wanting to build a new sustainable home, but builders I have spoken to seem reluctant to embrace sustainable options such as double glazing, PV etc. General response is "these items add major costs to the build". Also need a designer that understands or has the ability to design a house into the side of a slope.
new home
(47 posts) (14 voices)-
Hi Jenleh,
The builders do have a point, high performance windows and PV systems are expensive, but any sensible builder will itemise the pricing so that you can see just how much these 'extras' are. Of course, a house needs windows anyway, so it's always cheaper to get good ones up front than replace ordinary ones with better ones later. Even if the frames can take single glass OR IGUs, what do you do with a bunch of 2nd hand glass?
PV is readily done later, as long as the roof is designed with the appropriate orientation, pitch and area in the first place. It should be a separate item on the price anyway.
I'm doing a project at the moment and I've suggested the PV be on the adjacent shed roof, rather than the light coloured main house roof. The house roof is designed for house performance, and therefore the North half isn't an ideal pitch for PV. The heat of a close coupled PV array would also make a large area of the light coloured roof behave like a dark roof, which is a bit pointless. (There isn't the option of frame mounted panels, because they would block other roof openings.)
On the shed, or better still an open frame, the heat is either not such an issue or simply dissipated, which seems to improve cell performance anyway (going by other threads on here.)
Site slope in any direction is easily worked with, though some have more benefits than others. A North facing slope maximises your Passive Solar options, while a South facing slope and view can mean big energy losses from even good windows on the 'wrong' side.
Bear in mind that the steeper the site the more money gets soaked up getting to floor level. If you can put something under there like garages or another level it reduces 'waste' cost, but the whole industry is being pushed to do more 'universal housing' that suits any occupant - it's all compromise.
Posted Saturday 19 Sep 2009 @ 10:55:37 pm from IP # -
G'day Jenleh,
Sounds like opportunities here to project manage those two aspects of your build yourself. Usually the supplier of double glazing and pv would have no difficulty quoting to do this work. All the builder does is manage a 'list of projects' which ends up being a house.
As for a sloping site, if it's not to steep it presents a real opportunity to avoid slab on gorund , hide rainwater tanks and lots of other goodies. In a hot climate cooling is a lot easier. If you are in an area where there are lots of homes on sloping sites get the builders details from local residents. They may also have some useful feedback, things to watch out for and costings.
Good luck.
Posted Saturday 19 Sep 2009 @ 11:40:36 pm from IP # -
dymonite69
MemberJenleh,
Good on you for wanting to build a water and energy efficient house. Don't think that it has to be expensive or fancy. Many of your gains are almost cost neutral. Correct orientation and shading is a priority. I don't know where you live but getting free sun in to the house during winter means you won't need any heating during the day. Good shading with correctly sized eaves will reduce air temps in summer.
Put your money into good insulation, radiant barriers and weather-sealing to stop unwanted heat entering or escaping the house.
Double glazing during construction can be cost-effective in most temperate climates. Much less so if retrofitting (or in the sub-tropics). Best to do it now. Shop around (including interstate). There is a wide range in prices that does not necessarily correspond with quality.
Greywater recycling is the simplest and most effective way to reduce water consumption is is not dependent on rainfall.
Depending on sun availability and climate, solar HWS will reduce between 50-75% of water heating energy. But in most situations, a heat pump water heater is even more efficient (but are more expensive).
I would not think of PV panels unless you have done all of the above and have money leftover. Personally, I don't think they are cost-effective at current prices. I'd rather buy green energy to reduce my carbon footprint.
Other things like CFLS, water efficient taps, efficient appliances make some difference but not as much as following the above.
The reality volume builders (and trades) have little idea about eco-building. You will need to a do a bit of cajoling and coaxing to achieve your goals. But it is possible. Alternatively find your own building designer and contract the custom design to a small builder.
Posted Saturday 19 Sep 2009 @ 11:46:59 pm from IP # -
franks
MemberIm looking myself to build a small house on my 10 acre block, want to do all the good things in good low energy design good thermal mass, building orientation ect,im finding project builders dont like to use slab floors, zincalune/colorbond cladding, double glazed windows,aircell double foil sarking, its ironic all house need cladding, windowns,sarking and a floor, the price quoted is many thounds extra for my requerments, you would think the price should only be the difference between timeber floor,bearers,stumps, hardieplex cladding and standard windows, standard foil sarking.
Are we getting ripped off or builders are just lazy or set in there ways
Posted Sunday 20 Sep 2009 @ 12:10:28 am from IP # -
norbert
MemberHi jenleh,
After at times stressful 6 months of building,we have just moved into our new home but it was definately worth it.
We have used Polystyrene external cladding R4.5,double glazed PVC windows, frames sealed with spray foam,2.5 kw PV system,low energy light bulbs, apricus 30 glass tubes SWH,7000gal water tank which feeds the entire house but the kitchen sink,R 6 ceiling bats+R2 wall bats,slab for thermal mass,north facing orientiation with floor to ceiling windows and solar pergola for shading,hydronic heating for winter back up(only 7 radiators).
Even though it's winter we generate more electricity then we use and have enough tank water to run the house.Our gas consumption is minimal so far some 4.5 m3 a day.In comparison ducted heating we had at the rental property we lived while were building guzzled through some 17 m3 of gas a day.
Building a sustainable house is not that hard,you need to do your homework and direct the builder down the right path.I'm with you that many builders aren't interested as building different is to them too much of a hazzle and many believe less profitable.But like our builder, there is always someone out there who looks at it as a challenge.In regards to cost,yes having all the features as listed above do cost money.We simply reduced the overall cost by "only" building a 21 square house.Victorian average is around 28 square.Ball park cost figure in Vic is around $ 9-10.000 a square,so that was some $65.000 in savings.
We have maximised living area by cutting out all useless space such as halways etc.We have 3 children + 3 dogs and plenty of room to live a comfortable life.I have to admit if I hadn't insisted to have a pool table in the house, then we could have even build the house some 2 squares smaller.Our cost saving was reduced building size and this enabled us to have all the "extras" which have reduced the running cost of our house to almost zero.
Good luck to you!Posted Sunday 20 Sep 2009 @ 12:25:53 am from IP # -
dymonite69
MemberJenleh,
I would venture to say that you could easily get most houses to a 7.5 star energy rating (one third of the average Oz household) at a 5-10% added cost to the build just by following some simple principles. In most cases this would require off-the-shelf conventional materials and systems.
In eco as in any engineering challenge, things become a law of diminishing returns. You can throw more and more money into it but eventually the incremental benefits become smaller. For instance if you live in Melbourne going from R 2 to R 4 insulation might save you $250/year but then going from R 4 to R6 will save you only an additional $80/yr in heating bills.
Posted Sunday 20 Sep 2009 @ 1:18:13 am from IP # -
dymonite69
MemberFranks,
There is a combination of reasons why builders shun ESD systems.
The industry is set up to produce building at maximal efficiency in terms of cost and speed. Remember that labour contributes up to half of the work done. This can be chewed up trying to procure a new material or attempt a different installation. Hence they work from a very narrow repertoire of materials and construction techniques. Only few like the challenges of something which is bespoke or different. It doesn't just have to be ESD. That is why builders and architects can have a difficult relationship. Your job during the design and project management phase is blending what you want to achieve with what the builder is familiar with. By understanding their issues and speaking their language then you will have greater success in getting your ideas implemented.
Posted Sunday 20 Sep 2009 @ 1:40:23 am from IP # -
There are a couple of points with the above posts.
Jenleh, we still don't know what state you're in, because our profiles aren't working at the moment.
I note that Franks finds local Victorian builders want to do suspended timber floors, whereas in NSW builders almost always want to do slab floors - very odd. It must be just what they are used to.
The cost of different materials should be the last concern of the builder, eg Aircell vs normal reflective sarking, because the builder is getting a percentage markup on all of the material prices anyway. If the windows cost 50% more but are installed in exactly the same way (though a fair bit heavier) you'd think the builder would lap it up - money for nothing.
I use heaps of Colorbond wall cladding, the material is inexpensive and long lasting, BUT, the trim angles used around windows and door frames are VERY expensive and the labour content on 'busy' walls is very high. My usual builder commented that on one project the trim angles added up to the same cost as ALL the Colorbond wall cladding they were used with!! That was a surprise.
In terms of cost efficiency it's best used on walls with fewer openings or difficult access (reduced need for future painting) and use something simple and cost (materials AND labour) effective on the busier walls where all the windows and doors are.Norbert's house sounds like a beauty - he should put some pictures on the ATA page on Facebook for the benefit of everyone.
Posted Monday 21 Sep 2009 @ 2:12:01 am from IP # -
jenleh
MemberThank you all so much for your responses, it is great to have such good feedback. We are building at Bacchus Marsh in Victoria and would prefer to put a slab on the ground 1.because of the advantage of thermal mass, 2. to enable easy access to the external areas (garden). We have 1/2 acre block so have space and no issue with tanks etc being visible. My vision is to build the house into the side of the slope so that that the west wall of the building will be a "retaining" wall. This will also give good thermal mass and protection from the more aggressive westerly weather.
I have considered managing the project myself, but hesitate due to my lack of experience (I have never built a house before). I have certainly done extensive research and reading and know things can be done, but finding the tradesmen seems a daunting task. Norbet sounds like you have a lot of knowledge to share and I too would like to see some pictures and thanks for the tips JohnB. If anyone has some good contacts I would appreciate the tips.Posted Tuesday 22 Sep 2009 @ 10:19:47 pm from IP # -
dymonite69
MemberJenLeh,
Here is a link to the description of our house:
http://forum.homeone.com.au/viewtopic.php?f=20&t=14050&p=169573#p169573
It looks conventional apart from more extensive north facing glazing and its longer W-E axis.
Our heating and coolng energy consumption is 1/5th of our previous residence which was 2/3rds smaller.
In winter when it is sunny the outdoor temp can be 8 degrees and inside will be 21. We switch heating on to keep temp at 21.
Last summer heat wave the temp was mid/high 30s for a week and the house didn't get warm up past 28.
We recycle all our wastewater through a Biolytix system and have tank capacity at 60 kL, we could increase this to 90 kL because of our higher rainfall.
A very useful and detailed guide on building energy efficient is put out by the government is:
http://www.yourhome.gov.au/technical/index.html
Not all of your trades have to be eco-trained but a good way of getting contacts is through a local eco-village in your area which used them.
Posted Tuesday 22 Sep 2009 @ 11:23:57 pm from IP # -
Jenleh,
The recessing of the structure into the hillside is a good idea, and probably what's scaring 'normal' builders.
Hard to understand their resistance, half the garages in the country (probably an exageration) are cut into a slope.
It just needs to be a well designed and well assembled corefilled concrete blockwork wall. Your engineer would detail the structure and the reo in combination with the floor slab structure. Because it's 'ground connected' the R value of the structure isn't a problem. The waterproofing, porous backfilling and drainage are critical of course, but not unusual.
One area to watch is where the wall comes 'out of the ground', because there the lack of R value will become an issue assuming it's below ceiling height. You'll have to detail some sort of cladding and insulation over that area of wall without causing a termite issue.
Posted Tuesday 22 Sep 2009 @ 11:47:00 pm from IP # -
norbert
MemberI've posted some pictures on flickr (link below)
http://www.flickr.com/photos/mopsl/?saved=1
hope it works
Jenleh,we have built in Woodend so not far away from Bacchus Marsh in case you want to have a look.
Posted Wednesday 23 Sep 2009 @ 3:51:20 am from IP # -
dymonite69
MemberPeople have commented positively on it. I think it is an attractive alternative to stone or brick. You get a large profile 'stone' look for about the same price as clay brick per m2 of walling (with much lower embodied energy). We used for a BV construction so we aren't really getting the thermal benefit of it as internal mass. I know people have expressed concerns about moisture control with single skin and thermal bridging through the mortar bed. I don't have first hand knowledge of this issue. Montessori School (Gisborne) in Gipssland had an entire classroom done as single skin. You could speak to the Victorian rep for contact details or just call the school. You may wish to look at that.
I would expect that a single skin Timbercrete wall would have similar thermal properties to an AAC (Hebel) wall. The BCA has recently approved 200mm AAC as a single skin wall that can achieve adequate thermal properties to meet standards for a temperate climates. You probably could also do Timbercrete as reverse brick veneer with the option to boost insulation around it in the cavity.
We had a good mason who laid it nicely and spent time getting the colours right for the mortar to blend in to the blocks. The Timbercrete rep reckoned it was one of the best jobs he has seen with the product. I think this makes a difference between a good looking result and a dodgy one. Technically the blocks are more like stone to lay. It is a bit of challenge to lay square in all dimensions so it is not necessarily going to go up faster because you are using less blocks. Expect some variation in uniformity because of the custom nature of the blocks even with our 'sandstone' ones. I can email you pics if you want.
The only thing I would do different is use a much thinner mortar bed for aesthetics and reduce thermal bridging. Our were made chunky so that the height of the course fitted with door and window heights. I would have altered our window schedule if I had known that. The local manufacturer is quite happy to custom make a mould to your preference. The cost is trivial. Less than $150. We had a custom mould for quoins on the corners. They were made to project out and were a lighter colour to give a fake heritage look. All they do is just add an oxide to the mixture to achieve colour variation. The mason thought it set off the wall nicely - otherwise it have looked a bit boring. The final product was slightly pinker than the sample. Not a big problem but you may want to check the first batch to ensure it is what you expected. Just because you are eco doesn't mean it has to be ugly.
The rep was very helpful with all our requests. He was prepared to stay initially on site and speak to our mason on correct laying procedure. He said it was in his best interest to make sure the product was made to look good. The only thing that slowed things down was that the order took several months to complete and this held up the building process. The company apparently had a large run of orders when we started. This is a hand made product so that aren't stamped out as fast you would expect a brick factory could.
Timbercrete also does a polystyrene insert version but they are much more expensive. They also have a new product which is a thin veneer which is glued on like veneer stonework.
Posted Sunday 27 Sep 2009 @ 9:34:36 am from IP # -
I've drawn many Timbercrete houses, all being single skin using the 200mm 'Cobblestone' blocks.
A bit like mud brick or rammed earth, they seem to work in spite of their R value rather than because of it. The 200mm blocks are listed currently on the Timbercrete website as R1.02, though I thought they were marginally higher at R1.05.
I understand that the styrene cored blocks are R2.3, or were something like that last time I discussed them with our local distributor.
200mm Hebel's R value is higher at R1.4-R1.7 depending upon the material selected, but lower in thermal mass.
Just for comparison, a 'normal' clad house wall with sarking and R1.5 batts is about R2.2, though has next to no thermal mass. A couple of current projects for cool and hot/cold climates will have walls of approximately R4 - with the thermal mass elsewhere.
Posted Sunday 27 Sep 2009 @ 10:48:52 am from IP # -
dymonite69
MemberJohnB,
I would be interested to know the thermal performance of single skin Timbercrete. Have you got first hand reports from the owners? Are their average heating requirements lowered e.g. use less wood, lower energy bills.
I have a theory (unproven but based on anecdote) that you don't need massive insulation or massive thermal mass to be comfortable but just the right combination of both.
Aerated concrete, Timbercrete and log cabins fits this description as a single material that achieves both. Taken in themselves they aren't particularly massive or insulating but have intermediate properties. Used to build houses, they seem to work.
I speculate that single skin or reverse brick veneer AAC will be the future of energy efficient volume building. Cheap, widely available, fast to build and lower embodied energy.
Posted Sunday 27 Sep 2009 @ 11:16:35 am from IP # -
Dymonite69,
I've got a few first hand reports as well as having been inside one local Timbercrete example, with another one here under construction and one due to start later in the year.
(Both of these were drawn a couple of years ago.)When I visited the local clients it was a warm day of about 32 degrees with some wind around, and all of the windows were open, yet inside the temperature was far lower. I was very surprised, expecting that the windows would need to be closed to keep the house cool. Being totally built out of the Timbercrete blocks, all inside walls as well, it seemed to just strip the heat out of the air as it flowed through the house. This would lead to the house slowly warming through the day then cooling through the night, as expected. I guess on a hotter day you just keep the windows closed. The clients report that it's comfortable in Winter, but I don't know how much fire use there is. It's a simple three bedroom passive solar layout, quite conventional.
Certainly the moderate thermal mass/moderate insulation seems to work - in a moderate climate.
My concern would be using this approach in a colder climate. If the orientation is good and Winter sunshine is available (not much good if it's heavily overcast all Winter) this sort of structure may work - but the lower sun angle and colder nights could make it difficult.
I've been in many mudbrick homes in this area in Winter, and they were lovely and cozy, but the fireplace was busy too! Building a bad design out of 'alternative' materials won't make it energy efficient in use. But I've also been in mudbrick homes on the same weekend that didn't have the fire on, and were perfectly comfortable, because they were good designs. (Not mine, by the way)
Once you get a climate where heating is the main concern, I suspect you'd need to tip the balance towards more insulation. There's only so much North glass you can fit in a building for passive gain, and even really good windows are the weak link after dark.
Posted Sunday 27 Sep 2009 @ 11:33:52 pm from IP # -
dymonite69
MemberJohnB,
Your observations are interesting. Many years ago, the OakRidge National Laboratory modeled several variations. Using conventional walling materials they showed than mass inside + insulation outside had the best thermal performance. This was compared to various arrangements. Their conclusions are probably the basis of recommendations for temperate climates today.
Mudbrick and rammed earth have different thermal properties to the others I mentioned. There are very massive but little insulation. Strawbale is the complete opposite.
The ideal 'alternative material' design would be a good passive solar layout with strawbale envelope and rammed earth internal walls. Your heat battery remains inside and your R 9.0 strawbales will stop it leaking out again.
Posted Monday 28 Sep 2009 @ 1:14:27 am from IP # -
Anonymous
UnregisteredWhen you build a new house and you paint it, you want a good primer and then you want two good coats of paint on it. This was build up over the years, so were going to have to remove it, and there are several different ways to do that like mixing paint can lead to disaster inside your house; you want to take care before you start painting to make sure you do the job right. That means prepping the house completely before you paint. That also means choosing the right paint to give you the look and the durability you want.
for more info : http://www.solar-cool.com.au/
Posted Friday 26 Mar 2010 @ 9:59:44 am from IP # -
From what i understand it shouldn't cost much more to build a home with eco-friendly principles. You need to make sure that your builder is a greensmart builder, and they can ensure that they meet govt legislation and give you a high energy rating.
Check out this link http://www.paultalkingbusiness.com/node/12
This is an interview with a designer who specialises in energy efficiency and he talks about your issue, hope it helps
Posted Monday 12 Apr 2010 @ 9:00:38 am from IP # -
dymonite69
MemberOn the surface it would seem that an Accredited Greensmart builder will help. We went with a building company whose owner actually collaborated with an eco-architect to build his house. Having said that I felt I got marginal advantage in the design and construct phase. I knew more about the issues, the modeling and the options than anyone else.
The principles are fairly straightforward. Most of the gains will come from good design. It is fairly easy to identify major problems just looking at some plans and elevations. Additional local weather information helps tweak the design further. There are some aspects of construction detailing which are important but the errors are easily identified e.g. gaps in vapour barriers and insulation, poor weathersealing and weatherization. All of these things you can oversee yourself in conjunction with discussions with the site supervisor.
Posted Monday 12 Apr 2010 @ 10:42:51 am from IP # -
PeterReefman
MemberAs a residential builder who's extremely committed to sustainable building (and also building local community resilience through a "Transition Towns" philosophy) I'll try to give you an opinion from the other side of the fence. Before I do please understand that I'm not posting this as a cheap advertisement.
Just as it is very hard for people to find sustainable builders in their region, it is also very hard for the 'green' builders (rather than the greenwash builders) out there to find decent clients within a reasonable travelling distance from their base.
Because of my background I do get people who start out wanting a cutting edge zero carbon sustainable home, but invariably (meaning every single time unfortunately), by the time they've gotten through the design stage they've watered it down to an almost unrecognisable level. It's frustrating and disheartening.
Having said that, I have had one chance to do a really sustainable house. I did find a client who was happy to do things properly and push those boundaries. The house ended up being thermally 8-Star with a heating/cooling bill of about $20 a year, and a 1.4kw PV system made it operationally carbon zero, with enough energy surplus to eventually (within about 60 years, or less if/when the PV system gets expanded) make the embodied energy of the construction zero carbon and then negative as well. Good. But that client needed to be me. It was clear that it would never have happened otherwise.
The plan was that it may inspire others to do it, whether I built them or not. I've had hundreds of people through, but not one person has come forward in terms of actually building.
All the best with finding a good builder for your house. By the way I've done a house which backed into a hillside with the required concrete filled blocks, waterproofing, etc. Everything went really well but it was still by FAR the most expensive wall I've ever built, and even though it's a wonderfully cool room in the summer, the cost would've been more effectively spent on better insulation everywhere else, or better curtains, or an active solar system, etc.
Posted Monday 12 Apr 2010 @ 1:42:37 pm from IP #
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