Aesthetics
It is important that the spaces do not appear institutional and sparse, while also not creating too much visual complexity.
Art
Art can alleviate stress and improve mood and comfort level by providing a distraction or escape from an individuals emotional or psychological state. Natural views such as landscape imagery are associated with positivity and comfort. Paintings that are symbolic or have imagery that could trigger negative emotions or feelings should be avoided.
Color
Light, cool colors such as blue, green and purple, should be used to create a calming, spatially open environment. Deeply hued and warm colors such as red, orange and yellow are more likely to arouse negative emotions.
Furniture
Furniture can be used to create a sense of safety and independence alleviating negative emotions and perceived crowdedness. Avoid face-to-face seating across from a desk or table and rather encourage sitting corner-to-corner which is far less confrontational. Situate seating in waiting areas so that the individual is facing out from sheltering walls.
Lighting & Daylight
Natural light and rooms with windows, even if the blinds are closed, appear to be more open and inviting. Keep in mind that the quality of lighting can impact moved and perceived safety. Give individuals control over the lighting in the spaces they are in, increasing their sense of control and autonomy.
Plants
Plants and vegetation, whether live or decorative, connects individuals to the natural world which reduces stress, promotes peace and tranquility and enhances self-esteem.
Spatial Layout
Ensure that the space is perceived as open, fostering clear sightlines and very few barriers. This will mitigate the perceived sense of crowding easing emotional stress.
By employing principals of trauma informed care like those above, gives the design of a space the ability to aid in healing and comfort of individuals who have been faced with physical or emotional trauma.