I've been going into people's homes to photograph them all my career. Initially for newspapers and magazines and latterly for my family portraits.
Working in surroundings familiar to the subject can have real benefits in making them feel much more comfortable and at ease than they might otherwise do in a photographer's studio. But unlike a studio where the light and surroundings are all totally controllable, you never know exactly what you're going to find and you have to work with what you've got.
This family from St Albans had a beautiful house and the light was great so no worries there but the little chap above has complex medical challenges and to capture his smiley personality and the glint in his eye it was important for me to be the "visitor" to his house rather than him being the "visitor" in the unusual surroundings of a studio.