise that the future house we are presented with represents a level of technological sophistication that had meant that the need for humans for the house to continue running smoothly is completely done away with. In spite of the complete absence of any humans in the story, the house carries on with its normal routine, day in and day out, with robotic voices announcing the beginning of the day and a steady program of activity occuring throughout the hours. Food is cooked automatically, and then the plates are cleaned automatically too. Housework is done by robotic rodents that come out of holes at appointed times:
Out of warrens in the wall, tiny robot mice darted. The rooms were acrawl with the small cleaning animals, all rubber an dmetal. They thudded against chairs, whirling their mustached runners, kneading the rug nap, sucking gently at hidden dust. Then, like mysterious invaders, they popped into their burrows. Their pink electric eyes faded. The house was clean.
Thus, in its normal functioning, the house can be compared to a human in the way that it has a set program of activity that it follows to achieve its end goal of keeping the house in order. Perhaps we can find a similar parallel in the way that the house malfunctions because of the fire, and the robots behave in a frenzied way, such as the cooker making breakfasts "at a psychopathic rate" shows. Under dangerous and stressful situations, humans can likewise do crazy things. However, at the end of this story, both the house and the human species are eradicated.
In There Will Come Soft Rains, Ray Bradbury used personification to make the house seem alive and very much in control of things. The house makes sounds humans would make. Look at how it awakens the people, look at when the kitchen makes food, look at the cleaning that occurs, and children's hour in the nursery. In each case, the house actually talks or acts in a way humans would - sleepy, angry, paranoid (when the bird lands on the window), excited. The house takes charge of every facet of the humans' lives as well as the pet dog -- had they still been living there.
At the end of the story, the house takes on a nervous, frightened persona. The house screams, "Fire!" The shutters "snap shut" demonstrating feat. As "angry" flames move through the house, the mice "squeak" and run around aimlessly. Also, as the house "dies", a pump sighs and stops and the sprinkler system ceases. Eventually, the attic brain "dies".
There are many, many more examples of personification throughout this story. Look for the things the house and things in the house "talk", and how how house and its belongings demonstrate a variety of emotions throughout.