NZ house building is there a light at the end of the tunnel?

Forums › Home Workshop DIY › NZ house building is there a light at the end of the tunnel?

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#2662081 24-Feb-2021 09:29

@Jase2985: Yeah I am not even looking at price yet. Just the fact that things are not available not even as 1:1 replacement products.

@Fred99: Yeah I know Knauff and asked for a price. About 5x the price of Earthwool!!!! (more like 30% in other countries) and that is so lopsided that it's a no brainer. Basically you can say the product is not available in NZ. They just use if for speciality case installs mostly on commercial.

I'll need to have a look at Ecoply. Looks interesting but not sure it does what ZIP does yet. Thanks for that!

As for tems, Wellington 5 degrees feels like -10 in Europe at least inside your normal house. It is not about temperature but climate. You want every room to be the same temp and move slightly in temp with day/night cycle but be the same temp all throughout the year no matter what outside temp does. Northern US and Canada mainly have more exterior insulation which we don't have but wall cavities are similarly built.

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Jase2985

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#2662082 24-Feb-2021 09:30

Fred99:
Jase2985:I suspect if you went to the effort of importing most of your building products you could've save quiet a bit on the cost of the build.

Yet when governments have investigated the industry for price gouging, the outcome hasn't supported the "common knowledge" that we're getting ripped off. (Except for a few cases where supply companies colluded to avoid competition.
Retail markups on many building materials in NZ are huge.

doesnt really matter were the markup is, its the consumers that suffer, and it shows with the amount of houses being built, and the prices that have skyrocketed

Jase2985

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#2662086 24-Feb-2021 09:40

earthwool is knauf

i used it in my garage build

https://www.bunnings.co.nz/earthwool-glasswool-r2-4-90mm-x-580mm-x-1160mm-13-46m-wall-insulation-batt-pack-of-20_p0224626

Gives you 13.2m2 coverage for $122

https://www.bunnings.co.nz/pink-batts-10-2m-classic-r2-4-glasswool-wall-insulation_p0054835

Gives you 10.4m2 coverage for $118

Comparing to mamoth for isntance you can only get R2.5 in a 90mm stud vs R2.8 for earthwool. same goes for 140mm stud, R2.8 vs R4.1

olivernz

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#2662109 24-Feb-2021 10:49

@Jase2985: Used Earthwool in my extension in my last house. Not bad stuff and nicer than pinkbatts but I still prefer Greenstuff just couldn't get it at the time and I was on the clock. We'll see what I will end up doing eventually But would have still preferred rockwool stuff. Even better R value and more vermin proof

Fred99

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#2662129 24-Feb-2021 11:30

Fred99:

Yet when governments have investigated the industry for price gouging, the outcome hasn't supported the "common knowledge" that we're getting ripped off. (Except for a few cases where supply companies colluded to avoid competition.
Retail markups on many building materials in NZ are huge.

Jase2985:

doesnt really matter were the markup is, its the consumers that suffer, and it shows with the amount of houses being built, and the prices that have skyrocketed

Sure - it's the consumers who suffer, but there's a distortion in the market if builders rely on mark-up on materials supplied to make their businesses viable (and yet even in "boom times" small building companies seem to have a spectacular rate of business failure).

I do wonder what the "extra" discount structure is for "large" group housing companies. When I did some building work a couple of years ago, trade discount from retail price for (most) fastenings was 60%, framing timber exactly 50%, there were a few exceptions where discount was lower, not really surprising when for some items that needed to comply with NZ standards there was effectively only one local supplier.

Anyway I suspect that the difference in cost to build a "bespoke" house in NZ vs a cookie cutter could be particularly high, you'll be paying more - especially if you're using materials that aren't "common" and you're a small building company not able to enjoy huge discounts. Then the whole thing WRT seismic design and the "leaky home" saga, you'll probably be paying massively more for compliance costs / professional fees if design work etc isn't something copied thousands of times with minor tweaks.

Disrespective

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#2662188 24-Feb-2021 13:20

As someone who is an architect, and has designed a couple of houses based* on Passivhaus principles, I feel confident to comment.

I agree that the NZ building industry is ridiculous for many reasons. However we are also such a small market that it's hard to generate enough interest in some products for economies of scale purchasing to have major effects. That said, we do have tried and tested products in our market that will do what you want, if your budget allows for it. You can also import certain things yourself if you felt up for a fight too...

If you can't find useful resources I would start talking with Proclima personally. They produce/import the airtightness wrap layers required to limit air changes in the house. Their tech team have been fantastic resources for me in the past and not only know the science behind the complete system build-ups but also can recommend products that work with their wraps as managing moisture in our homes is a bit different when building this way.

From there I would talk to one of the Zehnder installers (There are alternative heat recovery brands out there too) about their systems to get a design in place which is based on certain wall/floor/ceiling construction methods and insulation values. Their design should be able to provide calculations which show energy gains and losses from the design over the course of the year. If they use the designPH sofware it is extremely versatile and specifically intended for Passive homes.

I've had personal meetings with the guys from eHaus Kapiti and been extremely impressed with their knowledge on the processes but keep in mind these discussions were informal and not related to any specific design.

* - Actually having your home certified as passive (going in the international directory) costs money, let alone the extra work/money required to actually incorporate all the features/tests necessary.

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#2662305 24-Feb-2021 20:20

Jase2985:

...

I know of at least 3 different building companies, 2 in ALK ...

Care to share?

Please keep this GZ community vibrant by contributing in a constructive & respectful manner.

gzt

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#2662312 24-Feb-2021 20:40

Yeah kudos for Govt doing a bare minimum. But they so missed the goal. Sure new builds have double glazing but the frames are still solid aluminium.

Even so this makes a massive difference for much of the cold period. As you mentioned some designs could be inadequate in areas with significant high average winter wind. That could be an area where standards need a look and an upgrade for some scenarios, in turn driving product availability.

Kickinbac

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#2662399 24-Feb-2021 23:21

I’ve heard that BRANZ is a problem with importing building matetrials, it’s expensive to get products tested and approved for use. This can discourage importing of innovative building products particularly if they will never be high volume.

neb

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#2662839 26-Feb-2021 02:27

Fred99:
Anyway I suspect that the difference in cost to build a "bespoke" house in NZ vs a cookie cutter could be particularly high, you'll be paying more

It's not just costs, it's availability. We tried to do the Casa de Cowboy redo with as many European components as possible but in the end had to give up, after losing about six months of build time in chasing down suppliers and supplies from companies that were perpetually unable to deliver or even provide a delivery estimate we gave up and fell back to the stuck-in-the-1960s stuff that others have mentioned. So unless you want to go crazy chasing down things that you'll probably never be able to get in the end, you have to go with a small amount of European material and then a lot of lower-grade other stuff. At least we got Homerit uPVC windows.

Fred99

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#2662874 26-Feb-2021 08:20

neb:
Fred99:

Anyway I suspect that the difference in cost to build a "bespoke" house in NZ vs a cookie cutter could be particularly high, you'll be paying more

It's not just costs, it's availability. We tried to do the Casa de Cowboy redo with as many European components as possible but in the end had to give up, after losing about six months of build time in chasing down suppliers and supplies from companies that were perpetually unable to deliver or even provide a delivery estimate we gave up and fell back to the stuck-in-the-1960s stuff that others have mentioned. So unless you want to go crazy chasing down things that you'll probably never be able to get in the end, you have to go with a small amount of European material and then a lot of lower-grade other stuff. At least we got Homerit uPVC windows.

Same if you need something local but "custom" rather than off the shelf.
I wanted new cedar french doors with heart rimu jambs made to match 3 other pairs in the house. 20 years ago finding joiners who had the skills was no problem. Now almost everyone uses aluminium or PVC joinery. The few "real" joiners left in the business here were telling me that they needed at least 6 months lead time. I did get them made more quickly (a couple of weeks) - but only by using the grapevine to find a retired joiner who had a workshop at home and liked to tinker around (to escape from his wife for a few hours a day was his explanation).

neb

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#2663073 26-Feb-2021 11:15

Fred99:
I did get them made more quickly (a couple of weeks) - but only by using the grapevine to find a retired joiner who had a workshop at home and liked to tinker around (to escape from his wife for a few hours a day was his explanation).

You've met my dad then?

Fred99

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#2663104 26-Feb-2021 12:44

neb:
Fred99:

I did get them made more quickly (a couple of weeks) - but only by using the grapevine to find a retired joiner who had a workshop at home and liked to tinker around (to escape from his wife for a few hours a day was his explanation).

You've met my dad then?

Maybe. When I called him I was trying not to sound too desperate even though I was, I had about two months to get the doors and everybody else had been saying six months minimum. When he came around to measure up, I served him baking I rushed out to buy from a local deli and pretended my SO had made, served tea in our best teacups with silver spoons, and gave him a big jar full of honey from our hive. A couple of days later he called back with a price (less than I expected), and apologised that he was a bit busy - so it would take him a "couple of weeks" to deliver the doors - which he did - and a perfect job he made of them. The jambs needed to be ~300mm deep, the other firms were going to use pacific rimu because they claimed they couldn't get NZ heart rimu to suit, but I guess he had a stack of timber stored in his shed. Extra happy because they were delivered so early, I had plenty of time to prep and varnish them with oil-based finish weeks before we installed them.

If he needed more business, then he'd have been an ideal candidate for the thread in the off-topic forum about people going above and beyond, but he didn't want more work than the specialised small jobs he was already getting by way of word of mouth, in my case talking to the retired owner of quite a large specialist timber supplier supplier that used to also manufacture timber joinery.

bfginger

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#2663270 27-Feb-2021 07:11

And the the worst is the the so called SMEs haven't got a clue.

They really don't. What's more they'll think you are mad if you want modern thermal and ventilation design.

What matters is price point and the big one: being "on trend" which translates to making each house monochromatic and having a granite benchtop.

In places as cold as Central Otago they're building minimum spec subdivisons with solid aluminium joinery, second rate low-e glass and minimum spec R value walls.

The cost of manufacturing R2.5 should be minimal over R2.2. There is no justification for the code allowing R2.0/R2.2 batts on external walls.

Despite what people think the manufacturing cost of thermally breaking aluminium windows would be minimal at around 4% extra. People end up with high quotes because they're comparing a mid range profile with a break almost nobody buys against a standard profile without. Only one manufacturer (APL) has been doing a standard profile with a thermal break.

k1w1k1d

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#2663320 27-Feb-2021 12:11

Is the standard NZ house with Gib, 90x40 framing, vapour barrier, external cladding, and some form of insulation shoved in an acceptable building method to start with?

Quite a bit of the wall has thermal bridging through the frame, so lowers the overall R value of the wall.

140x40 framing allows thicker insulation to be installed, but still has the same thermal bridging.

What alternatives are there at an affordable price?

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