Happy people have a few things in common, studies have found – some of these things transcend to their similarities within their homes!Less mess – Psychologists have determined that our environments are powerful predictors of our happiness – too much clutter and “visual complexity” equates to stress.
Social space – They make their homes more inviting and open – grills for BBQs, areas for game night, and furniture arranged in a circle so guests can talk and gather with one another.
Plants – Studies indicate nature and plants produce calming affects in people. Peace lilies are great low light interior plants that help recycle indoor air.
Sentimental items – Meaningful objects that give people happy feelings obviously make them… well, happy! Pictures of people and fond memories, mementos that bring you joy, are all common themes in homes of happy people.
Wall color – Color can influence your mood. Happy people trend toward calmer, more positive mood-boosting colors that are less bright and more relaxing.
Source: http://www.rd.com/home/cleaning-organizing/be-happier-at-home/