Healthy Buildings

In recent years there has been a growing trend to tightly insulate a building to reduce the structures heat losses and requirements for heating. This is the right thing to do as it helps to reduce the whole life emissions of the building, however a building should be designed such that it is environmentally friendly in production and in use, but and is also a healthy building to live or work.

The issue with this is that in doing so, the building is unable to breath effectively resulting in poor Indoor Air Quality as pollutants build up within the space, therefore systems must be used to avoid these issues.

Indoor pollution causes thousands of cancer deaths and hundreds of thousands of respiratory health problems each year.

The result of buildings making occupants feel unwell is often referred to as, “Sick Buildings Syndrome.”

The NHS sets out that the key symptoms are headaches, nausea, fatigue, poor concentration, shortness of breath and skin and eye irritations.

Schools and offices tend to be particularly bad for Sick Buildings Syndrome.

Key reasons can be poor ventilation, high temperatures, low humidity and airborne particulates.

What is a healthy building?

A healthy building is one that considers the environment of its occupants living, working, or studying in it.

A healthy building is one that does not impact on its occupants are health, happiness, or productivity. With regards to schools, a healthy building provides a better learning environment, where children are happy and can learn most effectively. With regards to offices this ensures the highest level of productivity and low levels of sick leave, which in turn provides businesses with financial incentives for ensuring a building is healthy.

There are seven factors that affect a persons well being:

• Air

• Water

• Nourishment

• Light

• Fitness

• Comfort

• Mind

The average person spends 90% of their lives indoors and the design of a building affects the air quality a person is breathing, the amount of light that they are getting and their thermal comfort.

What are the key areas that Engineers can focus on to Make A Healthier Building?

Natural and Artificial Lighting- Ensure spaces provide the required lux levels, giving workers control of their lighting generally has a positive effect on staff happiness. Avoid glare, contrasts of amounts of the amount of light between spaces and consider the colour of light. Natural daylight is usually desired in all spaces. Building Bulletin 90- Lighting Design For Schools states that day-lit rooms typically require a daylight factor of 5%.

Indoor Air Quality- Provide adequate ventilation rates, allowing fresh air into the space, filtration of incoming air in areas of poor outdoor air quality, suitable extraction systems in bathrooms and locations where chemicals are being used. Control of indoor temperatures through suitable ventilation, shading and in worse cases cooling (either using phase change materials, or mechanical cooling systems).

Thermal Comfort- Generally through good building design and orientation, the use of correct levels of glazing, thermal mass, shading and natural ventilation, then mechanical cooling systems are not required. Phase change materials can be used when there is minor overheating issues in certain areas of a building. In winter ensure that supply air is tempered to avoid cold draughts.

Acoustics- Minimise use of fans, minimise noise entering from outside the building, minimise room to room noise transmission.