Dear Santa, what I would like for Christmas this year is for the Australian Government to pass legislation requiring that, by 2016, every new home be designed and built to make more energy than it uses.

Is that really too much to ask?

On the one hand, if we look at the poor standard of energy performance in most new homes in Australia; or if we look at the Abbott Government’s record of doing everything possible to move in completely the opposite direction; or we think about what it might take to persuade the authorities (let alone the building industry) to accept such a dramatic shift from current practice; it would be easy to pass this off as completely impossible and unrealistic.

On the other hand, I think it’s fair to say that it is completely possible and could realistically be made to happen if there was any sort of political will in that direction. At the very least I think it’s worth floating the idea and explaining why I think it could, and should, be made to happen.

Why should new homes be energy positive when there are millions of old homes that have terrible energy performance?

On hearing about the Greeny Flat, a number of knowledgeable people have suggested that our focus needs to be on upgrading the existing building stock because that’s where the biggest portion of the fossil fuels consumed by buildings is being used. While I completely agree that it is vital to upgrade the existing building stock I also think it is vital to dramatically improve the energy performance of new buildings, otherwise we’ll be having to go back in ten or twenty years time and upgrade the buildings that we’re building now. From my 25 years of experience I can knowingly say that adding insulation or double glazing or energy efficient heating, cooling, hot water, and ventilation systems to existing buildings is much more expensive, difficult, and complicated than building them right in the first place.

I think the place to start is by ‘future proofing’ our new buildings, i.e. building them to a standard that will meet the needs of the foreseeable future. We can clearly see that, at some point in the not-too-distant future, we are going to have to stop burning fossil fuels. This means that our buildings will need to make more energy than they use. So let’s start building them that way now.

But isn’t it incredibly difficult and expensive to make a building energy positive?

In the case of commercial buildings, particularly high-rise ones, it can indeed be a very difficult and expensive proposition because they have high energy demands and relatively small roof areas (i.e. not much room for solar panels). Nevertheless it can still be possible to make a skyscraper ‘Net Zero Energy’ as the following article indicates. Net Zero Energy Skyscraper in Indonesia For the purposes of this article I would like to focus on homes in Australia where the relatively low energy requirements (due to our mild climate) and the relatively large roof areas (due to most homes being only one or two stories tall) make it much, much easier to achieve the energy positive goal.

In fact projects like the Greeny Flat and Glenn and Lee Robinson’s home in Bundanoon are proving that it can be quite easy and affordable to design and build homes that make more energy than they use. Both of these projects were built using standard, off-the-shelf materials and systems combined with simple, common-sense passive solar design. Both make about twice as much energy as they consume. And both were built on very tight budgets. I have discussed  the costs associated with the Greeny Flat in previous newsletters but the Robinson’s house is an exceptional example of affordable sustainability with a finished cost per square meter of only $1500.

Glenn and Lee Robinson’s affordable, energy positive home in Bundanoon, NSW.

So, no, it is not necessarily difficult or expensive to build energy positive homes. Yes, double-glazed windows are more expensive than single-glazed. Yes, solar power systems cost money. But if we build smaller, simpler homes (and let’s face it, there is not reason why Australians need to have the largest average size for new homes anywhere in the world at 214 sq.m and do we really need those marble benchtops from Italy?) then we can afford to add the improved insulation, energy efficient systems, and renewable energy production required to make a home energy positive.

One final point on affordability is that, if we build a home that is energy positive then the operating costs will be very, very low (so far the Greeny Flat has averaged $0.73c/day to run the entire house) which will save the occupants a fortune over the life of the home.

OK, so it can be done, but you’ll never get the politicians to agree!

Admittedly, as long as the Abbott Government is in power in Australia, it is HIGHLY unlikely that a measure like this would ever be considered. But it is worth noting that in the UK it has been mandated that all new homes are to be ‘zero carbon’ by 2016. Below is a quote from the British Government’s 2006 consultation document ‘Building a Greener Future: Towards Zero Carbon Development‘.

As a final step, we are proposing that all new homes are zero carbon by 2016 – within a decade. For a new home to be genuinely zero carbon it will need to deliver zero carbon (net over the year) for all energy use in the home – cooking, washing and electronic entertainment appliances as well as space heating, cooling, ventilation, lighting and hot water. This will require renewable or very low carbon energy in addition to high levels of insulation, etc.

Since 2006, when the above paper was written, the British Government has adopted these recommendations and, ‘a commitment to delivering zero carbon homes from 2016 was included in the Budget 2013′ (from UK Parliament Briefing Paper, Nov 18th, 2013) . The astonishing thing for anyone familiar with the Abbott Government’s record so far is that this came about with the Conservative Party in power in Britain under the leadership of David Cameron.

If the Poms can do it, so can we.

In conclusion I would like to make the case that, if the British Government under the Conservative Party can pass legislation mandating that all new homes be Zero Carbon by 2016 then there is absolutely no reason why the Australian Government could not mandate that all new homes be energy positive by 2016 too.

Now I just have to hope that I’ve been good this year and Santa will grant my wish, right?

In our last newsletter we talked about the how Passive Solar Design helps to keep the Greeny Flat cool in summer and how we can help this process by operating the windows and blinds correctly.

Another factor in the design of the Greeny Flat that has a major impact on summer cooling is the choice of colour and material for the roof.

Most people understand that darker colours absorb more heat than lighter colours. So, in order to keep a building cool in the summer, it is generally best to use a lighter colour for the roof.

The thermal mass of the roofing material also makes a difference. Basically, the heavier the material the more heat it will absorb from the sun shining on it and the longer it will hold that heat after the sun goes down. A light weight roof material on the other hand will release heat quickly once the sun is gone.

So ‘think light’ when choosing a roofing material to help you stay cool in the summer. Light weight and light colour.

It seems to be the fashion at the moment in Australia to build brick veneer McMansions with very dark tile roofs. It makes me want to laugh and cry at the same time when I see massive subdivisions of huge new homes with dark tile roofs baking in the Aussie summer sun. You know that all of those new homes have air conditioning systems which have to work much, much harder to keep them cool because they have chosen just about the worst possible roofing material.

And not only do those dark tile roofs heat the interior of the homes, they also heat up the entire neighbourhood. This is a well documented phenomenon known as the ‘heat island effect’. Basically, a lot of dark roofs and asphalt paving can cause a whole urban area to be much hotter than its surrounding rural area. What this means is that those air conditioning systems not only have to work harder but they operate less efficiently when the surrounding air temperature is higher which all adds up to a whole lot more fossil fuels being burned in order to overcome the effects of a bad choice of roofing materials. In Australia I believe it should be illegal to use a dark tile roof on a building.

To quote from the Wikipedia article on Urban Heat Islands, ‘Mitigation of the urban heat island effect can be accomplished through the use of green roofs and the use of lighter-colored surfaces in urban areas, which reflect more sunlight and absorb less heat.’ This is why, for the Greeny Flat we chose to use a light coloured (Shale Grey) Colourbond steel roof. Without going into too much technical detail, this colour has a ‘solar absorptance’ (SA) rating of 0.43 which compares very favourably (lower number is better) with galvanised steel which has an SA of between 0.65 and 0.80 (depending on how weathered it is), or a dark grey tile roof which has an SA of 0.96.

The Wikipedia article also states that, ‘Despite concerns raised about its possible contribution to global warming, comparisons between urban and rural areas show that the urban heat island effects have little influence on global mean temperature trends.’  This suggests that the Heat Island Effect is not contributing to global warming. I disagree because, what the article doesn’t consider is the amount of fossil fuels required to be burned in order to keep the inside of buildings cool in urban areas. Buildings with dark roofs have higher air conditioning loads and urban areas with higher temperatures make air conditioning systems less efficient. Plus, all those air conditioning systems actually expel heat to the outside of those buildings which heats up the surrounding area even more. This all adds up to a huge amount of fossil fuels burned globally to keep buildings cool which certainly contributes greatly to global Co2 levels and climate change.

So, for the benefit of the occupants of a building, the surrounding neighbourhood, and the greater environment, think light colour and light weight for a cooler roof.

And, of course, don’t forget that the roof also needs to be insulated well to stop the heat that is absorbed by the roof from making its way into the interior of the building.

A few days ago my darling sister sent me the following link to an article about the arrival of the Tiny House Movement in Australia.

http://theconversation.com/move-over-mcmansions-the-tiny-house-movement-is-here-32225

I’d known about the Tiny House Movement from my time living in the states. In fact I met a guy from Seattle whose entire house and office measured just 75 square feet (about 7.5 sq m). I never saw it but obviously that’s a bit extreme. The article above states that “tiny houses are generally smaller than 40 sq m” so the Greeny Flat, at 57 sq m doesn’t qualify as a Tiny House, but given that the average new house size in Australia is now 214 sq m, we are pretty small.

The interesting thing for Cintia and I is that this feels like PLENTY of room for the two of us. The image below shows the basic floor plan of the Greeny Flat. We use the bedroom in the NW corner as our “Master” bedroom and the other one as our dressing room. We also keep a futon sofa bed in the SW bedroom so we can use it as a guest bedroom when we have friends to stay. The small alcove to the south of the living room is our office and the rest is pretty self explanatory.

The room layout of the Greeny Flat.

It definitely took as a little while to adjust to the smaller space and we had to decide which possessions to put away in the garage (or give away). But now that we’ve been in here for six months we’re really starting to appreciate the benefits of a small house. Below are a few quotes from the article mentioned above which summarise some of the advantages. And while they’re talking specifically about “Tiny” houses the same holds true for small ones like the Greeny Flat.

Primarily there is the sustainability point… “the major factors that determine a house’s greenhouse gas emissions are its size and location; the bigger and more isolated the house, the larger its emissions“.

“The benefits of tiny houses include overall sustainability, reduced energy and water use (tiny houses are often “off the grid”) and, of course, affordability. Some tiny houses can cost less than A$10,000. Moreover, they use significantly less resources to build, and are often constructed from salvaged materials or sustainably sourced products.“

To this list I would add that a small house is much easier and less expensive to heat and cool; much easier and quicker to clean and maintain; and cosier to live in.

All of which adds up to a “Triple Bottom Line” benefit, i.e. a small house is more affordable, better to live in and better for the planet.