Giveaways
LAST December, I published a post about how I had put down a deposit on a HouseMe tiny house with a footprint of 42.5 square metres, after giving up on trying to build a small house of 70 square metres (753 square feet) on the same site.
I had already had a concrete block retaining wall built in 2018, with a car park below, with the intention that the small house (now tiny) would be perched on top.
Among other things, I thought that — once built — the new house would command quite good views of Lake Wakatipu and the Eyre Mountains on the other, less populated side of the lake.
For the next few years from 2018, as you can tell from the growth of weeds, nothing happened, for reasons I go into in December’s post.
Finally, in December 2023, I put a deposit on a 12.5 metre by 3.6 metre (roof size) tiny house, from a firm called HouseMe, for NZ $138,000 plus delivery.
HouseMe’s tiny houses are built from scratch in a factory, in ways that allow mass-production economies to be achieved. I note that, less than a year later, the model of house I ordered in December has since come down in price to NZ $125,000 plus delivery. I don’t begrudge this: it is good news for anyone who comes after.
The long, thin shape of the HouseMe tiny house suited my steep section much better than anything wider. It would still have been nice to go for a two-storey small house of 70 square metres on the same site, and would certainly have made the associated earthworks and retaining wall costs more worthwhile.
But what finally clinched the deal for me was that the HouseMe tiny house came with a Code Compliance Certificate (CCC), which means it is up to New Zealand’s building codes for fixed dwellings.
The other interesting thing about the HouseMe house is that it is made entirely from steel sandwich panels with insulation between, after the fashion of a giant domestic appliance like a refrigerator, or a shipping container.
Although most houses in New Zealand are made of wood, this is perhaps in part because, for most of our history, we have only had a limited ability to produce or even recycle steel in this country.
Until the 1980s, New Zealand’s ‘dead cars’ mostly ended up landfills even though each one contained about a tonne of valuable top-quality steel that could easily have been recycled, if only the facilities existed to melt it down.
But that was then and this is now. With an ever-increasing number of recycling mills and a growing number of cars in need of recycling, we now have an abundance of steel.
This allows firms like HouseMe to make modular steel houses using the same mass-production techniques as those by which domestic appliances are made.
As we know, domestic appliances have constantly been getting cheaper over the years, after we allow for inflation. And this also seems to be true of the tiny house model that I purchased.
Such modular steel houses are also likely to be lighter and stronger than anything made out of wood, which would in turn make them more portable and easier to lift. After all, that’s why cars are made out of steel rather than wood.
I suspect that now that we have abundant steel in New Zealand, this is the new way to go.
Getting back to my site, the next step after putting the deposit on the HouseMe tiny house was to widen the flat space above the concrete retaining wall and get another retaining wall and foundations built. I checked out ten builders for this and finally chose one in the middle of the price range.
This was based on their experience of building on a couple of other sloping sites in Queenstown and a good reference I got from the owner of one of the houses they had built on those sites.
And so, I signed a contract which provided for the builder’s work plus earthworks to be done by a subcontractor the builder had chosen. The contract said that the subcontractor would remove 40 tonnes of earth. The contract was checked out and amended by my architect in Auckland, and all seemed straightforward.
On the 17th of June 2024, after a few delays caused by the earthworks taking longer than expected, my house was delivered: what a great day! Here’s a film that shows the HouseMe house being craned right over the top of my existing house further up the slope, and lowered onto its site.
In the video thumbnail just above, you can see that the house sits on grey steel I-beams that poke well out over the top of the block retaining wall and rest on the retaining wall, and on piles some way further back as well.
The finished house slightly overhangs the retaining wall, with a deck in front that is supported by the projecting steel I-beams.
Here’s how the house came to look after the deck was finished. In this view, you can see the older house it was lifted over, at the top left — amazing!
And this was where things began to get awkward. The builder was now billing me for subcontractor earthworks amounting to the removal of 200 tonnes of soil.
This cost tens of thousands of dollars more than what was in the contract, even though the contract hadn’t been formally varied.
There were some small adjustments to the new retaining wall that had been required, due to things we had found out on site. These were agreed to by way of new engineering plans. The new retaining wall had to be made half a metre higher at the high end and a metre higher at the low end.
Even so, these changes were fairly small. It seemed that the subcontractor had badly underestimated the extent of the earthworks required, even on the original design.
We checked out the subcontractor’s website and found that the only sites that showed any earthworks were all flat sites!
The subcontractor also had a lot of trouble drilling the holes required for the massive poles that supported the retaining wall, with the result that just drilling the holes took eleven working days, spread over several weeks, with another subcontractor brought in to help finish. That was why the delivery of my house had to be put back from the initially expected date, in May.
There seemed to be a real contrast between the professionalism of the HouseMe construction, and the way that so many things seemed to be going wrong on my site, as if everyone was learning by doing.
Things that went wrong included:
A council inspector said that building things in New Zealand was always a martyrdom and that hassles were to be expected.
Having said that, nearly all of my issues were associated with the earthworks.
Although the design of the retaining wall had to be slightly revised because of lack of precision in the initial site survey, both in regard to the stiffness of the soil and the exact contour heights the actual building of the retaining wall and foundations nonetheless went swimmingly in comparison to all the hassles I had with the earthworks.
And of course, the prebuilt house just went down in an hour or so and was bolted into place thereafter. I had no significant problems getting an additional CCC for the foundations, deck, stairs, and services.
Here are a couple of collages I’ve made that show what it is like inside. The topmost collage also shows the house from outside, again, plus a view of the carpark and the deck overhang.
On reflection, it was with the earth and the soil and site surveys that all my problems and uncertainties arose. The actual business of making the house, building the retaining wall, and getting it installed all went pretty much according to plan by comparison.
(At the Queenstown site where the owner had given my builder a good testimonial, were the earthworks done by someone else? I wonder.)
I am now embroiled in a dispute to try and get out of paying some of the extra earthworks costs for which I got all these extra charges. I mean, you can’t just underestimate things by a factor of five and then expect the client to pay up.
Indeed, the law is quite strict about this: New Zealand’s Building (Residential Consumer Rights and Remedies) Regulations 2014 make it quite clear that any unexpected overruns have to be costed up and presented to the client for signoff before the extra work is done.
The moral of the story is to get earthworks checked out thoroughly, surveyed for quantities, eliminate as many uncertainties in the initial site survey as possible, and be totally rigorous about any variations required. Oh yes, and make sure that even the subcontractors, not just the prime contractor, have relevant experience.
But apart from all that, the wider paradox is that I have a feather-light tiny house, craned over the top of the old house, which sits on a platform created by massive earthworks, including the removal of as much as 200 tonnes of dirt, with mighty retaining wall posts behind.
If I had known from the outset that the house I would install was going to be so light — and that everything to do with the earthworks was going to be such a hassle — I would have arranged for a guarantee that the initial block retaining wall could take the full weight of the house, with I-beams to support the house built in at the top, and had everything designed in such a way that the house projected more and not gone so far into the bank.
It is a pity that I had to settle for a single-storey tiny house to get something that could feasibly be installed on my site, when I had permission to go to 70 square meters.
Thinking about that, there may well be a market niche for a preapproved, factory-built, two-storey house of roughly the same width as my tiny house — 3.5 m wide, or so — which could be fitted onto a sloping section.
As I say, something like this, sketched up by my friend Chris Harris for last year’s post:
Among other things, this design could be done in such a way that the first storey is put down by crane, and then the second storey is put down separately and bolted on — with insulation and even an air gap between, for soundproofing — and the exterior stairs then bolted on as the third step.
Such a design would yield high building performance. Yet at the same time it is ‘designed for manufacture’, capable of being turned out as if we were shelling peas and cheaper and cheaper all the time, just like refrigerators and other domestic appliances made in the same fashion.
Moreover, it might be possible to put in this two-storey modular house in a way that would keep those pesky earthworks, and the need for exact site surveys, to a minimum as well!
I had a block wall built to create a car park at the foot of a slope leading down onto a shared right of way. But that sort of engineering might not be needed everywhere.
What if the two-storey design for a sloping section could dispense almost entirely with earthworks hassles, by using a steel frame that included the sorts of I-beams my house went down onto, but with the I-beams resting on top of steel columns driven into the ground as per the following sketch:
In place of the columns, ground screws like those offered by the firm StopDigging might also be used.
There must be many such options for keeping earthworks to a minimum.
For, after all, we are not talking about really heavy-duty engineering, or any need for extremely heavy-duty foundations, here.
If we were, HouseMe would not have been able to crane my house over the top of my existing house as if it had been an egg carton.
Food for thought?
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