Saturday 28 March 2020

Summers finished and so has the tramping ... Lockdown has put an end to that!

This summer saw us get out for a few trips, there is never enough time to do everything!
But I am grateful for the trips I did get in and the people I shared them with, Helen, Karen and Dean.

Our first foray into the hills was an old favourite in Nelson Lakes National Park, the Bushline Hut, this has one of the best sunrises and is so worth getting up for.

Just over an hour and a halves drive and roughly two hours walk from the road end, this beaut little hut resides nuggled into a piece of native busk looking down on Lake Rotoroa and St Arnaud village.







Our next trip was in Kahurangi National Park to Mt Owen, I don't know how many times I have driven by and looked at the Mt Owen massif yet never been up to it.

Again with the company of Helen, Karen and Dean we drove to Tapawera and into the Wangapeka carpark to spend the day climbing through the bush and out onto the tops to Granity Pass Hut, to spend the night and return the same way.
The rock formations are stunning and it is well worth the effort to get to, certainly I will be going back.





Our third trip before the Lockdown was five days into Kahurangi National Park again to the Thousand Acre Plateau, this is an absolutely stunning place to visit, we were fortunate to have fine weather for the length of our stay with minimal contact with others it certainly felt like a wilderness trip.
With three nights in huts and another in the tent Helen and I took our time to explore and relax.








Until next summer post lockdown!

Living off the Grid


It has now been twelve months since we moved into our house and began living off the grid.
For us interesting has been a year of learning …

But first what is OFF THE GRID?

For us it means we are not connected to the National electrical power supply network, so we don’t draw our power from the Dams, Gas, Geothermal or Coal fired power stations. In effect we are our own power station. (just about).

We are still connected to the Town water supply, storm water and sewer system.

Why?
Mainly to reduce of carbon emissions footprint and have some control on the power prices. Ever noticed how power prices keep going up?

What makes up our system?

We have 12 photovoltaic panels on our roof (each 270 W, totals 3.24 kW), these convert sunlight to electricity in our case on average they will produce between 5 and 7 Kilowatt hours (kwh) per day.

These face directly North, and are set at a tilt angle of 51° to maximise the sun during winter hours when the day is shorter. see picture below from the NIWA Solarview website



These are feed into an inverter which does two things, if we are drawing power within the house at the time it converts the electricity from DC to AC and sends it to the house. Any surplus stays as DC and goes into the battery bank to use at a later time. Then it goes back through the inverter and converts it to AC. Simple!

The battery bank is made up of 24 batteries (600 amp hours (Ahr)) which gives 3 to 4 days of power storage. If we have to weather of storm longer than that we have 6 kilovolt (kV) petrol generator, that we can charge the batteries up with, this I have been told would take approximately one hour.

Battery bank in the garage with the Inverter next to it (redbox)

Our hot water cylinder (250 litres) is heated by 20 solar evacuated tubes, these very good at heating the hot water at around 90 to 95% efficient. Whereas a PV panel is only between 20 to 25% efficient at converting sun to power. The cylinder can be boosted with gas. It has also been wired for electrical supply, if we ever expand our number of PV panels.


Evacuated solar tubes at rear and the PV panels at the front

Nearly everything in the house is electrical, with the exception of the following we have (as mentioned) gas boost to the hot water and a gas hob and oven.

The house looks like any other on the street inside or outside.

Did it work? How has it gone?

In the short answer yes and well.

In some detail …
Hot water was boosted on 51 days, that means 314 days of fee hot water.

From the 6th of May when I started to record power use to yesterday (27th March) we have used 1450.24 kWh or 4.44 per day. This is within the plan production of power from our system.

Generator use has been limited to giving it a service run every three months to make sure it starts and its battery sis still charged. On two occasion, as we have used when using larger machinery, once was a concrete mixer and the second while using a large sander and vaccum at the same time. This demonstrates how small our system is.

Our smallest power use day has been 1.7 kWh, this was while we were on holiday and did not have anyone staying in the house so was basically just running the fridge/freezer and inverter, and our largest has been 7.42 kWh.

Nine of the twelve PV panels visible, there is another row of three sitting behind the row of six


What did we have to change to make this work?

This was the interesting part, it was a matter of changing habits more than anything
  •         Turning lights off as you leave a room
  •          Turning appliances off at the wall when you have finished using them
  •          Not using the dishwasher and washing machine at the same time.
  •          In summer we can use the washing machine and dishwasher on the same day but needs to be alternative days in winter
  •          Using the dishwasher and or washing machine mid-morning in winter as that time for the power storage to be built back up in the afternoon.
  •          Sometimes having to leave the dishes or washing to be done on the next sunny day (generally a storm cycle in Nelson is about three days).
  •          We use a slow cooker on sunny days when we want a casserole or roast
  •          Up until December we did not have a toaster or electrical kettle, since buying them power consumption has gone up between 0.75 and 1 kwh a day. We may be able to use them for 8 to 9 months of the year, reverting to using gas for these tasks.

How did it effect our emissions footprint?

Comparing the 12 months previous it looks like this

2018-2019
2019-2020
Power
185.1
0
Gas
57.9
206.5
Petrol Genie
0
12.5
Total kgCO2e
243
219


A 10% reduction, the key to further reductions will be using less gas … there is always something to work on and this is a start.

How much did it cost to run the house for the last twelve months?
Gas          $138.00
Petrol       $  10.00

Now if we can just get that gas volume down!

Sunday 8 March 2020

The House which Helen and Brett Built


For years Helen and I had discussed small houses, tiny houses, sustainable houses, eco houses, etc. Finally after giving up on searching for a house a. we could afford, b. one which fitted our requirements or had potential to fit our requirements. A piece of land came up which had some potential.

The block of land was a back section with the building platform cut in and retaining wall in place, it faced east and north, it was close enough to Helen’s work, could not be built out, it had potential if we were smart with our design.
It did not take long to decide to buy.

That was January 2017. Now it was time to work out what fitted and what we required …
After twenty years on the tools as a builder, I had built on hillsides, seen a lot of ideas, some that worked and some that hadn’t, seen the amount of waste that occurs during the building process and seen how houses had just got bigger and bigger.

Design Concepts
Our design concept was easy to narrow down … the first three points were non negotiable …
  • ·         It had to be off the grid powered
  • ·         It had to be warm
  • ·         It had to minimise waste


The next few points had some flexibility to them ...
  • ·         Two bedrooms
  • ·         One bathroom
  • ·         Large garage
  • ·         Easily maintained
  • ·         Easy accessed for worn out and abused bodies after too much adventuring
  • ·         It had to be small but not tiny
  • ·         Good storage
  • ·         No wasted space

The concepts of size and volume combined with how they feel in terms of spaciousness is often hard to pick up from drawings, so we spent time measuring rooms and discussing how they felt.

Finally, we came up with a sketch plan that we thought would work, then it was a matter of what materials to use ... we researched Structurally Insulated Panels (SIP’s), the marketing is all about extra insulation and speed of building, while I had seen one in-person and liked the concept, there seems to be a few minuses.

There are two types ... one is filled with polystyrene, the second is filled with polyurathane (PUR) foam. Talking with a builder who had used the polystyrene ones, commented that the site ends up covered with polystyrene beads. Also at the time I was researching these ... they were all imported from either North America or China ... that's a lot of travel miles for a product. I found a company in Central Otago who was making their own PUR panels, but the more we looked into using SIP’s the more expensive it became, due to them requiring to be a Specified Engineer Design (SED), as they fell outside NZS3604. While they came with plywood or strandboard on either side, you still needed to line both sides, often requiring to create some sort of cavity on the internal side to run the electrics and plumbing in. These were costs which we could not afford so it was back to the drawing board.  In the end we choose traditional stick framing.

Our Architectural Designer, Jade, bless her paitence, reworked her drawings for us.

While this was all going on, I worked out what power we had used during the last three years, and chased up people to quote for a solar system design and build. As this was a non negotiable, the figure was taken out of our total build price and what the balance was left was what we had to build the house with.

Solar Power and Hot Water
The solar power system is required to supply 5 to 7 kWh per day, it has a 600Ah battery bank which gives about 3 to 4 days power storage, this is in turn backed up with a 6kW petrol generator.
The seperate Solar Hot Water system, is a 250 litre hot water cylinder fed by a 20 solar tube roof mounted system. This is backed up with an instant gas hot water heater.

The hot water cylinder does have the ability to be heated electrically and the house has been pre-wired for this.

What do we have in the house which requires power or heating?

Electrically, most modern appliances with the exception of a microwave, toaster and kettle. The oven and hobbs are gas. The house is heated with a Masport Cromwell Ultra Low Emission Burner (ULEB) log burner, no wet back. All the lights are LED.

Since January we have added a toaster and, kettle back into the equation and this has bumped our daily power usage up so ever slightly. This will help reduce the amount of gas we would use, while it may only be for eight months of the year it is still a reduction.

Has it taken much to adjust to solar power and a limited supply?

Not really, it was just a matter of changing some lazy habits ... turning lights off when you leave a room, turning appliances off when you have finished using them.
Plan to use the dish washer and or washing machine on sunny days and during the day, when power is being created, learn to use the slow cooker for meals and baking on sunny days ... the gas oven on grey days. We try to minimise the gas used.

How has that worked over winter (June/July/August)?
During our first winter the power use has average 4.5 kWh per day, no use of the generator. The hotwater 41 days on gas and 50 days on solar, with 91 days of log burner use.

Over the last 11 months we average 4.99 kWh power useage per day.

Back to the design ... Waste Minimisation

Waste minimisation ... house builds in New Zealand create large amounts of waste, somewhere between 12 and 18 m3 on an average sized home.
This is partly because most designs are unique, lots of corners, multi faceted pitched roofs, complex shapes. Not only does waste cost money, it also costs extra in time, resulting in a higher price per square metre.

While our design is not just a box, it is still simple, trying to minimise the number of corners, the roof is single pitch, our kitchen, bathroom and laundry all back onto each other minimising the length the pipe work has to run and the volume of hot water wasted.

Discussion were had with each Trade about minimising their waste, asking them to take time to think about what they were doing and how that would effect the “philosphy” of the build, all were considerate.

In the end we sorted out the likes of cardboard, plastic and polystyrene to be recycled, leaving 7.25 m3 of mixed waste to go to the rubbish station. Could we do better ... definitely! It would only take some minor tweaks to get that down more.

 How warm is the house?

The concrete slab is a Firth Rib Raft with insulated edges R2.3 (minimum required R1.3).  To prevent heat leakage, the walls are 145mm thick and have R4 (minimum required R2) insulation, and the ceiling has R5 (minimum required R3.3) insulation.

The windows are double glazed R0.26.  These are not thermally broken, the reason being it was going to cost an additional $4000 to lift the window R-value from R 0.26 to R0.3?.  That gain was so minimal, it was better to make the external framing 145 mm deep rather than 90 mm and up grade the insulation from R2.6 to R4.0 for the same price.

The logburner easily heats the whole house to 22 degrees and without curtains over winter it has dropped to 16 degrees in the morning. Which we find is comfortable.

During low winter sun, the early morning sun reaches in and to the back wall of the kitchen warming the house up very quickly!

So we achieved our three non-negotiables with surprising ease and we love that fact.

What other features have we included?

The house is 100m2 and the garage is 38m2.  The average size home in 1900 was 131 m2 in 2010 it was 205 m2, oh and families have got smaller!



















It is two bedroom, one bathroom, all the doorways are 910 mm wide allowing easy access for a wheelchair, there are ramps to the front door and off the deck or through the internal access garage, only the back door currently has steps.

With having single pitched roofs, four degrees over the house and ten degrees over the garage, we maintained the same with the ceilings internally, this gives us a nice spacious feeling to what would be consider smallish rooms, it has also allowed us on the eastern and northern aspects to have windows and doors 2.3 metres high, adding to that spacious feeling.

We have created some natural air conditioning, the back of the house (office and bathroom) are in the shade for most of the day which mean the air is cooler there, the windows in theses rooms open mid way up the wall, while at the front of the house the windows open at the top, with having a sloping ceiling the hot air rises to the front of the house and exits, this pulls cooler air in from the rear of the house. Sounded good in theory and actually works.
We also have ceiling fans which are DC motors, they only draw 40 watts to operate, these help circulate the air in winter and summer.

In the garage that has allowed us to have a 1.1 metre wide, shelf six metres long above head height for storage, and a retractable dry rack.

Trying to not have wasted floor area in a house is not easy.  Hallways are often one area that only have one use ... we tried to make sure we could make use of every area, our hall is only 1.8 m long.

Maintenance

The house is easily and cheaply maintained, the roof and west and south elevations are colourcoated long run corrugated iron, these only need to be washed down regularly. The east and north elevation are macrocarpa weatherboard, which are easily and safely accessed from a small mobile scaffold for restaining. 
The soffits are painted and also easily accessed by a small mobile scaffold.
Around the back where the stormwater and sewer pipes are laid, we have put a floating deck, this can be lifted in sections for access to the pipes, rather than a concrete path, which is more intensive to remove and replace if there is an issue with the pipes.

Materials

The choice of products is not easy and like the design is always full of compromises. We tried to use local products firstly from Tasman ... like the Macrocarpa weatherboards, and Tasmanian Oak decking, which was grown and milled here, to New Zealand grown and manufactured products, to products that were fully or partially recycled in their content.

We use the Macrocarpa with a band sawn face, on the weatherboards and also for the skirting and architraves, this has a reel texture about it and helps create the feel in the house.
The weatherboards are not perfect and have lots of character, this contrasts with most modern materials which I find just a bit too perfect.

Our kitchen bench top is plywood, initially it was only to be temporary, but it has grown on us …

Internally, the walls are painted, all finishes were low VOC and waterbased.

The carpet is New Zealand wool and we have some ceramic tiling in front of some doors, the tiles help to create a heat sink to store heat which releases as the temperature drops.
Our entrances, kitchen and bathroom floor we have a used a floating solid bamboo product. Bamboo grows at one inch a day more like a weed but is hard wearing and sustainable.

The house build

This went relatively smoothly without any major hick ups and the only real delay was with the windows due to the company over committing their production resources, the costs of this does add up, as we left the site for a fortnight ... extra rent for two weeks, extra mortgage repayments, extra hire time on the scaffolding, extra project management time in rescheduling other suppliers and trades. The smaller the build the bigger the impact percentage wise.

Subtrades on the whole were good, they stuck to their quotes and time frames, advised us of any variations. 
The exception being the Electrician who in the end lacked business and communication skills and understanding of Building Laws.
Thanks to
Jade Architecture - Design
Chris Barnett Construction – Ribraft floor
Warren Burgess – Carpenter and good bugger
Allen Plumbing – Plumbing, Gas Fitting and Drain laying
Solar Peak – Solar Hot Water
Go Scaffold
MBE Electrical – Solar Power System
Mitre 10
Contour – Roof and Wall cladding, windows and garage door
Totally Timber – Macrocarpa and Tasmanian Oak
ET Engineering – Structural Steel Posts
Duke and Cooke – Valuers
Tasman Consulting Engineers
TSB - banking

Also to
Rick and Trudi for feeding us at least once a week, Luke for his technical support, Jacqui G for her cakes and all our friends and families for supporting us.

The house has exceeded our expectations, it was great to take four months off to build this home and to put a number of different concepts to the test.

Finally to my best friend and fellow adventure buddy, Helen, for getting on the tools learning new skills, trusting me with so much, putting up with me being so tired and grumpy, working full time at the hospital then spending her days off working on the house. THANK YOU for your love and support.

Oh yeah ... it came in about $5k (2%) over budget, but we do have a couple of items that were not in the orignal budget ... a small garden shed and wood shed and approximately 47 m2 of hardwood decking. With the final build cost being just over $1800 per square metre.

Helen’s report on Brett and Helen’s home. 

I’ve spent years Nursing patients in differing environments, people of all shapes and sizes, from all sorts of backgrounds.  And overtime I’ve become acutely aware of the environment in which we live impacts on us all.  If we can look after our physical environment, we can be healthier individuals – loosely put as we know there are so many variables to the state of our health in the end.

So my focus of late has been to try to look after our physical environment better, and this is a focus I was keen to have for our home.  We had been looking to purchase our own home for a while.  The radius was large, out to Tasman and Wakefield, and to Cable Bay.  Old and new homes, and building sites.  There was alot chewed on, we did put an offer on a piece of land out at Wakefield, but I realised being able to push bike to work was important to me, and when we realised the sellers still had developers fees to pay which were being passed on, it was an easy out. 

We came to a point where we stopped looking, stopped visiting open homes.  Then one day an email came through on homes and pieces of land for sale, and there was a piece of land that just seemed to get the taste buds going.  And the rest is history – it was an easy decision, with the building platform already cut with a retaining wall in place, and did I mention the view, oh its terrible, not!

A back section we soon purchased, and the nights awake began, mulling over the build concept.  A small home is all I wanted, I couldn’t see the need for a large home, at the end of the day its the mortgage we’re working for, the maintenance and the power to heat.  I wanted as small a mortgage as possible, extra insulation to keep us warm when we’re older.  I also was keen for an off the grid home, powered by the free resource of the sun, and in keeping with taking care of our environment, I was keen on low amount of waste made during the build. 

With plenty of visits to the site, and time spent literally inside our design, we eventually came up with a plan to present to our Design Architect.  I can’t quite remember the rest of the process, somehow we came up with a design which got approval from Council, and on Brett’s birthday, end of October, the first pieces of earth were moved as the build finally got underway.
 
While Nelson experienced a drought over summer, we hammered away, feeling slightly better about not getting any mountain biking done over summer, the tracks were closed anyway. 
I had never been exposed to building a house before.  In hindsight maybe some months of gym workouts to prepared myself to use a nail gun would have been, ah, beneficial!  And also to have researched the process of steps a house undergoes to take shape.  Not having been in the position of learning like that for a long time was pretty bloody hard, especially with the rate that Brett works.  

Poor buggar, all those questions! 








After 5 months of slog we finally moved into our home.  It was fully enclosed, but still needed alot of work done.  Now 5 months on there is all but a handful of small jobs needed completing. 

I was really pleased with the small amount of waste produced from our build.  But have some reservations about using natural gas for our oven, and back up for hot water.   Being pretty conscious about the impacts we have on our environment, and burning gas I struggle with, this was for me an oversight in the planning of the build.  Without trying to justify, by living we are compromising our earth, I’ll just keep peddling to work.  How would I do it differently to natural gas if there was a next time – I’m really not sure, maybe more solar panels to create more electricity, but then there is an end life to everything including solar panels.


The position of our land has a north and eastern view, out to Boulder Bank, north of Nelson, and east to Fringed hill and the mountain bike tracks calling our names.  

Immediately below us is a regenerating gully, and the bird life coming from it is special.  We watch birds entwined in their intimate mating dance, those out hunting, and those catching insects on the wing.  I’ve been busy planting native plants kindly donated from friends, which will one day feed more native birds.  And I’m in the middle of creating some raised vege gardens. 

Our home has exceeded our expectations.  The view changes with the weather and the light from the time of day.  Our fire keeps us and the cats warm at night.  And the space we have created just feels right, and well thought out. 


The help and support we have had throughout the build has been appreciated, thanks Trudi and Rick for feeding us, and telling Brett to have the odd day off!  And to Jacqui G for the cakes, yum!  It was a hard slog, but nothing comes with sitting around.  And thanks to Brett for the love and support to keep going.