What is a Healthy Home?
Florence Nightingale actually summarised the main points for a healthy environment:
” Pure Air, Pure Water, Efficient drainage, Cleanliness and Light. Without these, no house can be healthy”
Today we could present health and wellbeing in the built environment in a multitude of different ways – most usefully summarised by the “WELL Standard” with 120 different categories. The UK Green Building Council also has a very useful info-graphic which I have reproduced below.
In my opinion the Victorians in some ways had design and architecture right – the buildings were light and airy – the advice was to open windows in the morning and light a fire in the evening once a day. Then as we recognised the need for energy efficiency – saves you buying all that wood and coal – we made buildings progressively more air tight and draft proof. We also started reducing window sizes and using highly insulating (plastic based materials) to prevent heat loss.
Inadvertently the main downside has been a reduction in ventilation and light, particularly in poorly designed modern homes. The plus side has been increasingly efficient and convenient modern central heating over time.
I am going to summarise a few key points here:
Lighting
There has been some evidence of lack of exposure to light and subsequent health effects as well. We spend 22 hours a day inside buildings on average in the UK. Inefficient lighting can double the risk of that feeling we haven’t got enough energy. Interruppting our physicall connection to changing daylight leveles outside (‘circardian rythrm’) is linked scientifcally with a wide varierty of health affects from cardiovascular, immune system to mood and learing problems.
Understanding light is complex, as timing, exposure level, amount received and type of light is involved, but a basic rule is daylight is best – avoid intense peaks of it etc but a sensible sufficiency is required.
LIGHTING
'Enough' Daylight
Ventilation
‘Open air’ schools and sanatoriums etc have understood the value in fresh air supply for a long time. We need air in homes for breathing but primarily to reduce contamination of pollutants and regulate the internal environment.
Too much CO2 (from breathing out) can induce a sleepiness and sluggish feeling- try a stuffy office or poorly ventilated bedroom.
The link between high humidity and increased build up and subsequent exposure of dust mites and mould is the main problem. At too low levels some viruses can survive and thrive longer. Also our eyes and skin can be irritable and mucous linings can dry out – this potentially causes increased risk of infection.
VENTILATION
40-60 % Relative Humidity, <1000ppm CO2
Temperature
It is well known that being too cold is a bad thing for your comfort, well being and health. Increasingly we are dealing with over temperature, especially in modern builds. It is a serious problem: too hot to sleep on a warm night will seriously affect you makes you tired etc. These can make your immune response diminish making it harder to fight off illness. Different people ‘feel’ temperature an comfort at different rates- the very young and very old are most at risk. As a rule if your house falls below 16C the risk of damp mould increases as relative humidity increases. Above 26C it can be overheating and uncomfortable if not dangerous for vulnerable persons.
TEMPERATURE
16-24 C
Ancillary Services
Foul air from sewers and so on are physically isolated from your property by ‘traps’ in the drainage system for sinks, toilets baths etc (e.g. the U-Bend).
Sinks and toilets should be operated every 3-4 days -this prevents the traps (U-bends) drying out – this can be identified by the stagnation and associated smell pretty quickly.
SERVICES
Operation & Maintenance
Conclusions
The link between temperature, air supply and light is keenly seen in various sleep deprivation studies.
Keep your trickle vents open- I know in winter they get shut as they feel drafty, but its important to keep some airflow in rooms.
Key steps here are to windows to open to allow ‘cross ventilation’ allowing open windows on either side of a building storey. this increases ventilation at peak demand (‘boost’) events and you can get ‘free’cooling most of the time in the Scottish climate.
Also set up your heating controls effectively- the Thermal Regulating Valves in radiators typically give 20’C at setting 3.
A healthy home should provide a good physical well-being, but also promote mental and “spiritual” wellbeing or happiness. The relationships are complex but good designers and clients can encapsulate all of these factors.
References
CIBSE (2020) https://www.cibsejournal.com/technical/preventing-covid-19-spreading-in-buildings/
Saint Gobain (2020) https://multicomfort.saint-gobain.co.uk/appg-white-paper-building-our-future-laying-the-foundations-for-healthy-homes-and-buildings/
Ade, R (2020) Pers. Com. https://www.linkedin.com/in/rochelle-ade-1b130116/
UKGCBC (2016) https://www.ukgbc.org/sites/default/files/08453%20UKGBC%20Healthy%20Homes%20Updated%2015%20Aug%20(spreads).pdf
Baker, N. & Steemers, K. (2019) Healthy Homes: Designing with Light and Air for Sustainability and Wellbeing. RIBA:London
WELL (2020) https://www.wellcertified.com/
