Hi All, 


Working on making my newly purchased 1930s bungalow more energy efficient and have a few questions about insulation (Particularly underfloor insulation).


Being a old house, at some point it has been extended resulting in difference ground clearances, any way I had a consultant from Brightr come and quote. Part of the house was too low to be insulated (29cm between ground & bearer) so was quoted $1,623 for ~42sqm of Underfloor insulation (Mammoth R1.5) and a Moisture Barrier where this could be installed (this would leave ~90sqm with no underfloor insulation which are are the main living areas & 2 of the bedrooms).


In addition, I've recently identified that parts of the house don't have wall insulation, and the ceiling insulation is a bit "Iffy" in parts (Some Gaps and I've just replaced Halogen down lights with Leds)


So i'm after a few bits of advice: 


  • Is the quoted $1,623 reasonable for ~42sqm of R1.5 insulation and a moisture barrier
  • Are there any solutions out there for low clearance underfloor insulation (Google hasn't been helping)
  • Would you priorities additional ceiling and then retrofit wall insulation before underfloor?  

Note: I also asked about ducted Heat pump (House came with 2 un-flued plumbed Gas heaters which have been placed with electric) but was advised that supply is an issue and they are not doing Ducted heat-pumps at the moment. 


Appreciate any help and advice.





sorry to jump straight in here.




i've did this myself a few year ago.


only way to do the low areas is to dig your way under. don't dig to close to the poles, many old ones are not posts but rather just blocks sitting on the dirt.


if you cover 90% of the dirt in moisture barrier you will get 90% drop in moisture. so do as much as you can and don't sweat it if you cannot do it perfectly.


that will make a HUGE difference to your house. but be aware your floor will shrink a bit and gaps may open up.




insulation there is a few different ways of doing it but mammoth (or any polyester) is a good choice. i recommend as thick as you can, this is to cover the sides of the joists which are like heat sink fins. i've got r2.6 in some of mine. underfloor makes a big difference to the feel even tho technically doesn't make the house a whole lot warmer. thats because walking on cold floors sucks. so try to do areas that are not carpeted. 


a big thing is to seal up any gaps especially in the ceiling. a lot of the old houses where really air tight ceilings due to the plaster work, until people put downlights in them. your floor is going to be really air leaky unless you seal that up at some stage. seal up around plumbing and electrical.




heat pumps and ventilation is a another topic.