Did you know that Australians have the biggest erections in the world?
I’m talking, or course, about the size of our new homes.
When they say ‘acreage design’ I think they’re talking about the floor area but if you read the fine print, the good news is that ‘the layout ensures energy efficiency and environmentally sustainable living’…. hmmm, I’m going to call ‘Bullshit!’ on that one.
I’ve written about this before but was reminded again by this recent article from The Conversation just how crazy this is in a country that also has some of the least affordable housing in the world. The following quotes from the article help to illustrate the point.
Over the past 60 years Australian homes have more than doubled in size, going from an average of around 100 square metres in 1950 to about 240 square metres today. This makes them the largest in the world, ahead of Canada and the United States.
At the same time, the average number of people living in each household has been declining. This means that the average floor area per person has skyrocketed from 30 square metres to around 87 square metres.
Results show that larger houses use much more energy, but also that as size increases, the energy used in building and maintaining the house grows by more than the energy used to operate the house.
It’s important to note that the cost of homes as well as the amount of energy they use is typically measured in terms of $/sqm or kWh/sqm. This has the effect of making large houses seem cheaper and more energy efficient because you are dividing the cost and the energy use by a larger number of square metres. It is much more useful and realistic to think about the cost per person or the energy use per person. The following chart from The Conversation article does just that and compares the total energy use over 50 years PER PERSON for different sized houses with different numbers of people living in them. Note that the biggest house uses more that twice as much energy PER PERSON than the smallest house (also note that the smallest house listed is nearly twice the size of the Greeny Flat which we find to be perfectly adequate for two people at 57sqm).
Smaller dwellings tread more lightly on the planet and on your pocket.
The Australian 6-star standard does include house size when considering heating and cooling, but other certifications don’t. Under these other certifications (including the BASIX system used in NSW), a larger house would therefore be easier to certify, considering everything else is constant.
This is ironic since larger houses use significantly more resources, both for construction and operation.
We need to revise current energy efficiency regulations to include embodied energy and other measures of energy if we are to reduce the total energy and broader resource demands associated with buildings.
I absolutely agree that we need stronger regulations. BASIX, which stands for Building Sustainability Index, is a total failure and the proof can be found in the fact that the house pictured in the advertisement, which is enormous and totally inappropriate to our climate with its brick veneer walls, single-glazed windows and black roof, can pass BASIX and is allowed to be built.
Unfortunately, whenever anyone tries to suggest higher energy efficiency standards, the big players in the housing development industry (who have a lot of political influence) jump up and down and scream bloody murder about how higher standards will drive up the cost of housing and make it even more unaffordable.
Well I have a very simple answer for them…. BUILD SMALLER HOUSES!
We’ve had our Mitsubishi Outlander Plug-In Hybrid Electric Vehicle (PHEV) for over a year now and we absolutely love it. We charge it up from our solar panels during the day and do most of our local driving powered by our own renewable energy. We’ve taken it on lots of camping and surfing trips, slept in it, pulled boats with it, hauled building materials and trailers with it… in short it has done everything we’ve asked of it comfortably, quietly, efficiently and economically. We reckon it should be the most popular SUV on the Australian market and yet, hardly anyone even knows it exists. I put that down to an abject failure on the part of Mitsubishi to effectively market a car that would sell itself if people knew about it.
Anyway…. we love it!
So it was nice to read this article from New Atlas which cites a Lifecycle Assessment study comparing a Mercedes E350e (PHEV) to the standard, petrol engine E350. Here’s a quote…
‘According to the lifecycle analysis conducted by TÜV, building, owning and recycling the new E350e emits around 44 percent less C02 than the outgoing E350 CGI, which offered similar performance to the new hybrid, but ran with a conventional petrol engine instead. The testing assumes the car has been charged using a conventional European plug, but also says using renewable energy to charge the battery could improve that figure to 63 percent over the course of 250,000 km.’
Since we primarily charge our Outlander PHEV using our own renewable energy, it looks like our we should see something like a 50-60% reduction in GHG emissions over the life of the car. So not only is it perfect for our needs, it’s significantly better for the planet.
I have an idea for a gadget that I think every home could benefit from and that could also help provide valuable data to research organisations like the CSIRO.
Will Sydney beat the heat record tomorrow?
Right now Sydney is bracing for what is predicted to be the hottest February day on record. Meanwhile we, like every generation before us, live in a house with no air-conditioning. Luckily the Greeny Flat has a number of significant advantages over most of the houses those previous generations grew up in. We have the benefit of understanding Passive Solar Design and how it works to keep a house cool in summer as well as warm in winter. We have an excellent site that is well protected from hot westerly winds and from the late afternoon sun. The Greeny Flat is correctly orientated to allow our roof overhang to shade the north wall and to minimise the amount of wall area exposed to the hot sun from the west. Our windows are also carefully placed to reduce heat gain from the afternoon sun and all our windows have insulating blinds to help keep heat out during the day. The Greeny Flat is clad in a light-weight material that cools down quickly once the sun is off it. It is properly air-sealed and insulated and has sufficient thermal mass to absorb any excess heat during the day and is designed for good cross-ventilation to cool it down at night. And, most importantly, we understand how to operate the Greeny Flat in such a way as to get the best performance from all of the above features.
This is a key point because even the very best Passive Solar house can be too hot in summer and too cold in winter if it is not operated correctly. In the future this will probably be taken care of by automatic devices that do things like open and close windows and blinds at the appropriate time. These things already exist however we are not that advanced. We are still living by the old adage… ‘Passive House, Active Owner’. This means there are certain things we need to do to keep our home as comfortable as possible and reduce our energy use and running costs.
In summer we have to open the house at night to encourage cross ventilation and to cool down the thermal mass and then close all the windows and blinds during the day to keep the heat out and the cool in. The trick is knowing when to open and close the house. To help us with that decision we are constantly referring to two things, one is an online weather forecast (this allows us to know in advance if extreme weather is coming so we can be prepared)
What’s the weather going to do for the next few days?… VERY hot but relief is in sight.
and the other is our own weather monitoring station and in particular the readings for the current indoor and outdoor temperature.
Our weather monitor is currently showing the hottest indoor temp we’ve had at 29.2C (and tomorrow is predicted to be even hotter!)
If the weather forecast tells us that it’s going to be a hot day we start watching the temperature readings early in the morning and the MOMENT the outdoor temperature climbs higher than the indoor temperature we close the windows and doors, draw the blinds and turn off any exhaust fans (because when you blow cool air out of a house you also suck hot air in from outside). In the evening we do the opposite, we watch the weather monitor and as soon as it’s cooler outside than inside we open all the doors and windows to start cooling the house back down.
In winter we keep the windows and doors closed all the time and just open the blinds when the sun is shining and close them when it isn’t. But we watch the indoor humidity level closely because this tells us when we need to run our ventilation system in order to reduce humidity and maintain good indoor air quality. In spring and autumn we keep an eye on the temperatures. If the house feels cold and it’s warmer outside, we’ll open it up and vice versa. So you can see that we refer to our weather monitor every day of the year (and many times a day) to help us decide how best to operate the house.
The other screen we constantly refer to is our energy monitor. This tells us when we have excess solar power and helps us decide when to run appliances or do things like plug in our electric car. (Unfortunately the UK company that made the ‘Wattson Meter’ has gone out of business but there are other good options like ‘Efergy‘ and ‘Smappee‘)
The display for our energy monitor sits right above the stove in the kitchen.
So my idea is for a home monitoring system that combines all of the above. In other words it will display the weather forecast plus the current indoor and outdoor temperature/humidity plus the current energy usage and production. This is the vital information that everyone needs in order to be able to operate their home in the most sensible and efficient way possible. In fact I think it should be mandatory for every home to have this information displayed in a prominent location where it can be seen at all times. It might look something like this only attractively designed.
The gadget that every home needs!
To further assist homeowners with the efficient running of their house it could be programmed to speak to them and tell them things like, ‘The outdoor temperature just dropped below the indoor temperature, this would be a good time to open up the house and let it cool down’, or ‘Your solar system is making a lot of extra energy right now, this would be a great time to plug in the car’. Of course, in the future this gadget might connect directly to automatic windows and blinds, plus all the appliances in the house, plus the car charger, etc and tell them to operate themselves. But for now it could give helpful advice. It could also be programmed to learn about the particular home and the habits of the residents in order to offer the most useful advice. And now and then it might offer some random piece of wisdom like, ‘Did you know that hanging clothes on the line rather than putting them in the dryer could save you $127 a year?‘. I’m sure you get the idea.
The final benefit of this gadget is that, since it would need to be connected to the internet in order to display the latest weather forecast, it could also send a constant stream of useful data on your home’s energy use/production and the indoor and outdoor climate conditions to a trusted research organisation such as Australia’s CSIRO. If enough homes had this gadget installed it would provide a wealth of information about the way people use their homes, how comfortable they are and how improvements to the home can affect occupant comfort and running costs.
I plan to pitch this idea to the CSIRO as well as to companies that already produce energy monitoring equipment. If anyone reading this has any thoughts about who I should contact or ways I could improve the idea, I’d love to hear from you. Meanwhile, at the very least, get yourself a cheap indoor/outdoor temperature and humidity monitor (I think Bunnings sells them for about twenty bucks) and an energy monitor. I think you’ll find them very useful and helpful.
(p.s. Please note that our strategy of closing the house completely during summer days and opening it up at night works well because our house, and in particular our roof, is very well insulated. In a home with poor ceiling insulation or an unventilated attic it is quite possible that closing the house during the day might cause it to get unbearably hot by late afternoon. Also, different climates require different strategies… what works for us here in the Southern Highlands of NSW might not work at all for someone living in Brisbane for example. You have to figure out how to operate your own house in the best way to suit your climate, your site and your lifestyle. I just hope it involves more than just turning on the air-conditioner.)
This week we present Episode 11 in our series of short videos about the energy retrofit of the old fibro cottage next to the Greeny Flat. In Episode 10 we explained the reasons why we are turning the whole north wall of the cottage into a Solar Air Heater. In today’s episode we show how.
This completes Stage 1 of the retrofit so we’ll be leaving the videos for the moment and will return with more when we are ready to start on Stage 2.
Energy Performance and Resale Value
In our Newsletter on January 13th I wrote about an excellent website called liveability.com.au which is aiming to move sustainability and energy efficiency into the mainstream of Australian building and housing development by training real estate agents to recognise and value features like Passive Solar Design and Renewable Energy Systems. In turn, real estate agents will educate home buyers and sellers about the potential for increasing resale value by making energy upgrades to homes that will also reduce running costs and improve occupant comfort.
The beauty of this approach is that, if people can see that it is in their own best interest to make changes to their homes that will reduce running costs, improve comfort and increase resale value, they are much more likely to do those things that also happen to reduce fossil fuel use and greenhouse gas emissions… even if that’s not their intention.
Along those lines I was encouraged this week to see these two articles from the Energy Matters Newsletter that point to solar power and energy efficiency being factors that can improve home values. As noted in the first of the following two articles…
After a bit of a break over the holiday season we’re back in action on the Energy Retrofit of the old fibro cottage next to the Greeny Flat. This week we present the tenth in our series of short videos about the project. In our last episode we showed how we converted the old brick chimney into a small Trombe Wall to help store some solar heat in winter. In this week’s episode we explain why we are making the entire north wall of the cottage into a solar air heating panel.
To summarise, it’s a way to compensate for a lack of north-facing glass (please remember we’re in the Southern Hemisphere so everything is turned around for our Northern Hemisphere readers who should be thinking of it as south-facing glass) and to bring in plenty of pre-heated fresh air to maintain good indoor air quality in winter.
Thanks for watching. In our next episode we will demonstrate the details of how we put the whole thing together.
Hello again, I’m still working out the details of the Solar Air Heating Wall for the cottage retrofit so no video this week. Instead I’d like to share a couple of interesting developments which have just come to my notice in the last couple of days.
liveability.com.au Aims to Convert Agents of Real Estate into Agents of Change
Yesterday I was invited to a meeting (and delicious dinner) with Cecille Weldon, creator of the website liveability.com.au. On an interesting side note, it turns out that I had met her once before, thirty years ago at her brother’s 21st Birthday Party. One of my friends from architecture school was dating her brother Harold at the time and a group of us were invited up to the Hunter Valley for an ‘Out of Africa’ themed party which included joy rides in his father’s Tiger Moth bi-plane. I vividly remember my turn in the plane as well as one of the funnest parties I’ve ever been to… but that’s another story.
Here’s a photo from Harold’s Birthday Party… that’s me on the right.
What Cecille is doing at liveability.com.au is far more relevant to our work here at the Greeny Flat. She started the website while working for a national real estate agency and it has recently been taken over by the CSIRO. That in itself is remarkable. The CSIRO is in the business of developing technology and selling it to others to commercialise, not the other way around. The fact that they’ve bought it shows that the CSIRO must see enormous potential for this program to bring about positive change.
Briefly, what liveability.com.au aims to do is to convert real estate agents into agents of change for the better. The issue it is attempting to address is the fact that the real estate industry does not currently attribute fair value to the sustainability features of a home that is listed for sale. Now, you won’t find the word ‘sustainability’ anywhere on Cecille’s website because research shows that terms like ‘energy efficiency’ and ‘sustainability’ have been so bastardised and over-used that they actively turn people off. So Cecille talks in terms of ‘reducing running costs’ and ‘improving comfort’. Those are benefits that everyone wants and can agree on, regardless of their political or environmental leanings (I guess this means I’m stuffed because my whole website is riddled with ‘sustainability’s and ‘energy efficiency’s… oh well).
The problem is that, because the real estate industry doesn’t value sustainability, the money that people spend doing things like adding insulation, replacing windows or installing solar power systems is often not reflected in the price of the home when it comes time to sell. This has the effect of discouraging many homeowners (particularly property investors) from investing money in those features that do improve the comfort, reduce the running costs and improve the environmental, social and financial returns on their investment. Instead they tend to focus on granite counter tops, fancy bathrooms, and the other cosmetic improvements that the real estate industry tells them will ‘improve the resale value of their property’.
So liveability.com.au was designed to train real estate agents how to recognise ‘The 17 Things’ that are most important in improving the environmental and energy performance of a home. Cecille has done a major amount of research to identify these ’17 Things’ that everyone can agree on. It’s not a comprehensive list of sustainability improvements by any means but it’s a great place to start to get agents, buyers and sellers to value these features. Here’a screen shot from the website with the basic list of ‘The 17 Things’.
As an advocate for the advantages of Passive Solar Design, I am very pleased to see that ‘The 17 Things’ include many of my own list of 10 Simple Steps to Passive Solar Design. It also encourages people to consider the Climate Zone in which the house is located and the advantages of ‘Living Locally‘, which is described as
‘Living close to a vibrant community with local produce, community gardens, well maintained bikeways and walkways helps reduce the costs of transport and is great for your health too!’
The reason all of this might be important to you, dear reader, is that the CSIRO has BIG plans for liveability.com.au. In fact within the next four years, ‘The 17 Things’ could become the standard for how homes are assessed at the point of sale. This means that the money you might have already spent or might be thinking about spending on any of ‘The 17 Things’ has a very good chance of paying you back in terms of increased market value when you go to sell.
When you think about it, it’s quite brilliant because real estate agents really are the ‘middle man’ (or woman) between developers/builders/investors/sellers on the one hand and home buyers/renters on the other. By tapping into a common desire for ‘improved comfort and reduced running costs’, liveability.com.au may turn out to be a major agent of change itself and really help to move sustainability into the mainstream of Australian home design and construction. As Cecille would tell you, it’s all about the way we communicate and I wish her the very best of luck.
New ‘Green’ Brewery Opens Today in Mittagong
On the subject of ‘Living Locally’, Cintia and I just got back from a brief visit to our new, local, ‘Green’ brewery. Started by a young couple, Deb from Oz and Jacob from Texas, Eden Brewery has just opened it’s doors today. So, in the purely altruistic spirit of supporting a local business, we thought we’d better go along for a taste. And I have to say, the beer is delicious. In fact my good friend Miles (who has been known to brew a few himself and has sampled ales all over the world) took a few sips, sat back and declared, ‘I’ve died and gone to heaven’.
Miles, Cintia and yours truly in beer heaven at Eden Brewery
Eden has six beers on tap right now ranging from a refreshing, summery ‘Birch Wit’ to a dark and robust ‘Ebony Porter’. Cintia liked the Wit, I especially enjoyed the ‘Australian Palm Pale’ and Miles was last seen heading back to Eden with another mate in search of more of the ‘Giant Redwood Imperial IPA’. The fact is though, that all three of us enjoyed all six of their delicious brews. As Miles put it ‘I can’t disagree with any of them’.
Apart from the excellent beer, Eden Brewery is also doing their best to be a positive agent for change too. Not only do they brew their beer using 100% Green Power, they are also committed to donating 10% of their profits to Oxfam with the goal of bringing clean drinking water to people who don’t have any.
I wish Deb and Jacob the very best with their endeavour and I encourage you to drop by the next time you’re in Mittagong. They’re open 11am-8pm, Wednesday to Sunday at 1/19 Cavendish St, Mittagong. So…do youself, the community, the planet and your taste buds a favour and try a cold one at Eden Brewery.
Happy New Year everyone! I hope you all had a relaxing break. Cintia and I had an amazing four days PHEV-camping down near Ulladulla which included getting soaked in the best thunderstorm I’ve seen for years; a night out on a boat on a lake under a spectacular moonless, starry sky; a ruined trailer tyre with no spare; some fun surfing, sailing and snorkelling; and a wonderful day spent photographing patterns in the rocks and sand as well as some gorgeous starfish in the rock pools.
Kindred Spirits – star fish in a rock pool with a glass pendant by Absaroka Glass.
The man-made object in there with them is a glass pendant made by my very talented son, Sam, in Montana. If you’re interested in his work you can see lots more of it on Instagram at Absaroka Glass.
Home Energy Retrofit Progress
Over Christmas we took a bit of a break from the renovations of the old cottage next to the Greeny Flat but we’re starting to get back into it now. In our last Newsletter before Christmas we presented Episode 9 in our series of little videos about the energy retrofit process. In that episode I explained what a Trombe Wall is and how we are using the old brick chimney in the cottage to create one. In our next couple of episodes I’ll be showing how we transform the entire north wall of the cottage into a solar air heating panel to help warm the house and provide fresh air in winter. If you’d like to do a bit of homework in the meantime you might want to review a couple of previous Newsletter from May 2015 in which we describe the solar air heater prototype we built as an experiment on the Greeny Flat.
The solar air heater was blowing 42degC air into the house on a 13degC day!
This experiment has proven to be so successful that we are planning to make the panel (pictured above) a permanent fixture on the Greeny Flat and properly duct the air through to the back bedroom. But on the cottage we’re planning to go a few steps further and turn the whole north wall into an air heater. We’ll do this be creating a space behind the corrugated iron on the north wall, collecting the warm air from this space and ducting it right through the attic to the three bedrooms on the south side of the cottage. This will not only help to warm these rooms that don’t get any sun, it will also bring in plenty of fresh air to help control humidity and maintain good indoor air quality in winter. We’ll get into the details of how we do this over the next few weeks so stay tuned.
We’re All Paying the Price for Australia’s Poor Quality Homes
Last week a few readers sent me links to an excellent article from ABC News about one of my pet subjects, namely the fact that Australian building standards are really poor, especially regarding energy efficiency. We all end up paying the price for this through higher electricity charges and the very high cost of having to go back and try to retrofit our existing homes up to a decent energy performance standard.
(Photo from the ABC News article about poor building standards in Australia)
I particularly appreciated this email from Theo. I welcome all reader contributions and feedback. Thanks, Theo, for a great message.
Hi Andy,
I thought of the Greeny Flat when I saw this opinion piece on the ABC news website.
## Why bad housing design pumps up prices for everyone ##
I ponder on how much carbon dioxide one person is responsible for today compared to one hundred years ago. In my working life I may have driven a couple of million kilometres by car, generating much much more CO2 than my forebears. I now choose to not own a car. The car is a health hazard (as well as a wealth hazard) in that you don’t get enough exercise, quite apart from being a health hazard to the planet.
We all need to reassess our basic human needs, and recognise the difference between desires and needs.
I don’t have PV panels at present. My electricity usage over the last four years has been 4 to 5 kwh per day. My most recent bill was my best at 2.4 kwh per day. My water usage is 100 to 200 litres per day. I don’t want a medal, I just want everyone to think about how to use less!
Happy Summer Solstice everyone! It was a big day this week for Pagans and Passive Solar Designers everywhere as the sun hit its highest point in the sky. The sad news for those of us in the Southern Hemisphere is that, from now on the days start to get shorter and shorter…. Winter is Coming! Of course, for those north of the equator it was much more a reason to celebrate as the sun hit its lowest point and now the days start to get longer and sunnier. It’s no accident that just about every major religion originating in the Northern Hemisphere has a significant celebration around this time of year. Having lived in Montana for twenty years where the winters are brutally cold and horribly long, I can vouch for the fact that the Winter Solstice is cause for celebration. This is part of the reason why Christmas in Australia is such an anomaly… it is, by nature, a winter festival so it all seems a bit out of place here in the middle of summer. Right now thousands of families are donning swim suits, hats and sunscreen, jumping in the car with the a/c on full blast and trotting off to a blazing hot beach happily singing, “Dashing through the snow on a one-horse open sleigh”, “Frosty the Snowman”, “Walking in a Winter Wonderland” and “I’m Dreaming of a White Christmas”. On the way they might stop in at the local shopping mall where some poor, portly fellow is dressed up as Santa with lots of padding around the middle, a heavy red coat, and a thick, white beard; shouting Ho-Ho-Ho at the hot-and-bothered last-second shoppers and sweating like a pig on a spit. Meanwhile, back at home, the Christmas Tree (a plantation grown pine which doesn’t belong in Australia) is blazing away covered in snow flakes and icicles.
It is all so wonderfully incongruous…. I love it!
Meanwhile, we continue to plug away at the energy retrofit of the old fibro cottage next to the Greeny Flat. In last week’s video I mentioned some of the complications that can arise when trying to apply Passive Solar Design to an existing building. In this week’s episode I focus on just one of these issues, i.e. the lack of Thermal Mass in an old, timber-framed building, and how we are using the existing chimney to create a small Trombe Wall to take advantage of the only bit of Thermal Mass in the building.
I’ve made two versions of this week’s video. For those who like it quick and nasty, without too much detail, here is the short version. In order not to bore you to tears I have left out much of the detailed explanation of how Passive Solar Design works, why Thermal Mass is important and why it is lacking in the old cottage. For this short one I just focus on what is a Trombe Wall and how are we making one.
For those of you who have had their fill of Christmas Carols and have nothing better to do on your holiday, here is the full version with a much more detailed explanation (it’s about ten minutes long).
Thanks for your continued interest in, and support for, the work we’re doing here at the Greeny Flat. Best wishes for the holiday season. When we return we will look at another trick we’re planning to use to boost the Passive Solar performance of the old cottage.
In last week’s YouTube Episode about the Energy Retrofit of the old cottage next to the Greeny Flat we were making our way around to the North wall of the house where replacing the windows and installing the new cladding is getting a bit more complicated. For one thing, in this part of the building we are not simply replacing the old, single-glazed windows with double-glazed ones of the same size. We are actually changing the size of the windows and adding a couple of new ones in order to try to get more glazing on the north wall of the house. What we are really trying to do is to take maximum advantage of the Passive Solar Design potential of the existing building.
Passive Solar Design is the key to creating a home that stays warm in winter and cool in summer with minimal additional heating or cooling. So in this week’s Episode we take a step back and talk about how Passive Solar Design works, how it can be applied to an existing building and some of the challenges we face when we’re working with existing conditions and council regulations that are less than perfect for optimum Passive Solar.
I’m excited about the next phase of this retrofit project because, as I mention in the video above, we’re getting into some uncharted and innovative territory. I’ve been reading about Trombe Walls for decades but I’ve never actually built one (below is another YouTube video that explains in more detail what a Trombe Wall is) and the concept of using the entire north wall as a solar air heater is a fairly new idea that we’re trying to figure out as we go along. Long time readers will know that I’ve done some experiments with a solar air heating panel attached to the Greeny Flat (you can read about this in previous Newsletters here and here). This has proven to be highly successful so we’re planning to make this a permanent fixture on the Greeny Flat as well as applying the lessons we’ve learned to make a bigger version out of the entire north wall of the cottage. Stay tuned to our Home Energy Retrofit Videos to see how this turns out.
Are We Really Saving the Planet?
Meanwhile, here is an excellent article forwarded to me by my Uncle Simon in Melbourne. This is a sobering reminder that what we like to call ‘Sustainable’ and ‘Renewable’ usually are not truly sustainable or renewable and actually may be doing more harm than good to the planet we claim to be trying to save.
We’re getting close to Christmas and making slow but steady progress on the energy retrofit of the old fibro cottage next to the Greeny Flat. We were slowed down for a while by some tricky flashing and cladding details around the front porch and the curved wall next to it (see Episode 6 here). Plus I’m involved in three different Community Renewable Energy projects in our area which require some of my time and attention. But we’re pressing on with replacing the windows in the last two walls and hoping that we can get the cladding finished before the end of the year.
In Episode 7 of our series of short videos about the project you can see how this process is quite a bit more complicated than the earlier window replacements where we simply fitted the new window into the old opening (see Episode 5).
The good news is we’ve only got three windows left to put in but we’re into the tricky ones where we’re not just replacing the old window with one of the same size. On the north and west walls we’re changing the size of most of the windows and adding some new ones that weren’t there before. We’re trying to move the house closer to the ideal window arrangement for Passive Solar Design (you can read all about that here) which means reducing the amount of glazing on the west side and increasing the amount that faces north.
Due to council restrictions relating to heritage conservation we weren’t able to add quite as much glass on the north side as we would have liked. Instead we’re doing a couple of innovative things with the north wall including placing a window directly in front of the old brick chimney to create a mini Trombe Wall for winter heat storage, and using the entire clad portion of the north wall as a solar air heater. I’ll get into this in more detail in the coming weeks. For now it’s reassuring to note that the sun does not contact the north wall during the day in summer because the house has the correct amount of eave overhang. This means that our solar air heater plan for the north wall in winter will not overheat in the summer.
The north wall of the cottage at solar noon (1pm during daylight savings time) on the 1st of December. Note how the roof overhang is shading the whole north wall in summer. In winter this wall will be in full sun and we’ll be able to collect the hot air from behind the cladding and pipe it into the house. This will help heat the house as well as providing fresh air in the winter when the windows and doors are kept closed.
Thanks for your interest in the project. We’ll continue to provide more details about the Trombe Wall and Solar Air Heater concepts as we progress over the coming weeks.
