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NZ Ecohouse Journey

This is the first post in an ongoing series that will following a Canterbury couples 'eco house' journey. Photos and more info to come.

The eco house was designed by Bill Skews -

Click here to view more images including concept drawings etc.

Part 1: The Journey Has Begun
Part 2: Sourcing Suppliers
Part 3: Wood & Water
Part 4: Slow Steps
Part 5: More Small Steps

Part 1 - The Journey Has Begun

7 March 2014

So the journey has begun. A long held dream to build an off-grid, eco friendly house is underway. My husband and I, John and Judy, are recently retired and the build will be our major project for the next year. We have lived in our present house for thirty eight years, talking for the last fifteen about undertaking this project. So we haven’t exactly rushed into it! Meanwhile, of course, solar technology and waste water systems have improved, so perhaps it’s not a bad thing. John has considerable expertise in all things practical, being a Landscape Architect, and intends to be general dog's body in the build, while I'm not sure what my contribution will be. As a teacher of English in the past, writing about it may be my biggest input! Oh, and maybe producing the nourishing lunches....

View from the building site

Our present home is adjacent to the property where we will be building and will be sold at some stage once we are well underway.

The decision to be as totally eco friendly as possible in all the choices we make in the build was not difficult. More difficult was the decision to go completely off grid, myself more cautious in this regard than John. We are not great electricity users, our last powerbill was $90 for the month and we usually add another $50 on top of that, on average, in winter. But a big ‘push’ factor towards solar energy has been the fact that getting electricity to the site would cost $20,000.

We have an early estimate of a couple of thousand less than that to get a complete solar system, large enough to power the whole house, up and running. We got this from a local solar systems engineer who has been involved in many off- grid setups. Working through our appliance wish-list with him and learning all could comfortably be accommodated, was a significant contributor to my confidence in taking this step. He was adamant that our house can be highly specced, have all mod cons (energy efficient models of course) using solar power.

As well, we owned a holiday house in the Marlborough Sounds for a number of years which was completely off grid. This used solar power for lighting, with gas cooking and fridge, and wood burner for water heating. Thus we have some experience in living without relying on electricity.

We have an idyllic location beside a large lake on family land, and a folder full of ideas which are currently being distilled into working drawings by our architect friend in preparation for the (dreaded!) building consent process.

House concept drawing

The first crucial, and compulsory, step in any building project in this part of the country (North Canterbury), thanks to the earthquakes, is to spend a significant sum on a land check. Thus our first cost has been $2500 for a geotech engineer’s assessment. This is a site specific drilling exercise which establishes whether the land will be stable in an earthquake, and identifies any potential for the soil to liquify. Liquifaction was a major contributing factor to damage in the Canterbury earthquakes.

We came through this exercise with flying colours. In fact the land was so hard they could not drill beyond 4.5 metres. We have been established to be TC1 land, the best possible category in a schedule created for Canterbury land after the earthquakes. (There are two other catagories, TC2 and TC3 which require more prescribed foundation solutions.) An engineer is currently working with our architect to oversee the appropriate foundations for our house, and we look forward to the plans being ready in the next week.

Looking South from the house site

Aerial photo of the land

This image shows a section of the 12 acres that we will be building on and the two small lakes situated on the property.

Read part 2 - 15 March 2014

Part 1: The Journey Has Begun
Part 2: Sourcing Suppliers
Part 3: Wood & Water
Part 4: Slow Steps
Part 5: More Small Steps

Part 2 - Sourcing Suppliers

15 March 2014

It will be clear to anyone looking at the photos of our building site that there is a lot of work to do in getting it cleared. This operation is planned to happen in two weeks. We have a friend who has his own business in this line of work, and will bring his large digger in to clear the building site and create a wide driveway. The site is about 200 metres from the road entrance, and while a track exists, it will need to be substantially improved. He is in need of some landscape plans so we will off-set the cost of this clearing exercise against the cost of plans John will do for him.

In the meantime, John and I went to a Renovate and Rebuild Home show in Christchurch on the weekend. We have never been people who go along to shows like this to see what the trends are, tending to buy pieces of furniture we like and stick with them until they die a natural death! However, it was an interesting exercise because we are building, and it gave us a clear sense of purpose in having a look. Such exhibitions, I can see, are a very useful way of seeing what's available without traipsing around a hundred stores.

My first observation was how widely the words 'green' and 'eco' are bandied about. Every second display seemed to feature these words prominently, even some whose products hardly fitted the term. The good thing is though that these words are obviously desirable selling points now, so that is progress of a sort, I suppose. A positive impression was created by the staff manning all the displays, they were professional, friendly and knowledgeable, so that any questions were answered in full.

Another observation was the number of companies offering a similar product, especially in the solar field. It actually became a bit confusing as we talked to each about their panels and prices, trying to establish if the quote we have for our off-grid solar energy is a fair one. In the finish John and I agreed that we feel comfortable with our chosen supplier, he isn't a big business with shop fronts and bells and whistles, but he has long experience, is very knowledgeable, and we consider him honest in his dealings with us.
He also has government awards for his work in the solar energy field. (A picture on his office (garage) wall showing him receiving one from past prime minister Helen Clarke was a confidence booster when we first met with him!)

There were also show 'specials' which appear to offer considerable discounts. To this end we were impressed with a Woodsman log burner, selling for $1999 including flue kit. It puts out 17KW of heat, enough to warm a 3 bedroom house. The log burner will be our sole source of heating, so we want to get it right, This unit is made locally which is important to us, and has two modern looking hotplate surfaces which can be used to cook on. (I visualised our morning pot of coffee simmering ....) Because we are rural, and not bound by the strict clean air restrictions of an urban area, we will have it rurally converted, which essentially means we can have greater control over the air flow, allowing us to close it down to very slow burn over night. We will also have it wet backed so that we have it as our water heating source.{ Although we are still in debate about which of solar or gas hot water we should have too, seeing as we wouldn't want to be using the log burner in summer.) The add on of these two extras will bring the price of the Woodsman to $2440. As a local hardware chain are advertising a heating expo this weekend, I intend to compare this quote with theirs to make sure it is the best possible price.

We were also able to gather good information about wooden flooring options, and compare costs with the recycled timbers we are considering. But that can a topic in the next installment.

Part 1: The Journey Has Begun
Part 2: Sourcing Suppliers
Part 3: Wood & Water
Part 4: Slow Steps
Part 5: More Small Steps

Part 3 - Wood & Water

1 April 2014

We are now getting down to the nitty gritty of build detail. The design concept has been resolved, the working drawings are all but finished and we are just waiting for the Engineer's input to be finalised. (Our fist delay, Engineers are in hot demand in Canterbury) In the meantime John has been spending a lot of time sourcing the timber for the main structural poles. Not wishing to use tanalised pine as suggested by the Architect, he has been trying to locate a more natural timber finish. Douglas fir is what we have had in our present house for the past 34 years, and all exposed beams indoor and out, are as solid as the day we built with them. All were treated with Protectoil when put up. But unfortunately there is some reluctance by the powers that be to allow this timber to be used in exposed situations.

The Engineer has suggested Larch could be an option, but sourcing this in the size and length we want is proving difficult. We have tried recycled yards and timber yards South Island wide. We are reluctant to give up on the search, however, and will keep investigating until we run out of options. It has been suggested to us by an authority in the local council that we specify the timber we would like to use (Douglas Fir, or Larch) when we submit our consent application, along with the treatment it would have and its structural elements, as well as submitting an alternative wood we know satisfies building code requirements and will thus satisfy the consent application. )

Another challenge is the water supply. Rather than putting down a well (an estimated $20K exercise) we wish to take water from the adjacent lake and filter it to remove impurities with a secondary filtration system for our potable water. We also plan to harvest rain water within the system we create. There is a lot of information on advanced filtration systems on Ecobob and elsewhere and we are working our way through these. In our rural neighbourhood there are already simple but effective filtration solutions being used by households because the well water in the area has a high concentration of iron and manganese in it.

We have decided on a company who markets a system called Aquatron to supply us with a flushing composting toilet system. It seems a simple system to install, and we have seen it operating at the marina in Havelock. The toilet looks and operates just like a 'real' one! The system separates solids and liquids, with the solids then decomposed by worms. We plan to feed the liquids through a filtering wetland before it returns to the lake.

Our grey water we also plan to treat this way and to recycle it if we can for flushing toilets etc. The mechanics of this type of system are well documented, but we will have to be absolutely convincing about the high performance of our system to get it approved by the council. The journey in this regards looks daunting. (Challenging) Any suggestions would be most welcomed.

Part 1: The Journey Has Begun
Part 2: Sourcing Suppliers
Part 3: Wood & Water
Part 4: Slow Steps
Part 5: More Small Steps

Part 4 - Slow Steps on the Journey

7 May 2014

Progress with the plans has stalled over the past few weeks due to foundation design issues. Thankfully this is back on track and the resulting revised preliminary engineering design better represents the Architects initial concept. Still looking for construction timbers that appease our desire to use untreated material but so far the search is not resulting with suitable lumber. Have been shown a supply, locally, of a cache of Kauri, Rimu and imported Oregon that we may be able to use but will have to wait to see if it is acceptable to the Architect. Due to our time frame we may have to settle for conventional materials.

The firm who carried out the Geotechnical assessment of the site wanted the main piles to be quite deep, down to solid bearing, and our Engineer was designing to their requirements. As the building is to be a light structure, our request to the Architect, I was unhappy to be breaking into the water table. So we had a meeting with the Architect and Engineer regarding my concerns and they both agreed we were moving away from the original concept. Having dug a number of post holes and planted around the property I always experienced difficulty getting a hole dug at around 3 to 400mm due to a hard silty/clay pan at this depth.

So, it was agreed that I contact the Geotechnical Engineer who carried out the Geotechnical Survey and Assessment to discuss my concerns with him. He was very accommodating and took my concerns seriously agreeing to have a relook at their requirements. The upshot has been a footing concept has been presented to us by our Engineer who has had his concepts ratified by the Geotechnical Engineer along with a couple of requirements. So we are on track with our wishes to tread as gently on the landscape as possible.

Our next hurdle will be coming up with a waste disposal system that satisfies the authorities. We have employed the services of an expert in this field, Mike Coleman from Kiwi Pioneer, who is right into organic methods of dealing with waste. As mentioned earlier, we are very keen to use an Aquatron low flush composting toilet system but will wait to hear from Kiwi Pioneer who will be sending us an options summary. We spent sometime with Mike assessing our wants, which are to be as organic as possible with the treatment of our wastes. Happy to say we are all on the same page, and I hope I can keep this so for all that will become involved with the project.

Another challenge will be a potable water supply without having to sink a well and using water taken from the adjoining lake and treating this to an acceptable standard. I have my own ideas but we may need to employ modern techniques to get the results required.

Part 1: The Journey Has Begun
Part 2: Sourcing Suppliers
Part 3: Wood & Water
Part 4: Slow Steps
Part 5: More Small Steps

Part 5 - More Small Steps

10 June 2014

Winter has set in with bone chilling mornings and short, cold clear days. Ever mindful of how we will be living this time next year, I have been aware that, even though it’s been five degree frosts in the morning, there has been good sunshine to keep solar panels charging. Very different from the late March early April weather when for three weeks it was grey, overcast and gloomy with drizzle. Panels would have needed back-up generator support for sure.

We still await the working drawings, have given architect friend a gentle nudge, but have not yet resorted to bribes! (Have a to-die-for venison casserole recipe which might do the trick….)

Our waste water planner, Mike Coleman, is carefully covering off all the potential difficulties with authorities etc, he is being extremely vigilant with the design, a good thing but a bit frustrating for John who has his heart set on a wetland type of filter drainage for the waste water. While we may have to use some conventional piping, John has asked for it to be planned in such a way that the ditch can be planted to resemble wet land. One of many compromises we may have to make along the way. The water table is the highest we have ever seen it round here, about 1.2 metres, which of course has drainage implications.

However, we have met with our builder. Andy Robson is a friend of our sons’ who has his own business, and has just finished building an off grid house in the Marlborough Sounds, one of several less usual builds he has completed. He is ‘excited’ to be doing our build, words which are music to our ears. Great to have a positive, capable builder who knows us well and understands what we want to achieve. As one of a range of lads who spent a fair amount of time on our property as a teenager, he also knows the site well, and has some happy memories of the place. It all helps with the emotional buy-in to the job. He did say that he can’t see us starting until Christmas, given where we are in the process, but we’re still hoping for an earlier beginning if possible.

We have also met with an electrician, Stewart De Joux, another one of our son’s contemporaries. He too has his own business and is willing and pleased to be involved. It was interesting to discuss the pros and cons of off grid power with him. He was of the view that bringing in power to the site wouldn’t be as expensive as we have been led to believe, but we are committed to having as light an environmental footprint as possible, and for us that means solar power.
Another small step is the announcement by the digger guy that he will be in to clear and level the building site and the drive early next week, which will mean that John can start marking out the location of garage and other out buildings. Having the site clearly defined will at least feel like progress.

Just as an aside, a friend gave us a copy of Home magazine (New Zealand Architecture, Design and Interiors), April/May 2014 edition, which shows several “homes of the year”, which are all restrained in size and construction, eco-friendly, with excellent attention to detail. Some featured ply cladding, mezzanine floors, and lots of timber finishing. It seems we may be building something trendy!

Anyway, here’s hoping we can report a great leap forward (sounds like a Chinese maxim!) in the next installment.

Showing 1 Comment

Posted by Stu Stu on 03/11/2015 03:02 PM

Query re porch rooms
Hi judy, the porch type extended rooms seem a little problematic to me. I can see the west one might be a mud room and have a door through to the main house but the northern one, which looks to be part of a kitchen, would seem to add a lot of surface area (mainly windowed), be difficult to insulate (shed or skillion roof) and block winter sun from penetrating into the house. Looks to be a similar room at the back but not sure. Why not just make the house a bit bigger and retain an efficient shape?

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