Internationally, there is still a considerable short-fall in the take-up of energy saving measures in the home and the main reason is that energy is comparatively cheap. Replacing existing windows with double glazing has been popular, more for cosmetic than environmental reasons. So, why bother? Here are some of the reasons.
(1) At the time of writing oil prices are rising due to uncertainties about security of supplies from the Middle East, particularly centring on Iraq, which has the second largest reserves of oil in the region. At the same time, we are being continually reminded that reserves of oil and gas are finite. According to some analysts, the year 2003 will be the time when demand for oil outstrips supply, irrespective of a possible Middle East conflict. The more optimistic oil experts put the date at around 2005-7. For the UK the situation is exacerbated by the decline in North Sea oil production and the fact that gas reserves in this area will be exhausted by about 2016. Add to this the fact that most nuclear generators will have been decommissioned by roughly the same time and the problems are particularly acute. Price rises would therefore seem to be inevitable. If there is a widespread conflagration in the Middle East the price rise could be astronomic, triggering a world recession led by the USA. This is one very good reason why nations and individuals should minimize their reliance on fossil-based energy.
(2) As if this were not enough, global warming resulting mainly from the burning of fossil fuels is building up momentum. Almost each day there is evidence of climate changes and the situation is effectively irreversible. Even if human-induced emissions of greenhouse gases are levelled off immediately, the momentum in the system would continue to inflict climate damage for decades, even centuries to come. However, if things go on as they are, there is no immediate prospect of stabilizing those gases. The Johannesburg Summit of 2002 deliberately ignored the climate change issue, focusing on sustainable development. From the point of view of most governments and multinational corporations it is ‘business as usual’ which, according to the UN scientists is the worst case scenario (Intergovernmental Panel on Climate Change (IPCC) 2002). Without going into detail, the main driver of climate change is the concentration of carbon dioxide (CO2) in the atmosphere. This acts like a blanket, reflecting heat from the sun back to Earth which acts as a heat accumulator. Before the Industrial Revolution the CO2 concentration was around 270 parts per million by volume (ppmv). Today it is approximately 380 ppmv (Washington Worldwatch Institute, 2003). The UN CO2 abatement programme has an upper limit of 500 ppmv by 2050. It recognizes that at this level there will be considerable climate damage by flood, storm, ecological and social disruption. However, this target assumes that the world should have already adopted significant carbon reduction policies. There is still no sign that this will happen; the present shape of business globalization seems to guarantee that business as usual will prevail for the foreseeable future. If the big players prefer to ignore their responsibilities for the future welfare of the planet it is up to individuals to take up the challenge.
The effect of this could be dramatic. In the UK nearly 30 per cent of all CO2 emissions are down to housing. This could quite reasonably be cut by half using the technology which will be outlined in this topic. New homes are subject to reasonably stringent energy efficiency standards; it is the existing stock of homes which present the challenge, in particular those of private home owners and landlords.
(3) The pressure to upgrade our houses will soon come from the authorities. By 2005-6 regulations will come into force in the UK designed to speed up the home-buying process. A vendor will be required to provide a ‘home condition report’ based on a professional survey which will include an energy efficiency assessment (EEA) of the property. As energy prices rise, the EEA will increasingly become a deciding factor in a decision to purchase. At the same time a European Union directive ‘Energy in Buildings’ is likely to be incorporated into UK law by 2006. This states that houses over 10 years old must have a valid energy certificate at the time of sale.
(4) The upgrading of a property should immediately represent added capital value. At the same time, energy bills could be reduced by as much as 50 per cent per year. As prices rise this represents a valuable revenue gain. According to the government English House Condition Survey, over 85 per cent of pre-1965 housing has no wall insulation. It is no surprise then that up to 60 per cent of energy used in the home is expended on heating.
(5) What tends to be overlooked is the health impact of poorly insulated homes. Many householders endure inadequate room temperatures sometimes as low as 14°C which, for the elderly and infirm, is a major hazard. Of the 55 000 extra winter deaths which occurred in the UK in 1999-2000, up to half may be attributed to inadequate warmth. In addition, that winter there was a sharp rise in respiratory and cardiovascular illnesses.
The official standard for warmth in a living room is 21°C and in other rooms 18°C. About 25 per cent of homes in the UK achieve these levels. The minimum temperatures from the point of view of health are 18°C for living rooms and 16°C for other rooms. A government house condition survey for England found that, when the outside temperature fell to 4°C:
50 per cent of owner occupied homes
62 per cent of council homes
95 per cent of private rented apartments
all failed to reach the minimum standard.
Poorly insulated homes are not only cold, they are invariably damp. When warm air comes into contact with cold external walls it condenses into moisture. This, in turn, encourages mould growth which poses a serious health risk. This is a particular problem for the fuel poor. This is recognized by government: ‘The principal effects of fuel poverty are health related, with children, the old, the sick and the disabled most at risk. Cold homes are thought to exacerbate existing illnesses such as asthma and reduce resistance to infections (Fuel Poverty; The New HEES, DETR 1999).
(6) What should also be factored in is the rise in comfort which can be experienced from investing in an insulation and draught-proofing strategy. Cold, uninsulated walls and single-glazed windows cause sharp thermal gradients which are often experienced as cold draughts. Condensation adds to this problem. This is particularly the case with uninsulated floors leading to the warm head-cold feet condition that is especially uncomfortable for people with poor circulation.
(7) Finally there is the matter of social responsibility. As mentioned above, it is becoming more evident that the welfare of the planet will increasingly depend on the actions of individuals and local communities. Upgrading one’s home is not only a personal act of social responsibility, it may also stimulate the ‘keeping up with the Jones’ phenomenon. In addition there is the point that if a number of householders decide to upgrade simultaneously they may reap the financial benefits of bulk purchase through a large contract.
The house condition survey
A house behaves as an interactive system; all its components impinge on each other. For example, it is pointless achieving a high level of insulation in walls and roof if 40 per cent of space heating is lost through leakage. So, before undertaking a retrofit programme of insulation, etc., it is necessary to survey the property to gauge the extent of the work to be undertaken so that the procedures can be planned in the correct sequence. It is also wise to make an estimate of costs including a 10 per cent contingency sum. This will involve calculating areas, for example of the area of glazing which may need to be replaced. At this stage it is worth investigating the grants and ‘green’ mortgages that may be available from building societies. If routine maintenance is having to be undertaken, such as the replacement of roof tiles/slates, the cost of using it as an opportunity to insert or enhance insulation is a relatively small extra cost burden achieving a rapid payback time.
It is not always obvious to a householder whether or not the walls are solid or cavity construction. As regards the latter, if there are not records from previous owners, it will be necessary for the cavities to be inspected to see if insulation has been inserted. If there is such evidence, the next thing is to ensure that it is still viable up to eaves level. There is a tendency for fibrous insulants to settle over time.
It may be that there is some insulation in the loft space. However, it is most likely to be inadequate, on the basis that the loft is the most cost-effective zone in terms of the benefits of insulation.
Most older houses are draughty which can be a benefit in summer and an escape route for up to 40 per cent of heat in winter. Draught problems need to be identified and dealt with as the first priority. A really effective draught-proofing procedure must be linked to the need to maintain adequate ventilation. This will require specialist advice and will be covered in topic 5.
The opportunity should be taken to inspect the structural integrity of the property. Evidence of damp or cracks in walls must be attended to before installing insulation. Roof flashings should be inspected and replaced where necessary. At the same time, gutters and rainwater pipes should be in good condition. Damp walls are not only a cold bridge, they can also cause some insulation materials to lose efficiency.
Special attention should be paid to finishes, selecting paints and varnishes which are free of volatile organic compounds (VOCs).
Finally, it is important to ensure that all operatives hired to carry out retrofit work are validated by their respective trade or professional bodies and that all guarantees are robust and free of small print escape clauses. In certain instances permissions may have to be sought under Planning and Building Regulations legislation. In the UK under the 2002 Building Regulations Part L, certain aspects of retrofit work must comply with standards of insulation. This will be explained in detail in the text.
At the outset it is worth considering which are the remedial measures which are cost effective in terms both of monetary cost and CO2 emissions. There is little doubt which leads the field: loft insulation. Heat rises and a poorly insulated roof offers the perfect escape route. Also it is worth enquiring if grants are available at a particular time and the body to clarify this in the UK is the Energy Saving Trust. Its details are given below. At the time of writing the UK government is giving priority to persuading home owners to upgrade their properties, and money is often what makes the argument irresistible.
Straightforward draught-proofing can have a benefit out of all proportion to its cost. However, if the draught sealing has been carried out really effectively, it may be necessary to provide fan-assisted ventilation which can also recover heat from the warm expelled from the house. The power consumed is no more than a couple of average light bulbs.
Most post-1930 homes have cavity walls and still the majority in the UK do not have the benefit of cavity-fill insulation. The benefits of rectifying this deficiency can be felt immediately in increased comfort, as well as longer term in lower energy bills. Grants may be available. Refer to www.est.org.uk
Many central heating systems are well below current best practice. Upgrading the system starting with thermostatic valves fitted to radiators which set the temperature at a level which is appropriate to a room. For example, the radiator in an entrance hall does not need to emit heat at the same temperature as in the living room. The next move is to replace the boiler with a condensing version, an operation which might also attract a government subsidy.
Appliances and white goods are often major energy drains, especially fridges and freezers. When these come to be replaced it is vital that the most energy efficient products are selected. The additional cost of a highly energy efficient item could soon be recovered in lower running costs.
Double glazing has gained a hold on the housing sector, not least because of the assertive marketing tactics of some double glazing companies. In part, this is because it is perceived as a fashion accessory to a home. It certainly improves comfort by reducing the temperature drop within two or three feet of a window which is usually experienced as a draught. In terms of energy saving, depending on the area of glazing involved, the pay-back time can be quite long. Building regulations now require high performance double glazing which uses Low-E (low emissivity) glass.
Cold feet is a national malaise in the UK because floors are also a major heat drain. Inserting insulation into floors can be relatively cheap and easy if there is access to the underside of the floor. If not, there is probably no alternative to raising the floor boards.
Next in the hierarchy of cost comes insulating solid masonry walls. Insulating the inside face of external walls is the cheaper option, but is does involve reducing the floorspace, as well as relocating power sockets and light switches. However, the really significant results are achieved with external insulation or overcladding. Big results incur fairly dramatic costs, but most of these may be recovered in the increased capital value of a highly energy efficient overclad property, remembering the incoming regulations concerning an energy report as part of the seller’s pack.
At the time of writing (January 2003) the UK government has announced a subsidy scheme aimed at home owners to encourage the installation of renewable energy systems like photovoltaic cells (PVs). Grants may make home energy production a viable proposition. In Europe, it will almost certainly be much more cost effective when the energy market is liberalized under EU regulations later in the decade.
In one or two cases indicative costs are given as a rough guide. In times of economic volatility it is hazardous to indicate prices. Wherever possible contact names, web sites, e-mail addresses and telephone numbers are given within the text.