3mo ago

Kiwi firm designs low-cost, fast-build house

www.rnz.co.nz

A New Zealand architecture company has designed a three-bedroom house that three people can assemble in six weeks for $335,000.
RTA Studio just constructed its first 'Living House' in Rotorua.
It is 85sqm and designed for quick assembly once the foundations are in place, the cost includes a functional kitchen with appliances as well as flooring, lighting, carpets and heating. It does not include the land value.

22 comments

fast, cheap, good; pick two
i wonder what the quality is
- It's really specifically tailored to reduce the labour required. I think the quality reduction is in the design, it's not exactly the prettiest, they said all plumbing and electronics are designed to be together to reduce tradesman hours (does that mean you don't get hotpoints in convenient places?), all will be exactly the same (you can already get cheaper houses by mass producing the exact same design).
  I am also not a fan of high ceilings, which can be hard to heat. Corrugated iron for all cladding is nice and cheap but not exactly the nicest looking.
  I wonder how this compares functionally to a flat pack house. It might not be that much different, in terms of both price and function.
  
  Simplifying design is exactly what should be the answer to a housing crisis IMO. Nowadays we build too many houses with upper middle-class designs (and costs) because they're the only people who can actually afford houses.
  But go back to the sorts of builds from the 70s & 80s. Typically around 100-120m2, 3 bedroom, rectangular. Yeah they're not architectural delights, but they kept families dry and warm.
  Nowadays in a lot of places we're building in-fill town houses with a similar aesthetic and I know a lot of people don't like it but I think overall its probably a good idea. Even in smaller centres like Hastings it can work so long as we get the community spaces right as well.
- Yeah, you can get a shed from bunnings and assemble it yourself for a few hundred dollars, doesn't make it a good house though.
  No mention of insulation, which should be a top priority for low income housing, otherwise the heating and cooling costs will be crazy.
  Also, doesnt fisher and paykel have a fairly poor reputation for reliability?
  
  If I'm reading it right, the walls are prefabricated pine panels 120mm thick with corrugated iron external cladding.
  No idea how that would compare to typical timber framed construction. Probably no worse.
  
  No mention of insulation, which should be a top priority for low income housing, otherwise the heating and cooling costs will be crazy.
  I eventually found this site: https://livinghouse.nz/
  It has this cost breakdown:
  There's also this more detailed breakdown: https://livinghouse.nz/#living-house-cost-breakdown
  It seems it does have insulation, as they allocate $15k for the cost of insulation including delivery.
  Heating is via a heatpump (with power partly provided from the solar). The place is only 85sqm so it should be enough to keep it cosy, since it will have to meet modern insulation requirements. It also uses a heat pump hot water system which should save on the power bills.
  Also, doesn't fisher and paykel have a fairly poor reputation for reliability?
  Yeah I generally avoid them. Lucky thing is that the site explains that they are not builders just architects, you buy the plans from them then find a builder to build it. They have agreements with certain suppliers to bring down the costs but presumably you can decide to buy different appliances.
- You can get some cost mileage out of standardization and scale. Wanting everything custom-made will drive up prices, and not building at any significant scale also does the same
I love that there's some bright sparks tackling this from a different angle!
Policy is one thing buy the more novel approaches the better. Good on them!!
Prefab housing has been a thing for a very long time all across the world. There are massive economies of scale and automation when you build panels in a factory and just assemble them on location.
I don't know why they never caught on NZ but I suspect it's a combination of regulations and lack of will from the public.
Having said that even 335,000 seems like an insane amount of money for the house alone. Given you can't buy land for under 500K in most places that still puts the total value at about a million dollars or above.
- Yeah that's what I was looking at, its nearly $4k / m2 which is kinda crazy.
  I'm trying to find papers showing cost of building over time but so far only got to this one where it was demonstrated back in 2008 (by a now merged Department of Building and Housing) that a starter house could be done for less than 1.5k/m2 - and that included labour.
  
  Yea that does seem super expensive. In all honesty though the way to go is multi story multi residence buildings AKA apartments. Best bang for the buck and better for the environment.
  
  OK, found various sites with various estimates, but all of them suggest that this pre-fab and build yourself is probably overly expensive.
  2022 - $2460 / m2 (https://www.moneyhub.co.nz/building-costs-per-square-metre.html) 2023 - $3145 / m2 (https://mortgages.co.nz/what-does-it-cost-to-build-a-house-in-nz/) 202? - $3500 / m2 (https://www.buildingguide.co.nz/planning/building-costs/)
  That last one is an estimate for the very basic level, which I think is pretty close to being better than this pre-fab option.
I think this is pretty cool. Obviously every house looks the same but they have shaved a significant amount of labour out of the process, saving a huge chunk of money.
Does anyone know how much it would normally cost to build a 3 bedroom 85 sqm house? The article doesn't mention a comparison price.
- You'd also have to add the solar system and appliances to make a comparison.
  
  Yeah, it doesn't have specs but I'd guess $15-20k of solar and appliances. It would be pretty awesome for building state houses.
Compared to a lot of builds $335k is low cost, but in terms of affordability its still stupidly expensive - and my gut feel is that the benefit of smaller, pre-fab, self-assembled, lower-quality panels here isn't turning being passed through to the final cost. Also, is a CLT just a newfangled SIP? I wonder if a better option is a pre-assembled deliver & drop house, if Brittons etc can move around 120m2 Villas surely we can design 2-4 part new houses that can be built off site, under cover and then driven and fit together on site?
My first house was a 2 bed 84m2 ex state house built in the 40s. It was fine for a couple and a dog but being a 40s design there was a lot of space utilised in a way that modern houses don't do. We had a large kitchen/dining, which was separated from the lounge - nowadays open plan gives the illusion of more space at the expense of cooking sounds & smells being enjoyed by whomever is watching TV :) But the advantage is they could fit a 3rd bedroom into a small home which makes it an option for families.
- I was thinking a bunch of these would make good state houses. Their current pricing is based on negotiated prices, but if you said you were going to build 10,000 I'm sure they could reduce the cost some more using economies of scale.
  With that said, the land is still expensive (and in many places still likely to cost as much as the house and possibly more). If we were gonna build in bulk, we would probably want to fit more houses in. Ultimately these are still standalone houses, and you could probably get a cheaper overall cost by building medium density two story terraced housing to really cut down on that land cost.

22 comments