This has been further emphasized the hansard and roger ulrich

Mahmoud, H. (2012). Interior Architectural Elements that Affect Human Psychology and Behavior. [online] Press.ierek.com. Available at: https://www.press.ierek.com/index.php/ARChive/article/download/112/40 [Accessed 28 Dec. 2019].

Another very important factor they should understand is eye functions when perceiving the light some researchers believe that Full-spectrum light provides the prophylactic viral and infections(staph) and also helps in improving the physical work capacity by reducing the pulse rate, which helps in lowering the systolic blood pressure and also increase the oxygen uptake. Designers should be very careful about the light and their effect on their design as it impacts physically, emotionally as well as mentally. Apart from this, they should also consider the climatic conditions of the space for example if the woodwork is been used in the room, it will give the feeling of warmth and comfort similarly tabletops of glass make the room appear larger. The successful design for achieving the happiness and welfare depends on how the designer balance between the most dominant factors such as flexibility, privacy, safety, community interactions and adequate space should be given due weight, it is believed by the researchers that the satisfaction and the psychological status of the user is directly linked to the well-planned design and its feature that make the spaces more beneficial and usable some of the researchers also believes that functionality can also encourage the user to work effectively, it is believed that flexibility and feasibility of the design can have a direct impact on the psychological and physical comfort of the user some of the examples are equipment such as fans, switch should be placed where they are easy to locate and operate, there should be sufficient lighting in the kitchen, bathroom and washing area, etc. For flexible design, it is very vital that the design is able to utilize the space in the best way and to its potential, that is we can see many furniture pieces designed with folding features and drawers with the electrical feature, etc. Another parameter that the architecture and interior designer should be kept in mind is the safety and health consideration by adapting to the design which can control the temperature and they should also consider the material which is used in the spaces such as floor covering, fainting etc. Some of the example related to the health concern such are adopting the comfortable furniture which should have a healthy design, stairs should have appropriate width and it should have adequate lightening with strong railing.

References 

Grove, J. (2019). Interior design. 2nd ed.