Topic: Eco upgrade to a Christchurch home

Eco upgrade to a Christchurch home 

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Re: Eco upgrade to a Christchurch home 

From all that I read, the changes seem significant; this is very encouraging in NZ and for Christchurch. What I cannot find in the article is how many energy stars does the project hope to achieve? Leo

Re: Eco upgrade to a Christchurch home 

What was the ALF score?

Would be great to get a homestar rating done. It sounds like with all the evidence you've collected, and the attention to detail, you'd achieve a good rating.

http://homestar.org.nz/assessment-types/homestar-assessment

Re: Eco upgrade to a Christchurch home 

While it is great too see projects like this, the sad side is that while this existing house was upgraded hundreds or some thousand of new substandard houses were built across the country.
Things will never change unless the building envelope part of the building code gets an overhaul by people who do actually have an understanding of physics.

I had a conversation with someone from homestar at the last build nz. It sounded all good until I noticed that this people are not recommending the best performing products available but the ones of their "gold", "silver and whatever sponsors.
Most of them took part in providing us with world class energy efficient, comfortable and healthy housing over the last 30 or 40 years.

Re: Eco upgrade to a Christchurch home 

Totally agree that the building code, in the current form, doesn't lead to well performing homes.

Homestar will provide an overall environmental rating. The online tool does provide some generic recommendations but these recommendations are independent of specific products.

The overall objective is to bring up the standard of the New Zealand housing stock.

Re: Eco upgrade to a Christchurch home 

I have been a bit jaundiced about the Homestar scheme, because for me the critical thing is the housing insfrastructure itself.

The Homestar rating includes non-infrastructure items - I firmly believe that the really hard things such as thermal mass or in-wall insulation need to have their own "rating" that is separate from the "do-able later" type things (like rain water harvesting).

Re: Eco upgrade to a Christchurch home 

I agree Seeker. Perhaps the rating could be more heavily weighted towards the infrastructure.

Re: Eco upgrade to a Christchurch home 

If you want to get a certified Homestar rating done I can possibly help you with that as I am a Homestar Assessor or one of the other assessors could do it. There are a handful of them now in canterbury listed on the Homestar website. Regards the comment below - Homestar does actually have a heavy weighting on the thermally efficiency / thermal envelope (almost half) with 46 out of 100 points for the energy, health and comfort section.

Re: Eco upgrade to a Christchurch home 

The homestar rating has a limited use for the homebuyer because it is mixing up two different things.
One is the the permanent performance of the building and the other tangable things like recycling or curtains or appliances.
The second one is meaningless for a home buyer.
In Europe there is no star rating as such but performance is given as anual energy use per m2 and minimum requirements for each component of the thermal envelope. E.g you cannot compensate non insulated window frames or single glazing or poor insulation in the wall with super thick insulation in the ceiling or curtains.
This is more accurate and truthful than stars but against the commercial interests of the "homestar" sponsors (e.g. Fletcher Aluminium) who don't want their substandard products and low standard building practice identified as total underachivers and failure points in the thermal envelope.

Re: Eco upgrade to a Christchurch home 

Guess what? I think that's a really useful distinction you make between the permanent structure, and removable (and movable) items.

Homestar definitely puts more weight on the permanent structure. There is a question about thermal curtains in the online, self assessment (http://homestar.org.nz/properties), however this is mainly for educational purposes and to encourage people to think about how curtains can affect comfort as well as aesthetics.

The tool also asks about some of the more significant appliances, for example the main refrigerator, washing machine and dishwasher.

There is definitely a recognition that human behaviour is going to play a big part in how much it costs to run a home and how healthy the home is. An aim of Homestar though is to provide a guide as to how well a given house can perform and it was decided that the efficiency of some of the more significant appliances should therefore be included.

Re: Eco upgrade to a Christchurch home 

But it does not clearly identify whether the entire building envelope is up to a reasonable standard or not ???.
Walls, ceiling, floors all insulated including corners, window frames reasonable thermally efficient or the glazing. As a home buyer I know my part of possible savings which I can make with appliances and how I live. What the home buyer needs to know is the performance of the actual building which is there no matter who lives in it.

Re: Eco upgrade to a Christchurch home 

Sorry for delay Leo. We can't do a full assessment yet because connecting rooms have yet to be upgraded. I've done a "self assessment" on the hypothetical completed project which is 6 star, but we hope to get that up to 7. Dave.

Re: Eco upgrade to a Christchurch home 

Sorry for delay. I agree with your concerns and drew up my own "sustainability criteria" and also used "envirospec" to check out some products. It's a pity we can't get a fully independent system. Dave.

Re: Eco upgrade to a Christchurch home 

Wow if this gets 7 "stars" my passive house will have 12 or so :-))

Re: Eco upgrade to a Christchurch home 

Sorry for delay. I have used the earlier versions of assessment criteria and the current version is certainly a big improvement. However there are still curious and unclear questions and it would be good to see a revision some time. eg what is the relevance of Q7 "Are you considering installing a new hot water system any time soon?" also Q5 asks "What is the MAIN type of space heater in the house" while the penultimate option states..."comfortable winter-time temperatures...provided SOLELY by the sun". Dave

Re: Eco upgrade to a Christchurch home 

I trained up for the stillborn HERS (accurate) scheme.
Then I trained up for Homestar.
I've never sat the final exams for either as I thought both were a crock. My fellow trainees all walked out at the end of the homestar training session shaking our heads in frustration at the ridiculous criteria they incorporated into it.
HERS was way too complicated for the average house.
Homestar is way too dumb for any innovative house.
We need a rating system that stars out really easy for modest houses but ramps up the criteria and measurements for high ratings.
Passivhaus criteria are the obvious ones to shoot for at the top end, they have never been mentioned in HERS or Homestar, maybe they've never heard of them??

Re: Eco upgrade to a Christchurch home 

My house rates a 5 on Homestar, 'below average'.. which makes me laugh (sadly). Interesting given that the lowest the internal temperature has dropped to this winter is 17 degrees (down from 21 when we went to bed the night before), and with an outside temperature of 3. I also consider our dramatically above code EQ strengthening fairly important, but not so Homestar it seems.

But then I guess we don't have a greywater system, rain barrels, use self generated power and live within 10km of a marae, bank and fitness centre.. so what would I know?

Re: Eco upgrade to a Christchurch home 

Samiam,

Homestar, HERS, WERS or whatever are mostly designed to greenwash poor building practice, design, components such as aluminium windows and low standard thermal envelopes.

WERS for example assumes quite low R-values for uPVC and timber windows compared to aluminium.
Why do they do it? Because the real R-values of uPVC and IV 68 windows would make any NZ designed aluminium window (tb or not) look like a big big JOKE.

Or glass, their charts don't even show anything near ug 1.1 (DG), Ug 0.5/0.7 (TG)which is state of mainstream technology. Why? because the DG manufacturers have to lift their standards.
Tasman Glass is now onto it.
Overall the WERS rating is not accurate. Uw, Ug and Uf figures tell much more the truth than stars, but it can't be again it is too embarrassing for the aluminium window companies like Fletcher

Re: Eco upgrade to a Christchurch home 

I'm trying to make my new build passive but council regulations mean it has to be mobile and the builder says this means I can't have a concrete slab. Is a concrete suspended floor economically feasible? How thick is it? And how did you incorporate that with the wood floor? Does anyone know how I might best increase the thermal mass on the floor? Spence

Re: Eco upgrade to a Christchurch home 

Not sure what you mean by "mobile". Our existing old floor was about 1.5m above ground. The slab is max 180mm thick(with 30% of the cement substituted with flyash to reduce carbon emissions), supported by concrete foundations and walls around perimeter, poured on "Diamond Hi-bond" steel tray. Tiles on top match level of t&g flooring on piles adjoining. You'll need to calculate how much thermal mass is required. A solid internal wall getting the sun also an option. Check with an eco-architect. Dave

Re: Eco upgrade to a Christchurch home 

Dave, sorry I missed this ongoing conversation. How's the upgrade going? As Bob says, you should be able to get a Homestar Practitioner to look at your plans with the more comprehensive certified tool. They can do this before your build is completed.

Re: Eco upgrade to a Christchurch home 

Hi All,
First of all, David congratulations on a great upgrade!

I agree this could fetch a good Homestar rating, so may be worth considering.

For all the others who have made comments about Homestar, I hope you have undertaken the full Homestar Practitioner or Assessor training and have reviewed the Technical Manual in depth before posting anything? Please note the Homestar public website and Homecoach training is more of an educational tool for "beginners" in the industry, so to speak.

The Homestar certified tool does look into important base structure items such as thermal mass, insulation ,etc. It also looks into much more than that...and even goes as far as social sustainability and future proofing for disability (i.e. can a person a wheel live well in the home, etc).

As for the idea of separating out just the energy component, this could indeed provided some useful feedback... in which case it is possible to segrerate out just the EHC6 part of the tool (i.e. the "Whole of House Thermal Performance Calculator"), which will provide a good indication of the property's energy performance (inc KWhr energy requirements) without being as complicated as HERS (although admitedly therefore not quite as comprehensive).

Hope this helps.

Re: Eco upgrade to a Christchurch home