Golden Bay eco home - most energy efficient house in the NZ

listed by Ecobob.co.nz

Golden Bay eco home - most energy efficient house in the NZ 

Well done this one :-)

Re: Golden Bay eco home - most energy efficient house in the NZ 

would be interesting to see the structure of walls and roof though.

Re: Golden Bay eco home - most energy efficient house in the NZ 

It's just standard framing and trusses not what we understand under nice crafty carpentry ;-)
Apart from that it's well done with decent windows, screed and heating.

Re: Golden Bay eco home - most energy efficient house in the NZ 

A NZ design incorporating a clever mixture of mostly NZ materials and building techniques. Here I was thinking that I had to use heavy walls and that it would bankrupt me to have R5 in the walls and R7 in the ceiling. Maybe some NZ building techniques, lifestyles and interaction with our environment (high UV, high salt etc) aren't the same as some anonymous place in Europe. Looks like they put the all savings from not using unnecessary air and vapour membranes toward extra insulation. Looks much better design than those fireproof bunkers and associated hand waving about thermal mass and solar gain.

Re: Golden Bay eco home - most energy efficient house in the NZ 

What is it this ever going tale about "unique" NZ conditions??
In New Zealand it rains, it storms, the sun is harsh, it is humid in places, there are frosts, there are earth quakes..... just like many other places in Europe, and elsewhere...?
So a building material or method works in NZ if it works in Europe, America or whereever...as long it is correctly done by qualified people.

Re: Golden Bay eco home - most energy efficient house in the NZ 

You didn't read what I wrote
I wasn't just talking about the weather I was talking about the house, the location and the lifestyle as well. A lot of our houses have European windows for instance but some of them open onto a deck facing the beach and have a lot more glass. If I start with a European design I might have to use all of it - if I mix and match with local ideas and products then I might need to consider how the European products fit in and their costs.

Re: Golden Bay eco home - most energy efficient house in the NZ 

European windows perform much better and they enhance any NZ building regardless of style or size of windows. Most NZ type windows are expensive for what they are.

Re: Golden Bay eco home - most energy efficient house in the NZ 

I know why you don't listen - its the same reason why you don't read

"I havn't studied the latest additions to the code in depth as I am too much in demand..." Followed by a lengthy discourse on why everyone else is wrong.

Re: Golden Bay eco home - most energy efficient house in the NZ 

"I havn't studied the latest additions to the code in depth as I am too much in demand..." Followed by a lengthy discourse on why everyone else is wrong.




Discussion pointless. I have read. Try straight English as I am no as sophisticated like you to understand some of your twisted sentences in your posts.

Re: Golden Bay eco home - most energy efficient house in the NZ 

Good morning

1. I'm quite surprised about the high HERS rating. How come?
2. @ Guess what. There is nothing crafty about Frames, neither here nor in Europe. One could argue about the roof structure .... but than i guess that trusses are cheaper. (but I know what you mean)
3. I don't know what nationality you guys have but instead of arguing we should combine forces. It is about balance and a nice living environment.

We should be happy about every change of mind towards change, but some people tread that subject like a state secret......

I don't understand the vanity of people when it comes to "sustainable building" ( hate that term).
no one knows everything...and there are more than one way to skin a cat......

Of course it is about money.... but the way the industry runs the show here in NZ is mafia like..

We (designer/builder/architects/engineers) shout
create a stronger bond/lobby to push the building sector towards more education and improvement.

Instead of listening/obey rules made by the industry to make an easy buck....

Use common sense. At the end of the day it is not rocked science to build a house. (neither here or in Europe).

Thank for reading and have a good weekend

Re: Golden Bay eco home - most energy efficient house in the NZ 

@zimmerer
With crafty I mean walls made with slot and tenon joints and such decent sized timber rather than 4x2 nailed together. I personally hate those trusses. In all houses I have lived in they were sagging in the larger rooms. In your experince what is the real cost difference between a rafter roof and trusses?
I am pushing exactly in the same direction like you do and with my work I clash from time to time with the mafia type establishment in the building industry and their resistance to any ideas from outside the scope they work in.

Re: Golden Bay eco home - most energy efficient house in the NZ 

I have recently taken a standard 120 sq m 3 bedrm house through full HERS certification - it is an entry-level house in west Auckland, built in an entry-level subdivision, with good sun orientation.

It is built only to code compliance levels except three enhancements I suggested to the developer:
1. Removal of all recessed lighting from the plans and replace with ceiling buttons - to enable blanket insulation on the ceilings - no additional cost to the build;
2. Increased ceiling insulation slightly (2.7 instead of 2.4 I think - I can never remember numbers, but it was definitely increased slightly above code) - additional cost about $500;
3. Install piping so that an external (outdoor) cylinder can be used - negligible cost difference. For the house that went through the HERS process, an integral HWHP was installed.

The house was be built with standard DG, not thermally broken. And from the developers point of view, to save on concrete, the house has a concrete ribraft foundation with the polystyrene waffles, again not thermally broken between the blocks nor at the edges.

The house achieved a rating of 8.

When I reminded the certifier that the floors of an entry level home is carpetted, the rating dropped to 6.5, and the resulting certified HERS rating is 6.5. Access to the thermal mass from solar gain is the only thing that changed from one rating to the next.

The expected annual home heating bill for this house is $240 using electric radiant heaters. I note that the certification did not have any drapes on the DG windows, which should result in lower heat loss - I can't recall whether the house had pelmets - which would have been easy to do for these box type designs.

I was actually pleasantly surprised that a code compliant entry-level house can achieve these ratings. It means to me that more people would be able to access low[ish] energy homes, even in the absence of thermally broken everything, enthalpy recovery ventilation systems, super efficient space heating technologies, expensive heavy curtaining, etc.

(Note: The hot water service has a separate HERS rating as opposed to the house HERS above. For this house the installation of the HWHP at the as-built stage meant that there were no additional plumbing, labour and electrical costs, and the difference between the HWHP and a standard electric cylinder was less than $2k for the developer. This is beyond the amount most entry-level buyers can afford).

Re: Golden Bay eco home - most energy efficient house in the NZ 

Sorry Guess what? I must confess that I'm a bit of a sceptic when it comes to some of the building products and systems from overseas.

I had the misfortune of living for a period in a rental that was built using a system introduced into NZ by a European builder. I had always been a sceptic of the promo's that said the houses were warm because they looked warm. Not surprisingly the house was cold and noisy because it was all hard surfaces and no proper insulation in the walls. The system exploited the minimum code requirements. I met the designer of the system at an industry function when I was starting out in the building trade and after introducing myself and making the polite comment that I had lived in one of his houses he responded with:

"If you ever say my houses creak I'll sue you!"

and stormed off in a huff leaving me even more sceptical of European dogma.

Apparently efforts by the establishment to increase the minimum insulation requirements was a threat to his family fortune and therefore all kiwi builders who were not enamoured of his system were the enemy.

Thanks in part to his tireless efforts the minimum requirements have remained pathetically low. Eventually insulation was added to the walls of the system at the expense of ridiculously large areas of glazing and now from what I read he expects us to trust implicitly all things European.

I remain a sceptic

Re: Golden Bay eco home - most energy efficient house in the NZ 

Of course you have to be cautious about anything regardless from where it comes from.
However I have lived in warm and dry and comfortable European houses and I have lived in cold, damp, drafty and mouldy Kiwi houses.
The European way won't work well if you don't do the work on site properly.
I take all building methods and materials with caution, but I do find a lot of things in the NZ building industry scary, very scary

Re: Golden Bay eco home - most energy efficient house in the NZ 

Agreed Guess what?, but what scares me most is they way that our building code and the efforts to implement it get over-ridden by clever marketing pretending to be fact.

For example where a system comes in two variants - a minimum code or less version and an above code version then there needs to be a way for home owners to tell the difference otherwise marketing wins over fact and the home owner loses.

To be useful to the people that matter, the home owners, this forum needs to be able to openly discuss some of the simple things like independent proof that things have been tested and work in the NZ context. This will not happen whilst the general rule is that sponsors of the forum are not to be challenged.

Here is house that works and its not not associated with a particular propriety system but someone has taken the time to document it and make it available in a format that the home owners can evaluate for themselves. That presents a nice challenge to some of the propriety systems to lift their game.

Re: Golden Bay eco home - most energy efficient house in the NZ 

@ seeker
That is interesting
I'm going to build a house soon. It's getting build with a pre-build panel system. Here are the specs:
Walls:
7mm ply, 140mm stud work (without nogs ) and cellulose (blow in method) insulation, Intello, 45mm service void with cellulose as well.
Roof:
Scillian roof, HyJoist/HySpan 300mm, cellulose as well, Intello
Floor:
90mm Sub floor with again cellulose.
Windows:
PVC partly triple glazed

HEDRS rating 7 ;-)

That is the crux of that matter. Nothing within the building industry compute. They/It can't cope with the higher/increased expectations of the customers.
(and they better do because we are not going backwards)

Personally I think that we need a fresh start and Christchurch would be good for it.

@guess what
It all depends from the design of the roof but it's hard to say sitting here in front of my fire ;-). But if you want more infos ...ingo at true-carpentry dot co dot nz. I need to see the drawings.
Basically trusses are economical but a wast of space (attic).
I totally agree with you in terms of the timber dimensions. Those sticks doesn't look nice in exposed situations. For me it doesn't matter whether exposed or not the process to cut and put them up is the same. But say....two days to cut and two days to put them up...

Mortise and tenons are used in old buildings. (Fachwerkhaus) If you want a building like that we still do it but with special designed tools. We also using that kind of method for exposed roof structures or other timber constructions (pavilions /carports and so on)

@gaz
like your last commend

Re: Golden Bay eco home - most energy efficient house in the NZ 

@ zimmerer
What Chch needs is a true group builder approach and not the inevitable hand over of all the money to one company that then drip feeds it out to all the 2 man, limited liability, building operations.

Perhaps the building industry could be set some basic rules like walls must be either 140mm (& proportionally higher R-values) or use thermal mass with current minimum for framed walls. Another could be no 190mm skillion nonsense. Surely that type of challenge should be cost neutral given the benefits of scale.

Otherwise the established $/m2 values will set the cost and the minimum code will set the standard.

It's good to see that we are finally getting over the cringe factor associated with the 70's & 80's government funded macerated paper installs. Cellulose can be a fantastic product but in NZ it needs the person who matters to supervise its installation.

Re: Golden Bay eco home - most energy efficient house in the NZ 

Yup. that could be one approach. But who can/will be the driving force behind it. We (builders,architects,designer a.s.o.) have not really a good stand/lobby (why not?we are actually building the houses)
Maybe we can start with a group of keen guys willing to work as a team and doing it for the community sake rather than a chip on the shoulder ;-)
in the era of emails and so forth it might be worth to use this forum as a platform to get started.

I for my part am willing to do my share.

Re: Golden Bay eco home - most energy efficient house in the NZ 

can anyone explain to me what the
HERDS rating
stand for
thanks