Hold on a second – NewsFlash coming through.

“Government declares that 120mm thickness is the minimum thickness of insulation required in all rental properties.”

Now – I’m a supporter of better rental standards, and better health outcomes for renters, and better Building Code requirements, but this is a bit of a tricky one. Our Building Code allows walls 90mm thick, and mandates (I think) R = 2.9 insulation in walls. So, 90% of houses are built with 90mm timber framing and an integrated insulation that just happens to fit between inside and outside faces of a 90mm wall.
So how are they going to get 120mm in there? And why is insulation being specified by thickness, instead of by R value?

If the walls have been built with 140mm timber (as I do on all my houses) then it is not a problem. Or, if walls are externally insulated with stick-on polystyrene insulation to the outside face (as per standard leaky building system), then I guess the insulation COULD be upgraded from the current 40mm thick, to one that is 3 times as thick…. but that would entail ripping off all the cladding and replacing it.

But on further investigation, the news report says this applies to Ceiling and Underfloor only.
“Under the new rules, rental properties will be required to have ceiling and underfloor insulation that meets the Building Code standard or has a minimum thickness of 120 millimetres.”

So – while the situation is a lot better, all it is saying is that the ceiling and underfloor must meet the Building Code – which surely any building must have to do in NZ? Actually – there are further qualifications to that: “All rentals will have to meet the standard by 1 July 2024, or face penalties.” So – at least 5 years away. And possibly under the jurisdiction of another Government, but not this current one? The requirement for underfloor insulation is an interesting one as well – effectively saying that every concrete slab house must (in future) have a polystyrene underfloor insulator – and that all those current slab-on-grade houses, come 2014, will NOT be allowed to be rented out.
I just can’t help feeling that this is being gone around the wrong way. Revise the Building Code first and include in it a provision that ALL rental housing must reach those revised standards. Because one thing is for certain – to reach those existing standards is barely scratching the surface. Our existing Building Code standards are lax – very low – ridiculously low. What we should do, Phil, is revise the insulation standards for walls to minimum R=4 and for Ceilings R=6. And require every new rental house, and every new home owner house, to comply with those new standards. And THAT, my friends, is why you all / welcome all need to be thinking about minimum 140 thick external walls in all new houses, as that is surely the next step that is going to come…
Cue the massed ranks of screaming “hard-done-by” property investors vowing to never vote Labour or the Greens back in again, and if they are clever, they will sell off all their existing stock with inadequate insulation, or inability to upgrade, to unsuspecting First Home buyers, who will then be stuck with a lemon in 5 years time….