The BER-faced lies - our inaccurate energy ratings
Eithne Tynan explains why our energy ratings system is not at all so hot on accuracy
IT may be the start of summer, but with temperatures early this week at a cool 12C, it's a little too soon to pack away the winter coats and turn off the central heating.
At the beginning of this month, the Government doubled the carbon tax to €20 per tonne of carbon dioxide, adding around another €1.20 to a 40kg bag of coal, and focusing people's minds yet again on the ever-escalating cost of keeping warm at home.
By law, all new houses – and all existing houses being offered for sale or rent – must have a Building Energy Rating (BER).
On paper, this is supposed to give you a good idea of how energy-efficient the building is, and hence how much it might cost to heat it.
And because every buyer now looks for one, your BER rating is therefore generally expected to have an impact on the value of your home.
But just how accurate are Building Energy Ratings?
Do they represent a reliable guide to the real energy consumption of a house?
And if you're buying, selling or renting a place to live, just how much confidence should you have in its BER, and should that rating influence the value of your home?
BERs are based on the energy used for heating, ventilation, water heating, and lighting a home.
Consumption is measured in kilowatt hours per metre squared per year and is rated from A1 to G. So an A1-rated house uses 25 kilowatt hours per square metre per year or less, and a G-rated house uses more than 450.
The Sustainable Energy Authority of Ireland (SEAI), which is responsible for implementing the system, likens it to mpg on a car, which measures consumption only, without taking into account driving habits or terrain.
So whether you, the householder, actually turn the heating on full blast and swelter in T-shirts all year round, or huddle under blankets at 15C, doesn't actually matter a jot.
However, did you know that the BER software, known as Dwelling Energy Assessment Procedure (Deap), is based on the rather expensive principle that the occupants of the house want to (or could possibly afford to) heat all the rooms in the house to at least 18C and the main living areas to 21C, for eight hours a day, seven days a week.
According to the latest figures from the SEAI, most Irish homes fall into the C and D BER categories. And the highest number, 54,936, are rated D1.
Believe it or not, a meagre six of the country's 411,986 dwelling houses had an A1 rating.
The SEAI also supplies a rough guide to the heating costs associated with each rating and the variations are extreme. For instance, an A1-rated semi-detached 1,600 sq ft house should theoretically cost €280 a year to heat.
A house of the same type with a D1 rating – the most common energy rating – would set you back €2,600 a year in heating bills.
Even more frightening, the cost of heating a detached, G-rated mansion of 3,200 sq ft could be as much as €7,900 a year, according to the SEAI.
So far so telling. But many architects and property experts are extremely sceptical about the reliability of these ratings.
And estate agents and valuers say that, despite the apparent evidence of drastic home heating costs such as the above, buyers are paying little or no attention to BER ratings because they don't believe them, they don't understand them, or they don't think they're important.
Jeff Colley, editor of 'Passive House Plus' magazine, cited the example of Ireland's first certified passive house, which was built in 2004 and yet only received a fairly average BER rating of C1. However, in practice a certified passive house consumes energy at a rate of about 15 kilowatts per square metre per year – well within A1 range. A 'passive house' is a home which has had its air leakages cut and its insulation levels cranked up to super strict standards as laid down by a German-based organisation. The passive house institute will not allow you to use the term unless your home not only complies with its uber tight regime, but also unless you have had its notoriously rigorous inspectors around to insure that it does what it says on the tin.
In terms of energy efficient homes, passive houses are the champs.
"The Deap software that creates Building Energy Ratings really struggles with low-energy buildings, buildings with virtually no heating requirements," said Colley. This suggests that it's possible for a house to behave better, in energy-performance terms, than its BER indicates it should. In most cases, though, it's likely to behave worse. Colley said one of the main problems with BERs is that the assessor assumes your house complies with the building regulations in place at the time it was built.
So ratings are based on how a house was supposed to have been built, not on how it actually was built.
It's not easy, for instance, for a BER assessor to check whether external wall insulation is as it should be – not without doing some damage to a property. Yet a 2005 study commissioned by the SEAI itself revealed that the majority of homes constructed during the boom failed to comply with energy performance requirements – 70pc had missing insulation, for instance.
"This is down to consumer awareness of what a BER is. It needs to be taken with a large pinch of salt. If people are falsely under the impression that a good BER really means lower running costs, then they could get stung," said Colley.
CJ Walsh, a consultant architect and member of the Irish Building Control Institute, has been writing blog posts on the shortcomings of the BER system for some years now.
"I would say that the connection between a BER certificate and the actual energy performance of a real building is extremely tenuous," said Walsh.
"It's standard software that's used and the problem is that not everybody who uses the software has a solid understanding of what a building is supposed to do.
"Instead of having a good look at the construction type and putting in the right values in the software, they'll put in a 'default' value."
'Default' values can lead to misleading ratings. For instance, if you have no evident method of water heating, the assessor is required to follow the instructions in the DEAP manual and "assume direct electric heating as the main water heater".
So what about the effect of BERs on potential buyers and tenants?
Perhaps surprisingly, Keith Lowe, chief executive of DNG, said the ratings were having no effect whatsoever in the secondhand house market.
"Nearly all the BER ratings on second-hand houses are on the floor, and it's quite easy to increase them without having to spend a lot of money. Plus there's so much competition for housing especially in Dublin at the moment that it's not even a consideration," said Lowe.
Similarly, Patrick Davitt, chief executive of the Institute of Professional Auctioneers and Valuers, has seen BERs used as a bargaining chip in the rental market. He said: "People might use the BER to try and negotiate down the price if they're renting something. They might say it's not worth what you're looking for for it." But similar to Lowe, Davitt doesn't think BERs affect capital valuations for second-hand property purchases.
"If it's a G rating, people know why it's a G. It's because it's an old-fashioned house that's going to need work done to it anyway. But if it's the difference between a B1 and a C1, who calculates what it's going to cost extra to heat it? Nobody does."
Davitt believes the SEAI has not done enough to educate the public on what energy ratings are all about. "Instead of just advertising the certificate they should advertise what it means to people – what is the difference in heating costs and how it's worked out. People just don't understand about it."