Friday, June 12, 2015

What constitutes a 'healthy' home?


Health is really important to all of us, yet many of us live in houses with poor internal environments. Some of this is our own fault - we clean using dangerous chemicals; we allow properties to get into a poor state and hence introduce damp from rain; we don't ventilate properly; etc. However, some of it down to the structure of the building. So I thought that it might be worth investigating the idea that using health as opposed to pure energy efficiency could be a way forward for improvements in the housing sector.

So what are the key health factors that could be used to drive new specifications for home improvements?

Allergies

People seem to be getting more sensitive to substances, many of which are airborne. So there is a need for better Internal Air Quality (IAQ) in our homes. Having filters in ventilation systems is an obvious way of improving the situation for cleaning any air coming into our homes, however most properties do not have whole house ventilation systems, but there is a trend towards positive pressure ventilation in retrofits. These units can have filters fitted, but it does mean that they have to be cleaned / maintained on a regular basis and so this means that we have to have a system in place to ensure that this actually happens (otherwise it is waste of money and resources).

Many materials continue to off gas substances throughout their lives, so it usually better to use natural materials that have been treated with natural preservatives / protecting coats.

The main source of allergies, though comes through from our foods and the effects of our lifestyle choices. This could be the type of cleaning materials that we use, whether we smoke in the house etc.

However we can reduce dust circulation by using radiant wall heating rather than conventional radiators or underfloor heating.

Respiratory diseases

Respiratory problems are caused by a range of root causes many of which can be tackled during refurbishment. Issues like high / low humidity, mould and dust can all be effected by what we do to our homes.

It is really important that we manage ventilation in our homes as this helps to control humidity, but it is equally important that we allow any breathing walls to continue to do so. Sealing up older 'moist' walls can introduce damp and hence mould etc. Having a relative humidity of between 50 and 60 per cent minimises the risks associated with dust mites etc and this range can be maintained by the use breathable solid walls. We must also be careful when installing insulation, as poor fitting / specification can introduce cold spots and this in turn can easily create damp / mould issues.

Automatic ventilation control systems that run off information like relative humidity and CO2 levels can really assist with maintaining a good internal air quality. These can be installed where there is a good airtightness in the building and ideally systems would also have heat recovery built in.

Temperature related troubles

Overheating and underheating can cause or exacerbate serious medical conditions, so again we must ensure that properties do not get too hot, or too cold. So design is really important to make sure that properties can cope with the projected changes in climate which suggest that our weather will get more extreme in the future, especially with hot conditions. Unless of course the Atlantic Conveyor gives in and we might then become much, much colder in the winter.

So must ensure that properties are designed for both. Using high thermal capacity insulations like woodfibre boards and batts can assist with this. Being able to create homes that can easily and cheaply maintain a comfortable 19 degrees C in both summer and winter is important.

Highly efficient heating systems need to be used that are appropriate for the type of house, so care is required to specify the best type of system. Some houses only served by oil and electricity, others gas etc, so the most efficient systems need to be specified and this might involve additional works. For example ground source heat pumps (GSHP) only work well at low temperatures and so a well insulated house with managed ventilation is required here. A very efficient GSHP in a poorly insulated and draughty home will be very inefficient.

Mental health

Now this is a real bag of worms. Issues like stress can come from a wide range of factors that can be designed out (or into) our buildings. Common factors that effect stress at home include:

Money worries - making our homes cheap to run is really important (as long as we don't cause lots of 'unintended consequences' at the same time). So installing systems that improve energy efficiency, reduce water consumption, minimise maintenance costs, prolong maintenance intervals etc. is really important. Renewable energy systems that attract support can also help to relieve financial pressures by providing some free energy, but also a small income. However, it should be remembered that people make choices when it comes to spending their money and it may be that the best ones are not always taken.

Families - families don't always get along and having separate spaces can be useful. Knocking through reception rooms to make large spaces may not be the best solution. Sound proofing between rooms is also important to create more private space. Having bedrooms that are acoustically isolated can make sleep better and this can be really important.

Neighbours - again neighbours can be a source of comfort or stress. Whichever it is, having good acoustic barriers between the two houses is important. It is also important that any thermal improvements to one house do not cause problems with any adjoining property. So care needs to be taken here.

Natural light - a lack of natural light effects many people, especially those suffering from SAD and so it is important to ensure that light is maximised. This might mean using sun tubes, roof windows etc.

Worries about safety and security - using good quality doors, windows and fixings, combined with clever design can create homes that both feel, and are, more secure. 

Alleviation of niggles - of course there are no end of these, but some are avoidable: Alleviating pressure drops in hot water when more than two outlets are being used; use of long life bulbs to reduce need for replacement; easy access to water stop-cocks if there is a major leak; isolation valves on water outlets for easy routine maintenance; use of siphon toilets rather than valve to stop constant leaks; use of metal rainwater goods to reduce water damage from leaking or damaged plastic ones; use of breathable paints on breathable walls to reduce re-painting requirements; no drylining allowed to reduce issues associated with just hiding problems etc etc.

Conclusion

When we start to think about our homes in more detail one realises that we need homes that feature:
  • Good, well controlled, ventilation (e.g using CO2 and RH controls)
  • Appropriately insulated both against heat loss but also heat gain (e.g  use of wood fibre insulation)
  • Minimised the use of water (e.g pulse shower heads, variable siphon flushes etc.)
  • Take advantage of any appropriate renewable energy generation potential (e.g FiT and RHI measures)
  • Minimised use of energy (e.g LED lights)
  • Have good acoustic insulation both between houses and within them (especially bedrooms)
  • Have a mix of private and public space 
  • Have sufficient natural light (e.g using sun tubes etc.)
  • Are free from risk of damp and mould (using correct breathable materials)
  • Use natural materials that are less likely to off gas toxic substances (e.g wood)
  • Use materials cleverly to minimise maintenance requirements (check compatibility of materials)
  • Use good quality materials that provide long term solutions to safety and security (good quality doors, windows and locks)
Now all of that is a tad more involved than indiscriminately slapping on EPS external wall insulation and changing a boiler, however if we start to think more about maintaining a good, healthy internal environment then maybe we can reduce costs on the health service as well as providing better housing for the great British public.

The British Thoractic Society estimates overall costs to the country of £6.6 billion due to respiratory disease (or which Gov. says £1 billion is spent annually by the NHS on chronic obstructive Pulmonary Diseases)




So improving our homes will not eradicate these costs, but it will have some effect. So we can either look to continue doing 'improvements' that only tackle a small fraction of the issues facing our stock (and even this we are doing badly in many cases - and this causes more stress and more long term financial costs to the country) or we can start to create a nation of healthy homes.

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