Beyond-green buildings: Focusing on the health and well-being of a building’s occupants
Nowadays the term “green building” doesn’t only stand for energy efficiency any more. A modern, intelligent building has to provide a healthy and comfortable environment. After all, we spend about 80 to 90% of our lives indoors.
Occupant well-being and satisfaction can’t be achieved by only meeting the minimum requirements, both depend on physical and psychological factors. The WHO’s definition says: “Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.”
A number of factors effect the overall perception of the living and surrounding environment. And similarly to achieving energy efficiency, the building needs to be seen as a whole as many aspects effect other areas. A healthy building provides:
- Ventilation and good indoor air quality
- Prevention of moisture, mold and pests
- Thermal comfort: Reliable heating & cooling
- Noise reduction
- Natural lighting and pleasant views & aesthetics
- Privacy & Security
- Manageable costs
Ventilation and good indoor air quality
Standards for Indoor Environmental Quality (IEQ) include humidity, ventilation rates and exposure limits for air pollutants. Indoor air quality can either be controlled naturally (windows) or artificially (air conditioning systems).
Building-related illnesses related to poor indoor air quality are: CO intoxication, allergic diseases like asthma and rhinitis, sensitivity to chemicals and respiratory illnesses. The effect of poor indoor air quality further depends on intensity, length, and source of noxious exposure.
Measurements of indoor air quality are based on the intensity of the ventilation.
Ventilation is a fast reacting systems, so changes can take place immediately. Indoor air quality is closely related to thermal comfort as well as moisture control.
This is very obvious but take a moment to picture the inside of your duct system, especially if you live in an older building. Sure these systems have filters but the amount of dust, fungus, rodents, rodents’ feces, insects, etc. can be frightening.
Air quality is also effected by appliances in your home, especially your kitchen can become a quite hazardous place. Stoves and ovens using gas for example add to air pollution, can cause serious accidents, and should really be a thing from the past by now. All-electric appliances and equipment (as part of building electrification) solve this problem because they are safe and clean. The same of course applies to fireplaces and outdated heating systems that use oil or gas.
All air quality measures of course depend on reliable air sealing including modern windows, since that’s the only way to control the indoor environment, e.g. making sure air pollution from the outside can’t enter the home.
Another outside intrusion can be Radon that enters the building from below. A safe way to prevent this is a crawl space encapsulation.
Prevention of moisture, mold and pests
Directly related to air quality is the presence of moisture that can enter your home. It creeps into your building, working its way through walls and causes all kinds of bad news like mold, fungus and spores. Once this happens it normally is a long and expensive process to get everything dry and even then air quality and the insulation of the home might never be the same. And of course, water damage can immensely lower the value of your building.
Next to obvious parts to consider like roof, walls, ventilation, and heating are foundation drainage, basement sealing and a crawl space encapsulation. The latter of course also prevents rodents, critters, and insects from entering the home.
Wooden structures can become critically unstable and unsafe due to water damage. While exterior structures like decks can be repaired and rebuilt rather easily, wall structures, basements, and attics take much more work to fix.
Thermal comfort: Reliable heating & cooling
To achieve overall satisfaction with the indoor thermal conditions, heating, cooling and air conditioning systems are used to control temperature, humidity and air velocity. Technologies controlling thermal comfort are slow-reacting technologies, meaning their adaptation takes some time.
Three variables influence the thermal comfort perception: the climate, the nature of a building (and its services) and time (defining the rate at which the changes occur to which one has to adapt). Increased temperature leads to a higher concentration of harmful substances in the air originating from fixtures, meaning that there’s a high dependency between temperature and air quality.
We have been installing mini-split systems for heating and cooling for a while, the results are more than satisfying: The units are quiet, all-electric, require no or minimal duct work, and temperature changes occur quickly.
Acoustic quality and noise reduction
Acoustic comfort is often described as an acceptable level of noise. But the perception of sound is more complex, depending on sound intensity, temporal and spectral features, and individual perception.
Acoustic satisfaction is a state of contentment with acoustic conditions; it is inclusive of annoyance, loudness, and distraction. However, there is no standard definition neither for acoustic quality nor acoustic comfort/satisfaction. A good acoustic environment is typically associated with the isolation of unwanted sounds and presence of pleasant sound.
Acoustic quality in buildings is influenced by sound insulation and sound absorption. Sound insulation of a building’s shell, roof and windows is important to keep unwanted outdoor noise out (e.g. traffic). Sound insulation of floors, walls and doors needs to be considered when indoor sources (neighbors’ noise, air-conditioning units) are present. Once a room is insulated, room acoustic aspects come into attention. Sound produced inside a room can be enhanced due to multiple reflections.
Noise causes distraction, stress, annoyance, leads to fatigue or can damage your hearing. Even lower sound levels might affect human health if exposed to for a long time, causing insomnia. For the indoor sound environment, sound level and speech privacy belong to be the most important factors. Finally, neighbor noise might also cause health problems. Chronic exposure to noise can cause a variety of health problems, such as hearing impairments, hypertension, cardiovascular problems, sleep disturbances and annoyance. Noise exposure can also have psychological effects such as stress and decreasing cognitive performance and attention.
Visual Comfort: Natural lighting, pleasant views and aesthetics
A well-designed lighting system provides adequate illumination to ensure safety and enable movement. A significant part should be provided by daylight, offering a view to the outside, which contributes to the psychological well-being of the occupants – a direct relationship between natural daylight and health has been proven over and over again. Insufficient light can disrupt the biological rhythm, which can have an impact on health, safety and performance.
A significant relationship between view type, view quality, social density, and perceived discomfort has been reported. This is also supported by findings of the HOPE project of positive statistical correlation between view and comfort. These have been identified to have a positive effect on human psychology, sleep quality and mood.
Lighting and solar shading systems are considered fast-reacting systems, a change can happen immediately. They are also low-energy consumption systems. Still, it can account for up to 25% of the total building’s used energy – here, solar panels lead a major reduction in costs.
Privacy and Security
Home is a place where we need to feel safe, secure, and have privacy.
Part of security is also the ability to move easily and safely. Make sure to maximize free space and optimize the movement through rooms.
Manageable Costs
An important contributor to well-being is not worrying about building and maintenance costs, as well as utility bills. Dreading the monthly payments without seeing a way to better the situation by saving energy is a constant dark cloud hanging over you. An energy retrofit is a one-time investment that pays off later.
Regarding new buildings: Nowadays building a net-zero, energy-efficient home doesn’t cost more than a conventional home. You’ll benefit from modern, future-proof techniques for decades, raise the value of your home
