Green, eco, zero-carbon, sustainable: when it comes to property, does anyone really know what any of these terms mean? …
By 2016, the government says, all new homes will have to be zero carbon, and we will all be so used to superinsulation and microgeneration that a green house will once again be somewhere to grow tomatoes.
Which is great.
But, until that day, what’s an environmentally friendly home buyer to do?
There are so many shades of green home available, and so many terms being bandied around to describe them, that total confusion seems inevitable.
Below we run through some of the most common terms used, followed by a quick guide to help you get past the eco-waffle and recognise the genuine article.
1. Green and Eco Homes
I’ve put these two together not only because they are the most commonly used terms, but because often they mean the same thing – almost nothing.
They have both become generic terms that could mean anything from a house made of the mud in which it stands, to any home that incorporates modern technology to save energy.
At its best an eco or green home will generate less (or no) carbon dioxide, waste less water, and will be made of sustainable or renewable materials.
At worst it could be a house with a badly positioned wind turbine on the roof.
Although the older version of the Code for Sustainable Homes was calledEco Homes, and still applies to refurbished housing, many people use ‘eco home’ loosely and without reference to this rating system.
The word green, on the other hand, is fairly meaningless, which is why it’s one of the most popular with eco wafflers.
The point is this: look for agreed, or regulated, definitions and be wary of vague or aspirational usage in advertising copy.
2. Sustainable Homes
‘Sustainable’ is the government’s word of choice – and the term they use in their green bible, The Code for Sustainable Homes.
The code assesses properties according to nine categories and then weights these in order to rate the property on a scale from 1-6. The nine categories are:
• Surface water run off
• Waste & Pollution
• Health and well-being
You would expect a home advertised as green to attain Code Level 3 or above – indeed, it is a requirement for social housing and homes built with government money. A home achieving Level 6 would be zero carbon.
Critics point out that the Code is voluntary rather than mandatory and that a home rated 1 may meet very basic levels of ‘sustainability’. But Simon McWhirter from WWF says:
“It’s a pretty rigorous system, albeit a realistic one that acknowledges the considerable challenges we face in changing the way we build houses. While it’s not mandatory, we’re seeing more large housebuilders like Berkeley Homescommitting to level 3. We’ve got miles to go, but it’s a decent system and starts raising awareness of the non-carbon issues.”
3. Zero Carbon Homes
Zero carbon is a term that should be easy to define, but the devil is in the detail – on which the government is still in consultation with the building industry.
But basically, a zero-carbon home is one that can be shown to produce as much energy across a single year as it uses.
So, a calculation is made comparing the carbon dioxide generated by living in a house built to the minimum standards with those from a zero carbon home, which is much more efficient, and produces energy through the use of technologies like wind turbines, solar panels, photovoltaic cells and heat pumps.
In the current definition, zero carbon does not take into account the CO2 that is tied up in the materials used to build the house – so-called embodied energy.
The government is so keen on zero carbon that, until 2012, all newly-built zero-carbon homes sold for up to £500,000 will be exempt from stamp duty.
Luckily they are so few and far between (as of last summer only 13 qualified) that this random act of generosity is unlikely to cost taxpayers very much.
There are a few developers producing zero carbon homes already – Barratt Homes are currently building a zero carbon village atHanham Hall in Bristol, Rural Zed is the next chapter in the BedZed story; and Ecostessey Park in Norfolk also aims to be zero carbon.
4. Passive house
A particular kind of eco home, a passive house is a building that maintains a minimum temperature of around 18°C year round without the need for dedicated heating appliances.
The house uses the heat given off during everyday life. So by cooking, washing, even watching the TV we keep the house warm.
This isn’t the stuff of science fiction – it’s down to some very clever use of insulation to produce an airtight, mechanically-ventilated home (though you can open the windows if you really want) that is superefficient at stopping heat escaping from the house.
There are many passive houses running successfully in Europe, and a small, but growing number here in the UK.
The fundamental requirement of a Passive House is that the energy required for space heating must not exceed 15 kWh/(m2 a).
The BRE (who worked closely with the government to devise the Code for Sustainable Homes) is registered with the Passivhaus Institut in Darmstadt, Germany to issue PassivHaus Certificates for domestic dwellings in this country.
5. Home Energy Ratings/Energy Performance Certificates (EPCs)
Energy Performance Certificates, which are produced as part of a property’s HIP, rate a property from A to G in terms of energy efficiency and environmental impact.
For a property to achieve a Level 6 it should have an A for both.
However, the EPC inspection cannot be carried out until a building is finished, so if you are buying off-plan you will have to wait.
Almost half (44 per cent) of properties in England and Wales are being awarded an ‘average’, or Band D, energy-efficiency rating, according to Halifax’s first ever report on the subject.
Which underlines that, whatever about new homes, we face a huge task making exisiting homes environmentally friendly.
So What Features Should You Look For?
If you think the nomenclature of green building is as clear as a nice pile of organic mud, there are ways to decide whether or not a given development is worth looking at from an environmental point of view.
Firstly, and most obviously, you can look for the professional assessments such a Code rating or a PassivHaus Certificates.
Next you can look at the features that are being offered. These could (and probably should) include items such as:
• Very high levels of insulation (eg: a Passive house will have 350mm in the walls, compared the government’s recommended 90mm)
• Passive solar orientation (larger amounts of south facing glazing)
• Use of natural and if possible locally sourced materials, eg: a timber frame and wool insulation
• Microgeneration systems, such as solar thermal hot water heating, photovoltaic panels for generating electricity, and heat recovery systems to circulate heat throughout the house.
• Rainwater harvesting and/or greywater collection
What Should You Ask?
The presence of these features, however, is not enough. Greenwash, for the most part, involves a number of basic tactics: vagueness, irrelevant information, hidden trade-offs, lack of proof, technical jargon no ordinary person can understand, and the like.
With this in mind, Green Building Specialist Tim Pullen offers the following tips:
1. Demand the figures from the developers. Ask what the bills will be. In Europe you would be given detailed costing.
2. If the builder is saying it’s a sustainable house ask what that actually means. Ask about the materials used. If they say they use recycled materials ask for the percentages.
3. You can anticipate a good EPC rating, but ask yourself what the rating of a non-eco new build next door is. It doesn’t mean very much if you don’t have anything to compare it with.
[written for findaproperty.com 2009]
Note: we would like to express our thanks to Simon McWhirter of WWF for his help with this article.