Home insulation min spec 80s vs 90s vs today?

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Batman

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#115867 9-Apr-2013 20:57

I believe legislation to insulate new houses started in around 1980 ... Thing is, anyone knows what the difference in the insulation (WALL CEILING FLOOR) requirements comparing the 80s 90s and today's standard?

Eg how much better does a 2012 house retain heat compared to buying an 80s or 90s house?

We live in south of south island

Thnaks if anyone knows.

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#795873 9-Apr-2013 22:09

Don't know what older standards required. But for today's standards google "nz building code H1" (not allowed to post links sorry).

Also it would help to say why are you asking. Are you buying a house and wanting to know how well insulated it is likely to be? Are you checking that an existing house has been insulated correctly? Or are you just curious?

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#795879 9-Apr-2013 22:20

There will be quite a difference. The problem is that many spec building being built today are still built to the minimum specs of the day to keep costs down. If you are building your own home, it pays to overspec the insulation. this tool can help http://www.designnavigator.co.nz/

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#795892 9-Apr-2013 22:45

Buying house.

Wondering if buying 70s and earlier (ie no insulation in walls and floor - you can pay a quarter of the cost of the house to add ceiling insulation floor and double glazinG and still be cold as sh#% coz there's nothing you can do to the walls look i'm talking about the -4 nights of south not your lucky auckland winter)

Or 80s

or 90s (some quirky designed houses eg roof cavity = used as attic style bedroom with skylight - what ceiling insulation to expect?)

or 2005+

What kind of insulation efficiency to expect from the walls ceiling (as mentioned some quirky design means there isnt necessarily a roof cavity you can plonk batts into) and floor for houses of these 3 eras?

Duble glazing is obvious and you can add so i'm not discussing here

Stan

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#795895 9-Apr-2013 22:49

I hope this helps.

http://www.branz.co.nz/cms_show_download.php?id=b8793351c14fc42d511e811f0fd1543dff253e41

Edit: the bold bits on the 2nd page 1978, 1991, 2000 and 2007 with R values stated beside them

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#795930 10-Apr-2013 07:34

joker97: Buying house.

Wondering if buying 70s and earlier (ie no insulation in walls and floor - you can pay a quarter of the cost of the house to add ceiling insulation floor and double glazinG and still be cold as sh#% coz there's nothing you can do to the walls look i'm talking about the -4 nights of south not your lucky auckland winter)

Ceiling insulation isn't that expensive to add. I don't have time to do the sums properly, but perhaps $5K of insulation, and if you want someone else to install it then another $2K. Ish. Underfloor can be similar, depending on grants and house sizes, but I'm not sure how effective it really is. Maybe it's better for moisture prevention.

Proper double glazing is super expensive, but retrofit double glazing is 80% as effective and 20% the cost. I estimate $5K-$7K to retrofit a standard house. This will reduce condensation (you still need to get rid of the moisture), and keep heat in.

Wall insulation is the tricky one. It's not too expensive to have a foam inserted in the walls, but it shrinks, and there are questions around moisture. I've had it done, and opened up the walls in a few places, it shrinks slightly but not too much. The big issue is repainting.

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#795968 10-Apr-2013 08:46

The Branz link Stan posted should have all the info you need. But as a point of reference my office has designed some affordable homes for Auckland developments and we're putting R4 in the ceiling, R2.8 in the walls and we estimate about R2 in the floors. This is with double glazing throughout but we probably wouldn't change the insulation levels that much if the house was being built in Invercargill. Architecturally designed homes do tend to be insulated above code but it can be hit and miss pre 1999.

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#797012 10-Apr-2013 10:34

Odd question I am getting my first house built is there any reason the house is over spec ed for insulation its 2.2 on the walls and 3.2 in the ceiling its no flash expensive build are the sizes more common?

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#797357 10-Apr-2013 19:47

Stan: I hope this helps.

http://www.branz.co.nz/cms_show_download.php?id=b8793351c14fc42d511e811f0fd1543dff253e41

Edit: the bold bits on the 2nd page 1978, 1991, 2000 and 2007 with R values stated beside them

thank you so much!

so basically the minimum standard really didn't change between 1977 - 2007!

i guess the only way to know is to look inside or see a building book but those are hard to get in most houses for sale ... the other way is to live in it over a winter to compare with past experience but not really an option ...

thanks for the page though very very helpful :D

Stan

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#797445 10-Apr-2013 21:50

joker97:
Stan: I hope this helps.

http://www.branz.co.nz/cms_show_download.php?id=b8793351c14fc42d511e811f0fd1543dff253e41

Edit: the bold bits on the 2nd page 1978, 1991, 2000 and 2007 with R values stated beside them

thank you so much!

so basically the minimum standard really didn't change between 1977 - 2007!

i guess the only way to know is to look inside or see a building book but those are hard to get in most houses for sale ... the other way is to live in it over a winter to compare with past experience but not really an option ...

thanks for the page though very very helpful :D

You are welcome :)

It is worth noting that these specs are for the majority of the north island (excluding central plato) the south island has slightly higher spec'd insulation.

Also I have read somewhere in the early days of compulsory insulation 1 in 5 houses still did not have it. Might pay to take out a wall socket and check :)

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#797489 10-Apr-2013 22:49

that's why my cut off is 80s :D

hmm i wonder how much higher is the minimum for sth island ...

Regs

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#797491 10-Apr-2013 22:51

older houses can still qualify for the insulation subsidy... get in quick: "if your home is constructed prior to the year 2000 then it qualifies for a 33% discount off the installed price of the insulation up to a total of $1300 incl GST"

ceiling + underfloor to current spec makes a huge difference if you have an old bungalow/villa with wooden floors. my place went from 8degC to 15degC ambient temperature after fixing ceiling insulation and adding underfloor.

last i heard, it was around $18/m2 installed. For a 150m2 house Thats $5400 to do floor + ceiling. Take off $1300 for the subsidy and you're down to $4100.

some of the newer houses have a different problem - condensation. not enough ventilation can cause your house to be damp and therefore cold and sickly. You may end up having to install a HRV/DVS etc system which could cost you just as much, if not more.

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#797495 10-Apr-2013 23:02

Regs: older houses can still qualify for the insulation subsidy... get in quick: "if your home is constructed prior to the year 2000 then it qualifies for a 33% discount off the installed price of the insulation up to a total of $1300 incl GST"

ceiling + underfloor to current spec makes a huge difference if you have an old bungalow/villa with wooden floors. my place went from 8degC to 15degC ambient temperature after fixing ceiling insulation and adding underfloor.

last i heard, it was around $18/m2 installed. For a 150m2 house Thats $5400 to do floor + ceiling. Take off $1300 for the subsidy and you're down to $4100.

some of the newer houses have a different problem - condensation. not enough ventilation can cause your house to be damp and therefore cold and sickly. You may end up having to install a HRV/DVS etc system which could cost you just as much, if not more.

Can be false economy to go for the subsidisies I have heard, as the companies that can get it, can be quite a lot more expensive. Recall a story on campbell live or closeup about it some time ago.