Eco-upgrade to a Christchurch home
Wednesday, July 04, 2012
The purpose of this project was to remodel and upgrade some parts of the house while at the same time improving its overall sustainability, as measured under the Green Homes Scheme, to achieve as high a Star Rating as practical.
The project was completed by David Bryce from Eco Solutions in Christchurch.
Living room North West corner and low windows to catch warm air from rock walls
Rather than a rebuild, alterations were decided on as the most sustainable option.
These include:
- Increasing insulation in the ceilings and walls and installing under floor insulation and double glazing
- Adding a thermal mass section of floor, internal rock wall and thicker gib lining to increase passive heating
- Converting a room to a solarium for food production and a source of passive solar hot air
- Relocating and upgrading the kitchen to be more functional and energy efficient
- Upgrading the wood burner and hot-water cylinder, adding a wetback heater and refining the existing solar water heater.
- Refining cross-flow and passive stack ventilation and increasing natural lighting
- Upgrading plumbing to utilise roof-water for non-potable purposes and to recycle grey water.
The alterations are designed to:
- Reduce: condensation; electric power consumption and reliance; water consumption; smoke emissions; maintenance costs; internal toxins and waste.
- Increase: food production; ventilation; comfort levels; natural lighting; safety and resistance to natural disasters; and use of sustainable products and materials.
All designers, contractors, manufacturers and suppliers were required to be conversant with sustainability principles, use appropriate techniques and processes and comply with an approved Environmental Management Plan. All products and materials were chosen as the most sustainable in the circumstances.
Emphasis was placed on proving a need for any work, minimisation of waste and re-use of any significant materials and features.
Recycled timber joinery in kitchen
Documents & design
Target: ensure all contractors apply sustainable practices, all design emphasis on sustainability and enhancing house character, guideline pay-back period 20 years for new measures.
Measures: Assessed existing building character and what parts of building could be retained and what needed to be upgraded. Specifications included sustainability measures and Environmental Code + requirement for waste management plans for all contractors. Carried out energy audit to identify heat losses and upgrading required. Carried out ALF energy analysis on final design. Carried out in-house Green Home Scheme analysis on final design. Ensured alternative/ backup systems would be available for all essential services.
Internal thermal mass site rock wall and wood burner
Dismantling
Target: minimise dismantling(avoid any demolition) and maximize reuse of materials and recycling.
Measures: reused or recycled all salvageable materials including timber, fittings, bricks, iron, doors and windows, kitchen joinery, timber flooring and walling, skirting, architraves and bench tops.
Reuse of doors, windows and new untreated timber (New Zealand Fir)
Site
Target: minimise damage to garden and re-level lawn.
Measures: relocated plants likely to be affected, avoided soil compaction by using walking planks, separate stockpiles for surplus concrete, rock, clay and soil. Layered and leveled stockpiles for native grass lawn.
Materials
Existing: 1920’s rimu timber bungalow with iron roof, lounge added 1981 in treated pine timber + concrete floor, washhouse + toilet + spa + study added in 1984 in treated pine timber + concrete floor, upstairs 3 bedrooms + bathroom/toilet added 1990 in treated pine.
Target: Ensure need, durability, versatility, non-toxicity, low embodied energy, recyclable, locally sourced, minimal environmental impact, low and efficient resource use.
Measures: removed toxic materials, replaced with eco materials, used low VOC paints, solid natural or recycled sustainably sourced timbers, wool insulation, marmoleum flooring in kitchen, part gib walls and ceilings, flax wallpaper, part wool carpet, part tiling and part varnished rimu flooring, concrete with 30% of cement substituted with flyash. Treated timber used only where required, otherwise fir, oregon or rimu.
Insulation
Existing: Some fiberglass batts in ceiling and most walls, no under floor, thermal drapes.
Target: Ceiling R5, walls R3.6, floors R2.4, sustainable materials.
Measures: eliminated draughts, extra wool batts throughout, +plywood under floor and extra wall bracing, double glazing in timber frames, + low e on solarium roof with aluminium frames. Achieved Ceiling R4.4+ply+match lining, walls R2.2+ply+13mm gib, floor R3.2+ply.Wool blankets and ply under floor
Water
Existing: Roof collection for garden, ceiling header tank, garden swales, low use.
Target: Collect and reuse all site water. Minimise use and leakages.
Measures: Ensured no water entering ground under house, repaired spouting and discharges, collecting south facing roof water in storage tank and supplying dual flush toilet cisterns and solarium water, upgraded ceiling tank to retain low pressure hot water, kitchen filter for drinking water, collecting grey water from bathrooms (and wash-house proposed) for garden irrigation(water lillee system), (propose north facing roof water for aquaculture system), (propose solar pump up to new storage tank near road), discharge storm water from hard ground surfaces to swales, low/medium flow shower and taps, hot water efficient delivery with manifold system and well insulated.
1. Polythene on ground under floor 2. Water Lillee system 3. Roof water re-use
Existing: 18 year old solar panels, short draw-off lines, h/w cylinder 27years old-no wrap.
Target: Fully renewably powered + electric backup, reduce water heat losses.
Measures: Checked and upgraded solar panel operation, installed new A grade insulated hot water cylinder, added wetback to replaced wood burner.
Water heating
Existing: 18 year old solar panels, short draw-off lines, h/w cylinder 27years old-no wrap.
Target: Fully renewably powered + electric backup, reduce water heat losses.
Measures: Checked and upgraded solar panel operation, installed new A grade insulated hot water cylinder, added wetback to replaced wood burner.
Space heating and cooling
Existing: Solar gain + old wood burner, poor heat distribution.
Target: Fully renewable heat in all main rooms.
Measures: Removed/pruned evergreen trees shading house north wall, retain deciduous vines, replaced wood burner with more efficient model (pyroclassic IV), increased glass to appropriate surface area, installed double glazing, checked eave widths, increased internal thermal mass with new concrete floor slab and tiles and thicker gib board, replaced lounge carpet with tiles on sun strike strip, added feature rock wall fireplace for extra thermal mass in living room, converted old study to solarium vented to house, installed vents above doors for better air circulation. Warm air circulates throughout house by natural convection (passive stack ventilation). Warm air from outside rock wall vented inside through low windows. Minimal windows on south wall to introduce cool air on hot summer days.
1. Thermal mass suspended concrete floor with tiles for solar heat storage 2. High level windows for passive heat circulation 3. Solarium at North East corner
Ventilation and air quality
Existing: Natural, passive.
Target: Adequate air exchange and dehumidifying.
Measures: Extractor fans installed for kitchen and bathroom, cross- flow opening windows, reduced carpet areas, minimise synthetic materials.
Cross-flow ventilation
Washing/drying
Existing: Sewer discharge, outdoor clothes line, internal fireside airing and electric dryer.
Target: Water reuse and natural drying.
Measures: Washing with ecoballs and discharge to garden, outdoor clothes line and internal fireside airer.
Lighting
Existing: Compact fluorescent, some during daytime.
Target: Natural daytime light, necessary night-time energy efficient lights.
Measures: Extra windows, solar tubes in toilet & bathroom, LED efficient lighting.
More Photographs
Thermal mass suspended concrete floor with tiles for solar heat storage
High level windows for passive heat circulation
Solar water heating panels and low-emission wood burner flue
Solarium at North East corner
The project was completed by David Bryce from Eco Solutions in Christchurch.
Your comments:
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by Ecobob.co.nz
5 Jul 12,
22 replies :
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290 posts
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Eco upgrade to a Christchurch home
Posted 5 Jul 12 1:45 AM
Post your comments on this article here.
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91 posts
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Re: Eco upgrade to a Christchurch home
Posted 5 Jul 12 3:45 PM
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
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42 posts
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Re: Eco upgrade to a Christchurch home
Posted 9 Jul 12 8:49 AM
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491 posts
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Re: Eco upgrade to a Christchurch home
Posted 9 Jul 12 9:26 AM
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.
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42 posts
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Re: Eco upgrade to a Christchurch home
Posted 10 Jul 12 9:45 AM
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.
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292 posts
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Re: Eco upgrade to a Christchurch home
Posted 10 Jul 12 6:58 PM
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).
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Re: Eco upgrade to a Christchurch home
Posted 10 Jul 12 8:43 PM
I agree Seeker. Perhaps the rating could be more heavily weighted towards the infrastructure.
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5 posts
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Re: Eco upgrade to a Christchurch home
Posted 15 Jul 12 12:27 PM
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.
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491 posts
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Re: Eco upgrade to a Christchurch home
Posted 15 Jul 12 5:43 PM
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.
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42 posts
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Re: Eco upgrade to a Christchurch home
Posted 16 Jul 12 9:49 AM
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. |
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491 posts
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Re: Eco upgrade to a Christchurch home
Posted 16 Jul 12 10:30 AM
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.
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4 posts
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Re: Eco upgrade to a Christchurch home
Posted 17 Jul 12 3:29 PM
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.
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4 posts
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Re: Eco upgrade to a Christchurch home
Posted 17 Jul 12 3:39 PM
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.
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491 posts
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Re: Eco upgrade to a Christchurch home
Posted 17 Jul 12 3:43 PM
Wow if this gets 7 "stars" my passive house will have 12 or so :-))
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4 posts
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Re: Eco upgrade to a Christchurch home
Posted 17 Jul 12 4:01 PM
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
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150 posts
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Re: Eco upgrade to a Christchurch home
Posted 18 Jul 12 10:37 AM
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??
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80 posts
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Re: Eco upgrade to a Christchurch home
Posted 18 Jul 12 11:37 AM
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?
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491 posts
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Re: Eco upgrade to a Christchurch home
Posted 18 Jul 12 1:20 PM
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
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1 posts
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Re: Eco upgrade to a Christchurch home
Posted 1 Oct 12 7:05 PM
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
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4 posts
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Re: Eco upgrade to a Christchurch home
Posted 1 Oct 12 8:26 PM
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
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42 posts
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Re: Eco upgrade to a Christchurch home
Posted 1 Oct 12 8:59 PM
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.
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Re: Eco upgrade to a Christchurch home
Posted 26 Nov 12 8:13 AM
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.
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2 posts
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Re: Eco upgrade to a Christchurch home
Posted 27 Nov 12 9:10 PM
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