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The Design
Tina has been a designer with an interest in passive solar design and eco design in general for more than 20 years and attended the first Green Home workshop series held in 2007.
She designed this Scandinavian fully scribed log cabin for her parents, Jan and John, who moved in August 2009 after two years of building and nine years of planning. The house was more expensive to build than a similarly sized conventional house, mainly due to the labour intensive nature of the work.
Keeping with the traditional look and way of building was important to all. This traditional ‘full scribe’ style of log cabin building is where each log is placed one at a time and cut to fit the next log being placed on top and the round log is visible inside and out. Many log cabins are contemporary on the inside by using a cut log, rather than the whole log.
A key part of the design was getting the proportion of the rooms, windows and doors, and roof right to accommodate the size of the logs. Extra space was needed inside the house to avoid a claustrophobic effect.
Jan describes the house as being big, spacious, warm, and comfortable. The logs are a thermal mass – absorb and store heat during the day and release it at night. The passive solar design works very well. The house is also cool in summer with great cross ventilation. John adds that log cabins are timeless, need little maintenance and are so solidly built that they last and last generations.
Building for Future Generations
The building of this home was a real family affair – Jan had always wanted a log cabin and did all the research required, John put his milling skills to work to prepare the logs, and Tina did the design and calculations to make the house ‘work’, with others helping out and overseeing on occasion.
The setting is a large part of the appeal of the property. A creek runs through the 13 acre site, which also has a pond. Now that it is built, this home has become a big extended family focus with camping, swimming, kayaking and fishing providing endless fun for all the grandkids. It is John and Jan’s desire to leave the home in perpetuity as a legacy for their grandchildren for generations to come.
Structure is Finish
Essentially the house was built from four natural products: lawsoniana for the structure, old pine trees for the roof shingles, macrocarpa for the windows and doors, and Otago schist for the fireplaces.
Tina is a strong believer in ‘structure is finish’ – by limiting the number of materials and utilizing resources in their natural form results in a clean, minimal build, with little or no off-gassing.
Jan and John have worked in the milling industry so they had the advantage of not only having all the gear and skills they needed to mill the trees but also the contacts to source the wood, such as the clean macrocarpa needed for doors and windows and the old pine trees needed for the roof shingles. Both are proud of the fact that they have handled every single piece of timber that has gone into the home.
The Logs
Lawson Cypress Chamaecyparis lawsoniana is a native of the lush rainforests of southwest Oregon and northwest California, where it can grow to a height of 54 meters. It is known in New Zealand as Lawsoniana and it has dark green fern like foliage which give off a strong aromatic smell. Like the macrocarpa it holds on to its leaves and shows little sign of drooping.
The land they built on they had had for five years. Once the land was leveled they knew they needed to find a sufficient lot of trees to build with. They found two hedgerows of Lawson cypress 80 year old trees in the Aria area. A fun little piece of history was that the trees were used as the first drive in movie screen in the 1930’s.
This lot of Lawsoniana was chosen as it was the most readily available, its durability and ease to work with, as well as having a good span distance for cabin logs. However it also turned out to be a good source to build the log cabin from as it becomes more toxic to insects and bugs the dryer it gets and it is weather resistant. The age of the logs were also important – the older the better, with heartwood the best.
Preparation
An important part of the planning process when working with natural forms of wood is to think ahead about what will be needed for the build. Add a couple of years drying time. Macrocarpa needs drying. When it is ordered, it will be milled and delivered but it will need storing to dry it.
So once the 185 tonnes of trees were sourced and a deal was struck, they were, felled, trucked to the site, peeled, planed and then stacked to dry while sorting out the build. The dryer the logs are the less shrinkage there is when they are put into place. Logs also need to be sealed to ensure mould does not turn the logs black.
While they were drying the family sorted out the design and consents. Everything had engineering approval and the building code was signed off and consent gained before the build started.
Another positive aspect of this build taking so long, meaning that the wood was dry when going up, was to ensure that light switches were secure as these can’t be changed once they are in and it is discovered that the wood is moving, and can cut the wires.
Construction
Once the logs had all been peeled, stacked and dried, the guys who constructed it came onto the scene. Edwin and Amos from New Zealand LOGHOMES are based in Rotorua and trained in Canada.
It took them a year to assemble and scribe the logs for the house in their warehouse, then number each log, then disassemble it and finally deliver it back to the site for reassembling on the foundations, which were built with a minimal amount of cement.
Insulation
The ceiling sarking is 4x2 with ply to weatherproof the build, and then insulated with batts, but was designed before the new Building Code requirements which means it may not have the prescribed level on insulation in the new Building Code.
The Roof
Authentic log cabin houses are built with roof shingles. In keeping with their desire to build a traditional log cabin 25,000 roof shingles were quarter sawn from tanalised old pine trees. Using tanalised shingles would limit future water collection to garden use only.
The normal roof additions are kept off the roof, to ensure there were no cuts in the roofing and shingles that would let a leak. Finding a leak is impossible once one starts, so minimizing the chance of a leak occurring is crucial. This means there can be no attachments on the roof, such as a solar hot water system, PV panels, sky dish.
Windows
Windows from macrocarpa were made bigger than usual in keeping with the large scale of the rooms and the presence of the logs. 200mm was allowed for around window frames for settling, but the decision was made to make the window frames bigger as there was little settling as the wood was dry.
Finishing Touches
The floor has been finished with a low-VOC polyurethane. A restored coal range sourced from Masterton takes pride of place in the kitchen and is Jan’s favourite feature in the home. A last minute addition to the build was a cellar, which functions very well as a very cool storage space. | 
