Are You Too Energy Efficient?
We live in an ever more energy conscious world.
The deterioration of the environment has prompted governments the world over to tighten emission regulations, increase sustainability legislation and press for greater energy efficiency.
The upside of this ideological shift is that homes are being built in a more environmentally conscious way. Energy efficient technologies are making it cheaper and greener to heat homes and A++ windows keeps it that way.
For developers this is a two edged sword.
On the one hand, energy efficient homes follow current regulations making it more straight forward (if not easier) to build.
It also makes them easier to sell as consumers are becoming far more aware of the importance of energy efficient windows, energy efficient heating and even things like carbon neutral concrete.
On the other, homes that are too energy efficient can harm the occupants.
Homes, be they houses or apartments, are dynamic systems that require the right amount of ventilation to prevent things like damp from occurring. However there is also the build-up of harmful pathogens and chemicals to consider.
Indoor air pollution is a real issue and without steady ventilation individuals in ‘air tight’ homes can experience headaches, frequent colds and sore throats, skin rashes, eye irritation, lethargy and in some case dizziness, and memory lapses.
Many of these can be caused by a build-up of waste gases from gas or solid fuel fireplaces, boilers/water heaters and gas firing ovens & stoves. Usually produced in trace amounts, they pose no threat to human life in properly ventilated homes.
Without proper ventilation these gases can build to fatal levels over time.
Other impacts on these homes can include moisture on windows, dust mite infestations and a stuffy, unpleasant environment.
The good news is that tests are available to determine if homes are too airtight.
However, there is another, far more sinister, by-product of an energy efficient home.
Since the drive towards energy efficiency that began in the mid-sixties regulations has evolved around a minimum standard for the thermal envelope. Or to put it another way, how much heat should be wasted from homes during the winter.
However, there is no threshold for how much heat should be retained. This means that homes are getting hotter during the summer than is safe for human habitation.
The elderly, the infirm and children are particularly at risk as they are likely to be indoors during the hottest periods of the day.
Public Health England released a report that suggests by 2020, an additional 1,700 people a year could die as a result of extremes in temperature. This is on top of the 2,000 people who die from heat related illness every year in the UK.
Air pollution levels are usually higher in hot weather – often due to the stillness of the air – which can create a pressure cooker environment in the home causing a host of health complaints that could prove fatal.
The question is simply: what can be done?
Depending on the scale of project the answer can be footpaths that reflect heat or bigger green spaces and trees that create a cooler space.
Large trees naturally cool the air around them because leaves transpire water so placing these around developments can help.
From a design standpoint, concrete floors and night time purge ventilation can help to keep developments cool.
Solar shading or heat reflective finishes are all ways of keeping the house cool in the summer without compromising its heat efficiency in the winter.
The challenge is not knowing which methods work in which combinations so the answer may be initially to look to overseas neighbours who have more experience coping with higher temperatures.
Regardless, the issue of overheating persists and at the current rates will continue to worsen so building contingencies into your designs now is both cost effective and marketable.