Browse Forums Heating, Cooling & Insulation 1 Mar 16, 2015 8:24 pm Hi all, Building our first home and looking at insulation. 2 builders quoted an allowance for R2.5 in Roof and 1.5 in the ceiling. However checking http://www.yourhome.gov.au/passive-design/insulation it has the same values for every location except for Thredbo. Is 4.1 in the roof and 2.8 in the walls too much or have we been getting under spec'd for our insulation? Re: Insulation R rating - Can you go to high? 2Mar 16, 2015 8:30 pm Where abouts are you located? Location and climate determine how much insulation you need. You can not really have too much, although too much reflective insulation = great for preventing summer heat, but no so good at retaining heat in winter. Bulk insulation better at retaining heat in winter, so too much will not be as good if you were in a hot environment with mild/warm winters Dale - Building Newbie Proserpine, QLD Re: Insulation R rating - Can you go to high? 3Mar 16, 2015 8:55 pm As pointed out, depends where you are.. but we upgraded to 3.5 in our house.. should be plenty.. we also have 50mm anticon sarking under our colourbond roof. Paddington 29 @ Blue Horizon Estate (Lot 105, Wattleridge Crescent, North Kellyville) Our Build Progress Blog: http://light487.wordpress.com/ Re: Insulation R rating - Can you go to high? 4Mar 16, 2015 9:21 pm Gunna 2 builders quoted an allowance for R2.5 in Roof and 1.5 in the ceiling. Did you mean R2.5 in Roof and 1.5 in the wall? This doesn't meet the Building Code minimums so they are underquoting. Normally to achieve a TOTAL R value of 4.1 with typical roof construction you will need R3.5 batts (see this link for the calculation http://www.anewhouse.com.au/2013/07/ins ... nsulation/) The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Insulation R rating - Can you go to high? 5Mar 16, 2015 9:22 pm Sorry, in Ipswich. Western Brisbane Requesting a reflective membrane under colorbond roof for summer heat prevention and what should I request in roof and walls? We will be having ducted air so want to minimize loss of heat in winter and cool in summer Re: Insulation R rating - Can you go to high? 6Mar 17, 2015 7:50 am In that case, you will get benefit from both reflective foil insulation and batts (bulk insulation). The reflective insulation (such as air cell) will help in summer to reflect the heat, whilst the bulk insulation will help keep the cold air inside (and also the heat in winter). Make sure you look at window size and orientation too - can lose a lot of the cool air from the aircon via the windows Dale - Building Newbie Proserpine, QLD Re: Insulation R rating - Can you go to high? 7Mar 17, 2015 8:32 am If you are building using 90mm timber framed walls then you can get R2.5HD batts . For the ceiling I'd suggest R 3.5 minimum preferably R 4.0. The more the better but as with anything it is a law of diminishing returns. Sarking as a minimum ( with a few whirlybirds and eaves vents) for under the roof sheeting or an R 1.5 foil blanket is even better. A with what DM says above, your windows will be your weakest link. Standard single pane glass window only have an R rating of 0.5 - 0.75 so you will need good thermal curtains for winter and shading for summer. I know it all comes down to cost but you will end up with a very comfortable home plus reduced long term energy bills. Stewie Re: Insulation R rating - Can you go to high? 8Mar 17, 2015 8:40 am Stewie, what are your thoughts on window tinting that blocks sun energy etc in relation to locking out heat and locking in heat, does it have much of an effect or just sales speak? Paddington 29 @ Blue Horizon Estate (Lot 105, Wattleridge Crescent, North Kellyville) Our Build Progress Blog: http://light487.wordpress.com/ Re: Insulation R rating - Can you go to high? 9Mar 17, 2015 8:49 am light487 Stewie, what are your thoughts on window tinting that blocks sun energy etc in relation to locking out heat and locking in heat, does it have much of an effect or just sales speak? I will jump in here and say that personal experience of reflective film, not tinting, is the effect is huge particularly for west facing windows. When we had some installed one summer afternoon even the installer was amazed at the difference it made. The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Insulation R rating - Can you go to high? 10Mar 17, 2015 9:10 am bashworth light487 Stewie, what are your thoughts on window tinting that blocks sun energy etc in relation to locking out heat and locking in heat, does it have much of an effect or just sales speak? I will jump in here and say that personal experience of reflective film, not tinting, is the effect is huge particularly for west facing windows. When we had some installed one summer afternoon even the installer was amazed at the difference it made. Yes, that's the stuff I was meaning. It's practically clear, though I believe you can get different grades of tinting if you wanted, but reflective of UV and solar energy etc. We have two west facing bedrooms on first floor and a small thin window downstairs that we were thinking of applying it to. Paddington 29 @ Blue Horizon Estate (Lot 105, Wattleridge Crescent, North Kellyville) Our Build Progress Blog: http://light487.wordpress.com/ Re: Insulation R rating - Can you go to high? 11Mar 17, 2015 9:35 am Looked like a mirror from outside but from the inside really just like a grey tint. Just one word of warning is to shut the curtains at night . . . that mirror effect only happens when it is brighter outside than inside! The Harder You Try - the Luckier You Get ! Web site http://www.anewhouse.com.au Informative, Amusing, and Opinionated Blog - Over 600 posts on all aspects of building a new house. Re: Insulation R rating - Can you go to high? 12Mar 17, 2015 9:50 am bashworth Looked like a mirror from outside but from the inside really just like a grey tint. Just one word of warning is to shut the curtains at night . . . that mirror effect only happens when it is brighter outside than inside! lol.. so no late night office shenanigans? Paddington 29 @ Blue Horizon Estate (Lot 105, Wattleridge Crescent, North Kellyville) Our Build Progress Blog: http://light487.wordpress.com/ Re: Insulation R rating - Can you go to high? 13Mar 17, 2015 10:31 am Quote: I will jump in here and say that personal experience of reflective film, not tinting, is the effect is huge particularly for west facing windows. When we had some installed one summer afternoon even the installer was amazed at the difference it made. Similar to what friends of ours told us when they did that to their place too Bashworth. Note though that while it is excellent for helping keep the heat out on those windows during summer it doesn't do much to help keep the heat in during winter. Stewie Re: Insulation R rating - Can you go to high? 14Mar 17, 2015 12:09 pm Stewie D Quote: I will jump in here and say that personal experience of reflective film, not tinting, is the effect is huge particularly for west facing windows. When we had some installed one summer afternoon even the installer was amazed at the difference it made. Similar to what friends of ours told us when they did that to their place too Bashworth. Note though that while it is excellent for helping keep the heat out on those windows during summer it doesn't do much to help keep the heat in during winter. Stewie Ok thanks for the confirmation on that Stewie. One of the sites I saw that on seemed to imply that it contained heat within the room by having them there.. I found that a bit much to swallow. At least with insulation, reflective films, weather guards and so on, we can at least minimise the loss of heat/cold from the house.. that's all you can do really.. minimise/mitigate.. Paddington 29 @ Blue Horizon Estate (Lot 105, Wattleridge Crescent, North Kellyville) Our Build Progress Blog: http://light487.wordpress.com/ Re: Insulation R rating - Can you go to high? 15Mar 17, 2015 7:19 pm All our bedrooms are on the South-South West side so will get a little arvo sun but I think it will be ok with the insulation and curtains Was advised by the builder that 2.5 in the roof comes with the house so upgrading to R3.5 in roof and R2 in the walls hopefully wont cost to much. Thanks mate. Yeah good points! Leaning towards Option 3 to get a bit extra space in the cabinets but not going too crazy high (and expensive). Would require a mini… 13 39457 It will be neat but you won't have much freeboard. At least they are not weep holes. Are you in a high intensity rainfall region? 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