Meant to say the hot water heat pump controls could divert warm water to the slab when necessary.

JK

Is the internal temperature of the house designed to stay reasonable all year round without even minimal energy fed into the floor via pipes in the slab? I can't see how it will.
I'm not deriding anything. However a polished concrete slab below 20c is not that pleasant and I don't think it will stay above this right through winter.
Pipes in the slab and controls on the hot water heat pump would resolve any doubts without huge cost.

JK

Hi Nickoftime, Thanks for your question. Yes, you are right; there will some minor thermal bridging at the rib raft beam areas. How much we loose, I’m unsure of. However it’s going to be minimal and won’t impact on the performance of the house.
The choice of foundation is driven by economics and performance ;- ) so its balance between these factors I think.

Do the ribs act as a thermal bridge thus reducing that excellent R8 value?

Hello Russell,

This subject was covered under 'Treatments' (select any post with that heading).

You may find some of the answers there - regards Rex

Rib Raft Foundation system for Coatesville being laid. 300mm thick polystyrene pods form the basis of the insulated platform and Rib Raft. We expect to achieve an R value of 8 with the polystyrene pods and the 140mm concrete topping over will further increase this. This achieves a super high insulation value, keeping all that radiant energy in the slab where we need it.

What wouldbe the difference in load sharing in two cases?
Tall R.C.C. building with all walls (internal aswell as external) as R.C.C. structural walls,in which type all walls columns,beams are casted together(like in aluminum formwork as aluminiumsupplier(dot)com(dot)cn/ProductsList(dot)htm like in Mihan or similar)
Tall R.C.C. framed buildings with walls as partitionwalls and non structural members in which frames are made first and non structural partitions later.
With respect to following points
1) What type of loads R.C.C. walls wouldcarry?
2) Would bending in beams in both the casessame or different ?
3) Would columns carry same axial force andmoments in both the cases?
4) Would these walls act as shear walls?What would be their role with respect to lateral loads?
5) If these walls are discontinued at stiltfloor what precautions are taken to offset such high stiffness discontinuity?
6) In analyzing such frames with structuralwalls how these walls are modeled?
Thank you ,very much.

I followed your link to the Australian codemark. It's only for board and not SIPs panels and only valid in Australia.

What's the big deal about what happens in Canada and why is it relevant to this forum? If the product has got a codemark for New Zealand then that's what is relevant here. You obviously have some axe to grind.

I've been reading these posts for a long time now and it really annoys me that Ecobob readers whine endlessly about how poor the standard of construction is here, but as soon as somebody offers anything better there's too many of you who can't wait to tear it down before it has a chance.

As far as the regulations are concerned you simply need to have the prescribed opening windows.

There are going to be two reasons to ventilate, moisture control and adequate fresh air for habitation.

If you want a simple prescription for moisture control, it might go like this...extraction in rooms where excess moisture can be generated ie kitchen, bathroom and perhaps laundry (you would need one way vents from the ducting to the outside otherwise your airtightness is affected) and venting of the house each day to remove general moisture build up.

The theory behind venting for moisture reasons goes like this, for a winter situation...suppose the inside and outside humidity is 80%, the outside air will be colder so if you open up the house to get an air change the colder air from outside will warm due to the thermal mass of the house, and it's relative humidity will drop so you now have air with lower humidity ie you have removed moisture from the house.

This leaves the question of air for habitation. I haven't researched this (but have kept myself supplied with oxygen for half a century) and I suspect the overnight requirement is relatively low. You could leave a window ajar to suit or have a trickle vent or have an exhaust or supply fan (perhaps one of the wet area fans) that can be set to a particular air flow rate. The later is available overseas but not sure of availability in NZ.

Having an airtight house and then doing something like having windows ajar may seem crazy but, firstly, there are other reasons for airtightness such as reducing moisture in walls and thermal improvements in same, but you need to compare the effect of that open window versus the heat lost via a mechanical ventilation system.

My understanding is that in mild climates the thermal gains of MHRV are marginal when compared to the cost. It really depends on how you want to live in the house, a more automated approach or taking care of a few things yourself.

Hi Sarah,
Excellent questions. I am really pleased someone has raised these questions as I have thought the same thing myself. The option that I chose was mechanical ventilation BUT I would be very interested to hear the Passive solar experts advice on this one.
As for no loft space, I understand it is possible to put the vent ducts in the floor slab although you would have to have a heat exchanger unit tucked away somewhere.
The choice between active (controlled) and passive ventilation seems to be one of the major differences between passive house and passive solar. It seems to me that the level of ventilation on a passive solar (natural ventilation) would often be too little or too much depending on how windy it is

hi,
We're at the start of the design phase of a house in Auckland. All bed and living rooms facing north, good thermal mass, above code insulation & glazing etc. Solar hot water and possibly Vectors PV & battery package.
What is the latest in acceptable untreated timbers that people have got council(s) to accept for both internal framing, lintels or even bottom plates?
We're also interested in the Living Building Challenge, although not as far as on-site sewerage treatment. (small 513m2 inner city site on volcanic lava flow - so expensive rock breaking to dig anything)

regards
Russell

Hello there

We are going to be building a pretty airtight Passive Solar house in Nelson. Not a Passive House though!

I've been doing loads of research on ventilation, and everything for 'almost' airtight houses seems to state that you need active ventilation, ideally Mechanical Ventilation with Heat Recovery. I can see why this is better in lots of ways, particularly in terms of control, but we are hoping for a more natural system. Our house design doesn't have a loft space for the ducting, we have concerns about the ducting harbouring germs etc, maintenance etc over the lifetime of the building and system, plus the cost of installation! Also is it really necessary to go to such lengths if our house is well insulated and heated in our part of NZ?

Our site has a good breeze a lot of the time, and the current plan has a clerestory window in the hall outside the bedrooms and also a high ceiling in the living area.

It seems conflicting to make the house airtight with high performing windows, and then have holes for the ventilation, but we know we have to 'Build Tight, Ventilate Right'. How do you know that trickle vents will be enough? And if the they don't prove to be enough, then can you 'enhance' them down the track, e.g. with a mechanical extraction system? We will have extractor fans in bathrooms and the kitchen anyway.

Trouble is, once you've put the vents in then you have compromised the airtightness and a MVHR system won't work effectively.

We want to do this right so our house is warm and healthy, but I've got so confused!

Thanks for your thoughts in advance,

Sarah

Hi Elrond,
Thanks. The Greek Island project looks promising and makes good sense. The clients had strong ideas about ‘bioclimatic design’ which they and their architect have worked it through the design- great to see.

Hi PTA,
The Burrows also looks like a fun project, architecturally and PH wise. You must be looking forward to its construction.

Wow... that didn't take long!

Magroc has removed the the CodeMark logo that they were not licensed to us but replaced it with a scummy:

'CodeMark for Australia & NZ nearing successful completion'

and the Canadian investor website have the equally devious:

'MagRoc is currently completing a successful national "Code Mark" for Aus/NZ'

Can't find anything in the JASANZ rules that allows applicants to preempt the outcome and it can't undo the damage already done by the misleading investor promo's and the Google cache evidence of their behaviour.

Would you trust people that behave like that? I know I wouldn't!

MgO continues its history of smoke-and-mirrors. I wonder if they have actually tested the product that is assembled in NZ with NZ foam, NZ adhesives, local equipment etc. Looking at the internet pictures of BEAL's outfit - a portacom and garage/workshop, and reading the appraisal certificate, I doubt that they have done much testing locally.

I wonder when someone in the MgO SIP's business is going to front up with some real life test reports instead of vague references to equally vague certificates. They seems to be putting a lot of faith in their view that once they get that elusive certificate regulators will be forced to accept the product without question. Too bad that CodeMark's days are numbered because no-one wants to buy products that have to use tactics like that to avoid fronting up with test results.

And a Passivhaus I'm designing for a rural location in the north of the uk, which due to its connection with the landscape is heavily reliant on orientation for passive solar gain.

http://paultestaarchitecture.co.uk/portfolio/the-burrows/

Here's an example of a PH being designed on a Greek Island (Ie with plenty of sunshine!) in the local vernacular and using full Bioclimatic design principles - http://www.passivehouseparos.com/bioclimatic-architecture-design/

Ooops, looks like my last post got cut short.

Solarei - Actually I disagree, I think you and I have very similar feelings about architecture in NZ and are not poles apart at all. I'm not sure you understand the Passivhaus approach yet though so it might seem like we are poles apart.

There's no conflict between vernacular architecture and PH - on the contrary PH traces its legacy to vernacular architecture in diverse locations around the globe, including places as different as Scandinavia and China.

Congratulations on the North Waikato house - it sounds like it is lovely and uses considerably less energy than typical NZ houses and sounds much more comfortable than typical NZ houses also. I imagine you have very satisfied clients too.

Hi Nzsparks;
Yeah well I guess that’s my issue then, ‘it has nothing to do with the outside world’. I can’t digest that....not for NZ anyway.

The attached 240m2 house achieved, 3200 Kwh for one year in 2011. It dropped to 17 degrees mid-winter 5 am, 3pm it was at 24 degrees.

The house is designed for optimised passive solar gain and passive ventilation. By passive ventilation I mean you can open the windows allowing fresh air to enter when you like( through a designed air strategy). It has a central clerestory which functions as a climate chimney over summer (stack effect).

The house is located in central North Waikato, has above code insulation for walls, ceilings and slab. Uses regular double glazed glass and was built for $2000per/m2.

I’d be interest to know what the PH statistics are like.

Its all about designing a healthy indoor environment. It has nothing to do with the outside world. If anything it easier to reach in new zealand with warmer temps and more sunlight.

Let heat in through windows or heating. Store heat in thermal mass. Keep heat in with airtight and thermal envelope.

The local weather determines what size windows, eaves, thermal mass and insulation.

Solarei may I ask what the energy use of your house is. And do you keep it above 21/17 deg year round

Thanks Elrond. Appreciate your explanation.

Its really interesting to hear what you say and the PH approach. I really feel we are poles apart in our thinking.

Let’s define what PH is, I think this will help:
PH is about designing buildings/ houses with efficient thermal envelopes, minimal/ or no thermal bridging, regulated air control and air pressure and making climate adjustments for regions/ countries and occupants. Following the PH method you can achieve low energy use and comfortable internal temperatures in most temperate climates- right?

My thoughts are there’s tremendous climate differences between NZ and Europe (please refer to the data below) and there are many cultural differences, beyond what you’re saying. Sure NZ is a Western culture. However Europe has significantly larger populations (hundreds of millions) with limited access to affordable land and resources. NZ is not like this (although this is changing). The reason why PH works in these countries is because it was developed for their climate types under unique cultural conditions. These countries do not have the same opportunities as NZ does given restricted climate conditions and cultural restrictions for building. All PH is doing is transplanting an advanced building system on the other side of the world and making it work. Because the math stacks up doesn’t make it the correct fit. This type of thinking is no different to imperialism, one advanced culture dominating the inferior and over the past one hundred years this has accelerated all over the architectural world. It’s hard to work out if a house or building has been designed for the UK, DUBAI, BANGKOK or NZ. Architects, Engineers parachute in from different countries, work out there calculations and designs and then fly out. I don’t think PH is any different; even though the intentions might be good.

My position is that buildings and houses can be designed in such a way to reduce or eliminate the need for machines and dependency on High-Tec materials. It all starts with the local site and climate. (Don’t agree with your comments in saying PH is not High-Tec; - It uses sophisticated calculations methods combined with advanced materials and construction methods to produce its houses).

New Zealand has a unique set of climate conditions (like any other country or region) which the country is still working out how to deal with. These climate conditions need to be carefully considered to produce smart climate engaging designs- typically referred to as Vernacular architecture. PH is not about this.

NZ needs to develop its own approach to how it produces low energy warm comfortable houses if it is ever to make any progress. We can learn certain lessons from PH ( mainly through the thermal envelope), but ultimately and how ever its sold to clients, its always going be an overseas based model made to fit NZ with many limitations.

Germany annual average sunshine hours : Berlin: 1623 sunshine hours Hannover: 1501 sunshine hours Berlin average winter temperature 3 ⁰

New Zealand annual average sunshine hours: Auckland: 2007.5 sunshine hours Christchurch: 2142.2 sunshine hours Auckland average winter temperature 8⁰

Just got off a Skype call with Jon from ehaus http://www.ehaus.co.nz, NZ's own Passivhaus experts. So look out for a followup interview on Home Style Green shortly!
https://itunes.apple.com/nz/podcast/home-style-green/id513213105

I would compare these guys prices to a decent Aussie or UK supplier like www.lampspecs.co.uk. You might be surprised how much cheaper LED lights are overseas, and as small and light shipping is not costly. Just ensure they have the right spec for NZ fitting tho'.

People of Christchurch! Our Energy Future Expo - Air Force Museum Christchurch. 17th 18th May 2013 www.energyaware.co.nz

Why not try this company....they definitely claim to do discounts if you order a house lot.
http://www.led-lighting-nz.co.nz/

This place looks expensive
http://store.ledwarehouse.co.nz/

Also try this place
http://www.cylex.co.nz/

Good Luck - would love to hear your experiences

Hi there

This is my first post in a forum. I am in the process of purchasing my first home. The only obvious problem with the property is that the home has an enclosed concrete/timber deck area similar to a conservatory. The roof of this area is corrugated perspex and we were informed by the real estate agent responsible for the property that the roof has no building permit.

What do we need to do to obtain a building permit? Do we need to change the construction of the roof/bearers in order to meet permit requirements? See attached photo.

I am fairly confident that the roof bearers will need to be replaced as they are not sturdy enough... Am I right?