Browse Forums Eco Living 1 Nov 19, 2008 1:58 pm So we went to chat to our local GJGardner builder today and liked what we saw in terms of flexibility and quality.
However their price for what we want in terms of floor plan is right at our limit. The lady we spoke to is sceptical of the value of spending more money on energy efficiency features. Their standard offering is CSR R2.0 walls, R4.0 ceiling under colourbond roof, enviroseal wall wrap and 450 mm eaves. We have chosen/created a floor plan that has very good northern window exposure to tiled living areas and minimal windows on other sides. This is a cool temperate climate, in Kilmore VIC. My question is, do those insulation levels sound reasonable and where would any additional money be best spent? I asked about double glazing but the lady's strongly felt opinion was that this was unnecessary given the fact that the Dowell windows they used were already thermally improved. Does anyone know anything about those windows? She said they'd only ever needed to double glaze one house they built, because it had all south facing living areas. Still, by "need" i guess she means to minimally meet 5 star rating, when I would like better. (I asked about that but we got sidetracked talking about an excellent deal they are offering on grid-connected PV systems.) What about roof sarking? I thought radiative gain would be most important for the ceiling, not the roof, especially with colourbond? OTOH we are in a heating climate not a cooling climate and I would have thought radiative heat loss wasn't much of an issue compared to conductive. (Given the low temperature of the house compared to that of the Sun as in solar radiative heat gain.) In summary as you can see I'm fairly confused. Seeing as they get every house independently rated anyway, couldn't I ask them to get the rater to suggest alterations to get it to a specified level, say 7 or 8 stars? Re: Questions... 2Nov 19, 2008 6:50 pm russell Their standard offering is CSR R2.0 walls, R4.0 ceiling under colourbond roof, enviroseal wall wrap and 450 mm eaves. This is a cool temperate climate, in Kilmore VIC. My question is, do those insulation levels sound reasonable and where would any additional money be best spent? R 4.0 ceiling and R2.0 wall sounds about right for your locale. Recommendations for your cold temperate climate can be found at: http://www.yourhome.gov.au/technical/fs47.html The extra building components pushes the R value maybe up another 0.5. You can go higher but its a law of diminishing returns. It's hard to find R 2.5 batts to fit a 90mm stud wall. There are R 4.5 batts otherwise you just can just double up. A little extra money should be spend on good window and door seals (or good window frames Air leaks can cause a lot of heat loss. Insulation is not just confined to the building. It can go around hot water pipes R 1.0 minimum and heating/cooling ducts. russell I asked about double glazing but the lady's strongly felt opinion was that this was unnecessary given the fact that the Dowell windows they used were already thermally improved. Here is the WERS data for Dowell. http://werssearch.freehostia.com/tables ... rer=DOWELL You may wish to compare with other manufacturers but their single glazed U-value is typical of the usual offering. You have several options with window loss. Go with good quality WERS rated double glazing (at least living areas if you can't afford more). Add insulative curtains. Honeycomb/Cellular blinds are an alternative for a more sleek modern look. Or do both. russell What about roof sarking? I thought radiative gain would be most important for the ceiling, not the roof, especially with colourbond? OTOH we are in a heating climate not a cooling climate and I would have thought radiative heat loss wasn't much of an issue compared to conductive. Most colourbond colours are poor radiant barriers - white or light colours are best. Suprisingly Zincalume doesn't fair that much better. Otherwise you need to go with a heat reflective paint. The radiant barrier goes just under the roof with an air gap. If it is on the ceiling shiny side up it will collect dust and lose its effectiveness. As you rightly point out winter heat loss is mainly convective rather than radiative. Foil's main role is in summer. russell couldn't I ask them to get the rater to suggest alterations to get it to a specified level, say 7 or 8 stars? You most certainly can. It's actually quite hard to reach 7-8 stars as you will find. Re: Questions... 3Nov 19, 2008 7:30 pm russell I asked about double glazing but the lady's strongly felt opinion was that this was unnecessary given the fact that the Dowell windows they used were already thermally improved. Does anyone know anything about those windows? Every window in WERS is Thermally Improved - it means a U value better than 8 - which is a miserable level of performance. It does not compare in any way to double glazing... which at worst should be well below 4 (ours is 3.5 and 2.7 with Low-E) russell In summary as you can see I'm fairly confused. Seeing as they get every house independently rated anyway, couldn't I ask them to get the rater to suggest alterations to get it to a specified level, say 7 or 8 stars? The Burbank Future range house is 7-8 stars in every orientation, it is double glazed as you know... "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: Questions... 4Nov 19, 2008 8:15 pm EcoClassic The Burbank Future range house is 7-8 stars in every orientation, it is double glazed as you know... Yeah, trouble is our floor plan wants have drifted well away from any of the Future range offerings and unlike GJG we can't just chop the plan into 15 scraps and reassemble them as we please . Plus we are seduced by the higher quality fittings and, most likely, workmanship of the local GJG. And in fact when you add $5k each for eaves and colourbond to the Burbank price, it isn't much different, even though the Burbank is slightly smaller. Still, add the double glazing to the GJG and back up it goes... Re: Questions... 5Nov 19, 2008 11:05 pm russell EcoClassic The Burbank Future range house is 7-8 stars in every orientation, it is double glazed as you know... Yeah, trouble is our floor plan wants have drifted well away from any of the Future range offerings and unlike GJG we can't just chop the plan into 15 scraps and reassemble them as we please . Plus we are seduced by the higher quality fittings and, most likely, workmanship of the local GJG. And in fact when you add $5k each for eaves and colourbond to the Burbank price, it isn't much different, even though the Burbank is slightly smaller. Still, add the double glazing to the GJG and back up it goes... Burbank has other designs coming through... try the Forrester. "ECOECO" At 'EcoEco', we design windows, we design the best windows, we do it for you, so that when you’re happy we are happy. Tel. 1800 326 326 Re: Questions... 7Nov 23, 2008 4:31 pm russell couldn't I ask them to get the rater to suggest alterations to get it to a specified level, say 7 or 8 stars? I was reviewing our AccuRate report. Each star increments represents a 30% reduction in heating/cooling requirements on the previous star rating. For instance to get from 1 to 10 stars you need to find a nine separate intervention that each reduce the heating/cooling load by almost a third. The average household sits around 1 to 3 stars. The superinsulated highly technical Passihaus system can achieve 10 stars or higher. It consumes less than a tenth of the energy consumption of a standard Australian dwelling. You can jump from 1 to 5 stars fairly easily and without too much investment. To get from 5 to 10 stairs gets progressively more difficult and costly. The Passivhaus system requires a whole set of refined construction techniques e.g. extremely airtight construction with careful engineering and sealing of joints and penetrations at every stage, 30-45mm deep external walls filled with insulation in addition to other components such as triple glazed windows and heat recovery ventilators. There is no expertise for this locally and it has not been costed in this setting - but I imagine it to be very expensive. If you were going for an 'alternative system' and were able to find someone to this I would use a hybrid of strawbale and rammed earth. Strawbale has inch for inch the same insulation as batts (except they are > 30 cm deep). I would run a rammed earth wall down the E-W spine of the building as thermal mass to store all the solar heat energy during the day. Re: Questions... 8Dec 09, 2008 4:55 pm harryfoster The most eco-friendly water bottle you could possibly use is a re-used glass bottle or jar. The most eco-friendly clothing you can wear is actually re-used, purchased-at-the-thrift-store items or hand-me-downs (even new organic items use up resources and energy to produce). The most eco-friendly dishes? You guessed it- a set from the local second-hand shop Too true - the sustainability mantra - reusable, recyclable, renewable. Re: Questions... 9Dec 10, 2008 10:05 am ... not sure of the relevance of water bottles etc ...
.. but while we are on re-use, the most eco-friendly rubbish bag you could use would be a re-used shopping bag... and yet people are jumping up and down trying to ban them! "Now, supposing a house to have a southern aspect, sunshine during winter will steal in under the verandah, but in summer, when the sun traverses a path right over our heads, the roof will afford an agreeable shade, will it not?" -- Socrates, ca. 400 BC Personally, considering your layout (study/work desks in bedrooms), I don't think you have any other option but to leave NW windows and make them as big as possible e.g.… 7 10455 We had this happen to us last year and got charged a variation. Try and give away as much as you can that is usable to charity otherwise if you are in Sydney I have a… 1 4477 Not sure what council area you are in. Some LGA's allow zero lot retaining walls. This usually occurs in greenfield developments but not often in established areas. You… 1 8212 |