Starter home design winner Tony Koia talks costs for mass-producing affordable homes with lower running costs; Also eyes Christchurch opportunities

Starter home design winner Tony Koia talks costs for mass-producing affordable homes with lower running costs; Also eyes Christchurch opportunities
Tony Koia's starter home design

By Alex Tarrant

The architect who designed an award winning "starter home" in a Department of Building and Housing competition reckons the 120 square metre three-bedroom house could be built en masse for less than NZ$200,000 each, excluding land costs, although he says this could still be hard to achieve.

The Labour Party referred to Tony Koia's starter home - unbeknown to Koia - in its KiwiBuild policy document, outlining Labour's plans for the government to finance then sell 100,000 homes at an average build cost of NZ$300,000 over ten years.

Koia Architects designed the home for a category of a 2009 DBH competition calling for simple, affordable home designs with a maximum floor space of 120 square metres.

Principal Tony Koia told the houses could be built in a group of about ten for around NZ$1,400 (including GST) per square metre, or about NZ$170,000. However some finishing touches would be left for the owners. The design also includes a covered porch of about 39 square metres.

Koia said the design was not as low-cost as it could be, as the firm took expected running costs, such as heating, into account, and designed it with these in mind. Spending slightly more on insulation up-front meant running costs would be more affordable over the longer-term, he said.

Koia told the house was designed to have bits added on if need be.

"You can add entrance foyers, add on garages, or add on master bedroom wings afterwards. So it’s an additive house rather than trying to provide something with a double garage that you don’t have two cars to put in. It can grow with your needs," Koia said.

While the standard house entered in the competition contained three bedrooms, since then, Koia had developed a whole series of homes, studios and garages under the name Smarthouse.

“We’ve got smaller studio homes that start off at around 60 square metres, and build up to around 200 square metres," he said.

NZ$1,400 per square metre including GST

In terms of building costs, Koia had some initial reports done that suggested ten of the houses could built together at one point in time for about NZ$1,400 per square metre, including GST.

“Now that is hard to achieve. It does take some volume and it does have some exclusions in terms of site works and finishes that the owners need to do themselves," Koia said.

“But on volume, they [DBH] were looking around that kind of figure," he said.

Koia did build two of the houses at around that cost.

“Clients were often adding things to them though, as they do, so that increased the costs.”

“We tell people for one-off houses you should probably be looking at around NZ$250,000 plus GST [excluding land]. That covers some site works and some more finishes. But they can be scaled up and down depending on what your appetite is to finish them," Koia said.

Affordable running costs

“What we’ve realised even in producing a couple of those houses is that, what’s affordable to one set of people is not affordable to another. So what we’ve actually focussed the home on is a higher value, but concentrated on the whole running cost of the house," Koia told

“A lot of group home builders are looking at the lowest cost. We think that’s the wrong way to actually look at it. You want to look at what’s the actual running cost. Because the lowest cost houses have the highest running costs, and they penalise the people who need the low running costs," he said.

“We use 150 mm studs throughout the house. They offer 50% more insulation than a standard house. For a couple of thousand dollars, we think it’s much better to have 50% more insulation than to be losing that amount of money probably every year in a cold climate.

“Yes, you could do lowest cost, but we prefer to focus on best value,” Koia said.

Koia was looking at different building techniques and insulation options to make running costs even cheaper. Recently he began to look at how to incorporate Structurally Insulated Polystyrene panels (SIPS) produced in Rangiora by Thermax.

The panels were significantly more airtight than what was currently being used, meaning running costs would decrease substantially.

“We think that will have some big advantages for mass production," Koia said.

Koia was working to produce SIPS houses for the Christchurch rebuild. It was looking at an eight unit development in Christchurch at the moment, while also entering a competition to develop ‘The Hive’, a 50-plus residential development in Christchurch which would include a range of unit sizes from studios up to four bedrooms.

“It’s still early days in the design process, but we’re trying to design a product that will achieve something for a broad cross-section of the market. We’re doing that not just to maximise sales, but in a community of 50-plus accommodation units having a cross-section of people is just a lot more healthy socially," Koia said.

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Good start, but this is architect-led and that build cost/sqm is still very high.  True mass production needs real engineers, scale, factories, attention to logistics and packing, and trained on-site installers.
Call me an old cynic but I smell talking the book here, not real scale mass-production.....

Hard to know how good it is passive-solar wise. That's a major part of the running cost, set to be majorer.
The DBH has a habit of justifying it's code, by running competitions which only come under it's umbrella - my approach wouldn't have been allowed. The shutting-out of a section of the options, always produces flawed results.

In terms of a "real engineer" well Im a BEng (Hons) in building services engineering and you are generalising and badly.  There are good architects and bad, the above one looks better than most Ive met.  My defination of bad are as per article and even your statements "$1400sq/m is still high"  All you are looking at it seems is the first cost, that is the wrong way....TCO (total cost of ownership) is the way to do it. 
We are also also talking a very standard design philosophy.  There are otherways such as earthships which are game changers.

Waymad - This is nothing but smoke screening the underlying problems.
Labours Kiwibuild policy problem are pretty obvious.

  • People with all their assets in Trusts will be able to purchase a kiwibuild home as they don't own assets in their own name.
  • People with their home asset in a Trust do not actually own a home the Trust does. These people are therefore assessed and included in the percentage of people who do not own a home.
  • The Councils exorbitant charges will not be addressed.
  • Land Zoning issues will not be addressed.
  • The associated Government costs of home ownership will not be addressed.
  • Product failure issues will not be addressed.

It would be wishful thinking to believe that any Government or its controlling Agencies would have the skill and ability to deliver affordable housing and have the necessary skill and expertise to manage any type of mass production regime. They can't get their school teachers paid on time let alone manage affordable housing. 

all we will need is a rovers return and we will have our very own coro street

I'm Ena

These are perfectly affordable according to the agents:

If you want the ultimate in affordable living, and low cost construction, the included should be the best.
Personally I think dome houses are an eco-focus overkill (domes are hard to build to feel good) but if you're into earthquake resistence it's certainly the ultimate. And expanded polystyrene has incredible insulation. this space I'm just finishing a blog post relating to this (if I may direct to my own ideas).

Um, I'd contain my enthusiasm here.
Stewart Brand, the Whole Earth Catalog originator, admitted in 'How Buildings Learn' to his ghastly mistakes in pushing Buckminster Fuller's geodesic domes, way back when.  The issues included:

  • weathertightness (particularly on the upper panels)
  • Impossibility of extension/alternative entrance/egress
  • Echo-chamber acoustics
  • Waste space given angularity of human beings, furniture, bathroom and kitchen fixtures
  • Proven by the dismal record of resale values for domish homes.

What's changed?

True with the echo-chamber effect...especially if you don't employ a ceiling. Weather tightness shouldn't be a problem with a simpler dome structure (as I linked), using good adhesives. I "retro-ed" the idea here...though hardly a dome.

I commend any action in the Affordable Housing sector.
If the DBH believe in this product why dont they invest in a practicle build of ten of them, im sure they would have the ability to over see 10 of them constructed, then come back and share the cost data.
There is a very big difference in running the numbers in theory and then applying a spend and build in the real world.
After the DBH have been gouged and delayed by local councils we would then have an accurate timeframe and costs.

yeah and if you want to see the end result of that, take a drive through Papamoa or Albany. Or just watch Edward Scissorhands. Or even see what's happening to the countryside around Melbourne and all the horrendous suburbs springing up with no public transport and no amenities.

I'd prefer to see quality apartment complexes that utilised the available space better and provided shared area's for residents to use, then extra land set aside for parks and public recreation areas. Less sprawl, less infrastructure, more efficient economies of scale.

And best of all - less annoying suburban gits using petrol-powered gardening tools on the weekend!

Devil's in the details, chaps and chapesses.

  • Modular design (particularly synchronising service entrance/egress point for power, water (potable and recycle), grey waste, black waste).    This is largely a software, not a wetware matter.
  • Exterior decoration.  The architects may come in handy here.   
  • Choice of materials - wood, wool and concrete would seem to rule here as we seem to have had them before Oil, so pass the Sustainability Smell Test.
  • Factory and production planning - because this stuff is assuredly not gonna be bashed into place on site from raw materials by inefficiently drug-tested hammer hands.  Lots of jigs, dies, CNC tools and robots would be my pick.
  • Logistics - how to drop-ship hundreds of these units to the right end site in the right sequence at the right time and with minimal attrition.  The container and courier industry have this tracking down pat.
  • Sales - online with a Web-CAD front-end hooked into the production software and a bunch of workflows to make sure that silly configuration errors cannot occur.  Been happening in the hardware side of IT for a decade or more now so plenty of precedent.  Cuts out a lot of ticket-clippers.
  • Nation-wide type approvals, so the end purchasers don't have to run the gauntlet of umpty-ump local Gumnuts desperate for fees, levies, contributions and any other revenue category that doesn't roll up to 'Rates Required'.
  • QC from factory floor to assembled product on site.  The IT industry again is the guide:  the products are perfectly commoditised, it's the configuration and set-up which needs the attention.

Needless to relate, this does not exactly resemble the 'building industry' of today (as we so quaintly term it......)
But something like what I've sketched above is what it would take to make this sort of build possible.

Waymad: correct:
That architect character in the body of the article above seems to be a bit astray in his en-masse (his word) calcs of $1400 per m2
To repeat an article from a (fair-dinkum) builder from a coupla years ago - here at in March 2011
by petrus1942  08 Mar 2011, 10:17am
Come down to the Manawatu - I will build you our 220m2 house, 4 bed, int. access garage, 2 x bathroom, brick & Longrun roof - on concrete slab for $230,000 inc. gst. Thats $1045.45m2. Comes complete with heat pump (ducted to 4 positions). Excludes floor covering, land or any site work (drive,path etc)  The building consent fees $4,300 inc. gst included. Drawing fees included.  FIXED PRICE
Now Petrus, if you are still around, if you were given a secure guaranteed contract for 2,000 houses (120 m2) per year, every year for 10 years, could you get your $1045 m2 any lower with economies of scale? You would have time to gear up.
One thing missing here at is someone contacting the kitset people Fraemohs and Lockwood and asking them the same questions. How much for 120 m2 if they had a commitment for 2,000 units per year.

Of course the fly in the ointment of Petrus' plan is that by the time you add your section plus services plus sitework plus floor coverings plus a few other odds and ends not covered in the $230k, you have shot up to over $300k (not sure of section prices in new subdivisions in Palmy but I suspect they are over $70k).

Last time I looked there were quite a few OK 4-beds for sale under $300k in Palmy and in suburbs that are reasonably close to the city centre as well.

So you'd either have to be in an area that really needed new housing (currently only Chch and Dorkland), or you'd need a subsidy from the govt.

That was for 220m2 .. one-off .. We're talking 120 m2 as per the architect above, and many of them, with economies of scale .. 2,000 units a year, limited number of plans.
On land supplied by the government.

On land supplied by the government

Sorry, didn't realise we were playing make-believe here.

That's what labour is proposing .. they commandeer the land .. sub-contract out the development of the subdivisions, sub-contract out the housing ... 10,000 houses per year for 10 years .. 5 builders .. 2000 each .. 5 plans each .. 25 plans to choose from .. what's hard about that? .. too easy

Good one, i'm still chuckling....

That sounds like a good deal but these smaller homes without built in garaging will always cost significantly more per square metre. Garaging is not much more than half the cost of the rest of the house, still all the expensive rooms - kitchen, bathroom - more external wall area to floor area, same connection charges, driveway etc. 

ONE POINT. Let's say you get the construction cost down by 50% (I like to be dramatic). Will house prices fall by that? No way. As the construction cost goes down, the land (or other) costs will approximately proportionally go UP. Cutting costs on one level will ultimately subsidise inflation on another....
Until you get rid of the undersupply the prices are bidded up to the maximum of what the market can afford. Restricive land zoning gets the last laugh.

Much as though it does not please me to say this; somebody in China will be working on a factory built housing system that meets all our regulations.  It will be able to be packed into a couple of 40' containers, look sensational and be abled to be assembled in a matter of a few weeks by a minimum number of tradesmen.  All for the cost of less than $600-$700 per square meter.   The motivation to achieve this is enormous.  Think of the impact on the world market.  We need to pull our fingers out real quick.

Loksa was set up with this concept. In liquidation before they go off the ground unfortunately.

Before we re-invent the housing wheel we already have some brilliant mobile homes that have been available in NZ for some years.
Have a look at:
Take a minute to browse before condemming them out of hand. I have stayed in one and if I had not been told would never have known it was a trailer home.
These are the sort of affordable solutions we should be targetting for initial homes.
Check out the prices for each model as shown on their web site and please look at the range before jumping to conclusions.  They are a real alternative and available right now.

Sure you can build a house cheaply. But many will only just meet the building code in terms of insulation etc, which is essentially false economy in the long run for NZ. You however want to exceed those minimum standards, such as insualtion, as it will reduce energy costs over the life of the building, and mean healthier people, which will cut on health costs. However developers will often build houses to the minimum standards to maximise their revenues.

In Auckland surely the elephant in the room is land cost. Known facts are that land outside the existing urban area is basically one tenth the cost before servicing. So telegraph to the hoarders of land that calls will be made to give priority to land owners who are prepared to make available land that can meet a prescribed cost base and that servicing will be done quickly to allow builds to start.
Also encourage satellite hubs with planned a commercial and industrial core.
Add that to the Labour proposition and it may frighten a few who now think they can afford to wait.

Cheap houses are all most folks can afford in NZ, so let them build what they want and can afford, without resorting to borrowing from usurious banks.
As for insulation, we still have an abundance of hydro electricity in this country, but this has been hijacked by privatisation and now any efficiency gains made in this area don't result in lower power prices, simply absorbed by the phalanx of paid consultants, marketers, PR reps and other hangers on, all of dubious value.
The whole electricity infrastructure was immediately devalued when New Zealand Electricity Department (NZED) devolved into the state-owned enterprise ECNZ. i.e when the smart suits took over, who know absolutely FA about running about a Hydro dam, but are experts in chardonnay lunches and trying to justify thier B.A. (Hons) in basket weaving.

Electricity in NZ is another problem altoegther. But house can largely be heated at no cost with passive solar design and insulation. Many houses in NZ still have zero insulation, and health problems, mould etc result.

Interesting run of comments.
Just remember that even as a one-off, you can build well-insulated and passive-solar and south of $400/sqm. Minimal labour too.
That would just get cheaper if scaled up.

From looking at the costs a lot seems to be in the fitout.....ppl want/expect  "luxury" so Ok live with that premium. strikes me that there is a lot of "value add" in the system that isnt really, Hugh ignores that monopolistic (and other) aspect.
I do partially agre with Hugh on the land cost, however really de-zoning wont fix the prices, not unless huge quantities are freely released with no middle men.

We dont have an abundance of un-tapped hydro in NZ....not from what I have read. Please point me at some URLs showing economic sites. Now we do have tidal in the cook straight as a huge probability, wind and even geo-thermal....but really to put in plant there needs to be a economic need.
Insulation achieves a second benefit the house is more comfortable.
Not so sure about the SOE model being poor either, it seems pretty effective.
NB Prices are rising to meet the costs of more and replacement infrastructure as much as anything else...

Steven - no, but we have a lot of efficiency potential, and a lot of current activity will go west in the coming years. If Tiwai goes, for instance, we could (back of the envelope this!) electrify our urban car fleet with the existing supply.
Not sure many folk realise that 'going to work' won't be part of the scenario, though. Maybe it could be used for something else - electrified food distribution maybe.

Labours policy of building 100,000 standalone homes (000's in Auckland I assume) would seem at odds with Auckland Councils vision of high density apartment living for Auckland?