Comfort

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Building better is not only about avoiding problems, it should also be about creating positively pleasurable and healthy living places.

Comfort is about the physical environment in its totality. The issues which are most obviously associated with comfort are:

• Temperature
• Humidity
• Noise
• Light
• Smell
• Temperature and Humidity:

Human beings operate and feel better when they are at temperatures which are comfortable. It is now well understood that in the workplace, accidents increase as temperatures go outside the zone of 16 to 24°C. However temperature is also strongly linked to humidity levels as regards comfort as the chart below indicates.

In the section on health, controlling humidity and temperature was seen as a method of controlling pollutants . Interestingly the levels of humidity and temperature which are most healthy are also the most comfortable. There is no conflict between health and comfort.

Noise:

In addition to temperature and humidity, acoustic isolation is also very important for comfort. There were 313,000 complaints in England and Wales to Environmental Health Officers about domestic noise disturbance in 2004, up from 155,000 in 1999 and from only 31,000 in 1980 . As a result of the growing number of complaints and the potential litigation arising from these, building regulations have considerably improved acoustic insulation requirements since 2002. Testing is now mandatory if robust details are not used. However there are still a number of problem areas, and many building systems which have been designed for good thermal performance will not necessarily be good from an acoustic point of view. This applies particularly to lightweight structures. Certain types of thermal insulation can actually be bad for acoustic insulation, by increasing noise reverberation and flanking sound .

The point to note with regard to acoustics is that this is all about getting the shell of the building right in the first instance. It is extremely difficult, if not impossible to retrofit proper acoustic performance.

Lighting

Lighting can have either a positive or negative effect on health and well being. The effects may be felt immediately or only in the long term. There are four types of effect: light as radiation, light acting through the visual system, light acting through the circadian system and light as a purifier.

Generally natural daylight is understood to be beneficial both to health and well being. Maximising good daylight in housing is therefore an important consideration. Good daylight means levels of daylight which are sufficient to see properly without glare or excessive contrast. Too much direct sun can actually cause discomfort and ill health, particularly with highly reflective surfaces.

On the other hand darkness is also an important source of wellbeing. Our bodies require a regular cycle of light and darkness for both physical and mental health. Bedrooms need to be dark and quiet for most people to receive proper rest. Psychologically it is also important that the outside is also dark, wherever possible. Light pollution is now a commonly accepted problem in many built up areas.

Building better means taking the quality of lighting, particularly natural daylighting, seriously. It is not just the conservatory on the back of the house, but a strategy for the whole house, to bring in good natural light without glare, too much contrast or overheating. This also saves energy and money.

As regards artificial lighting, issues of radiation, glare, contrast, and flicker are all crucial for health and comfort. Although lighting is an important consideration from an energy point of view, health and comfort should not be sacrificed for low energy strategies. From both an energy and a financial point of view this is short sighted, as ill health and lack of well being have huge environmental and financial consequences. However just as with humidity and temperature, with proper understanding and good design there is no conflict between energy and health in the area of lighting. A strategy to maximise the benefits of daylight, along with well designed low energy lighting will provide the best solution for health and comfort and the lowest impact on the environment.

Smell

Substances that enter the nasal cavity may be sensed either by the olfactory senses or by the limbic system. The first is responsible for odour detection, the second is sensitive to irritants. On the whole people adapt to odours relatively quickly, whereas irritants can get worse the longer exposure continues. Furthermore many of the irritants are at levels where they are not detectable as odours.

On the whole when building well, the objective should be to eliminate odours and air borne irritants of all kinds. There are some “natural” paints and other decorating materials which utilise natural essences such as citrus oil. The pleasant smell is often seen as a selling point, but it should be noted that many people have extreme allergic reactions to citrus essence, and furthermore that it will react as a VOC with other chemicals to produce low level ozone, which is a danger to asthmatics and those with respiratory problems.

The main ways of dealing with odours are outlined in the TM40 document in order of importance as follows:

• Eliminate contaminants at source
• Substitute with sources that produce non-toxic or less malodorous contaminants
• Reduce emission rates of contaminants
• Segregate occupants from potential sources of toxic or malodorous substances
• Improve ventilation
• Provide personal protection

It is obvious from this that the most important strategy is reduction of the problem at source. From a building point of view this means the use of non- odorous substances wherever possible, ie materials without VOCs, which are commonly used in many paints, glues, composite products, preservatives etc.

It may also be noted that certain types of material and certain types of construction are able to absorb odours and neutralise them. In particular unfired clay products (as used in boards, blocks and plasters) and protein based products such as sheepswool (as used in carpets, furnishings, and insulation) have proven absorptive qualities.

Next: Building Durability