Kambah Passive House

09/12/2023

Note to self. May need to check the PHPP shading calculations....

15/06/2023

Hi all. Having an open day on Sunday 25th June in just over a week as part of the International Passive House Open Days. There are two site tours available, 11-12pm and 12:30-1:30pm. Book here . Places are limited. This will be the last site visit before all the detailing gets Gyprocked in. As far as how the build is progressing, the roof is on….hooray!. The exterior cladding is almost finished, a mix of fibre cement (3 kinds of Cemintel), timber, and Colorbond. I’ll put a few pics up later if the sun comes out. The scaffolding makes it hard to see anything. Also, the last blower door test gave a result of 2.2ach@50Pa static pressurisation, and there is still over 30m2 of sub-floor (bearer and joist construction) membrane to install, so super pleased with the result so far. I can feel the air flowing through the unwrapped areas during the blower door test. On top of that, nigh on all the roof battens and wall battens have been installed, so only a handful of building wrap penetrations left to carry out. That’s heaps of holes in the building wrap with no measurable loss in air tightness. Given this is a single wrap retrofit project I’m happy with the result.
As far as living in the house during construction. Well, from day one the internal comfort levels have been rising, disregarding the construction mess, and this winter is the first winter that we’ve had a reasonable level of comfort in the home ever. The extension has been Gyprocked for several months, and we have been relying on the building wrap for weathertightness until Colorbond the roof went on. The extension gets cold, like 10 degrees C cold overnight, not being fully insulated, some areas just building wrap and where there is insulation there’s only half the insulation required. I can’t add any more until the pre-sheet inspection has been carried out. Also, there is minimal separation between the old house and the new so there’s heaps of heat loss into the extension from the old house. On top of this the external doors are normally open during working hours and the scaffold does a fantastic job of blocking the suns rays.
Hopefully this will change within the next few months….

06/03/2023

Hi, I'm having an open day for my Passive House retrofit this coming Sunday, the 12th of March at 2pm. The project is located in suburb of Kambah in the ACT. Click the following link for booking. https://events.humanitix.com/site-visit-to-kevin-s-house-in-kambah The project includes an extension and bringing the existing residence up to PH standard. The project uses only an outer wrap with the idea being to carry out the insulation upgrades (other than the addition of new windows) entirely on the outside of the building without affecting the occupants internally. A secondary roof has been added on top of the existing roof with pumped in insulation to create a warm roof and allow for HRV installation inside the thermal envelope. Bolt-on eaves have been used to simplify the external wrap installation. The house is very much a building site. So come along and see the detailing of the wraps and insulation before they get covered up.

23/06/2022

Kambah Passive House will be open 25th and 26th June from 10 to 3 as part of the International Passive House Association open days. Please message us for the address if you are interested in coming to see a retrofit passive house in progress

iPHA: The international network for Passive House knowledge; promoting the Passive House Standard worldwide

25/11/2021

Finally managed to get two of the three slabs poured. The third and biggest slab to the rear is basically a basket case, waiting for the endless rain to stop. Each time it dries out a deluge follows. This arvo we had 45mm of rain and the site took a big hit. Water flowing into the storage area under the house and soil collapse exposing the footings. I had to knock up some quick shoring when I got home from work in case it rains heavy overnight. Hopefully the worst of it is over. The weather folk say this November will be the wettest on record.
Neither slab required any Passive House modifications as both are outside the thermal envelope.

04/11/2021

After rain delays during the site cut, more rain has arrived and therefore more delays. I was hoping to get a concreting team to carry out the formwork and pour the slabs, but between Covid, rain, a tight labour market, Christmas and my lack of organisation I ended up doing the formwork and steel myself. Still need to find some conreters. Once the concrete is in the rest will be easy....hopefully!

22/10/2021

Good news. Our triple glazed windows from Logikhaus windows https://logikhaus.com.au/ are packed and on the ship from Poland.
Opted for a solid Larch finish on the inside with an aluminium clad on the outside. External colour is roughly Colorbond Wallaby. We took all the Colorbond colours into the garden and wallaby jumped out at us. It just seemed to blend in with the surroundings.
Absolutely love the look of the windows. I've fitted quite a few windows from Logikhaus previously. They look awesome from the inside. Maybe I'm biased because I'm a chippy by trade. I think it brings a little bit of nature into the house.
With regards to the price. Prices from Logikhaus were less than 10% more than for double glazed uPVC in Canberra. The 10% was for a triple glazed finger jointed pine windows, not the Larch like I have. I priced several windows types including double glazed thermally broken aluminium and uPVC. Both lots came in around $940m2. Definitely some price gouging going on in Canberra. I did find some uPVC double glazed windows around the $700m2 mark. Either way the look, build quality and thermal performance of the other windows were far below that of the Logikhaus windows. I also know from previous experience the Logikhaus windows will be airtight.
I'm not sure of the shipping time. I think it's around 5 to 6 months from order (including manufacturing). That said I have a 10 week lead time on the single glazed aluminium windows made here in Canberra.

20/10/2021

The site cut is now complete and the front and rear yards are nothing but dirt or sludge if it rains. The only issue so far if finding the existing storm water trench running directly under the new footings. The old pipe is blocked and broken so it was always going to be deleted. I've contacted the engineer for advice.

18/10/2021

With lock down ended and trades allowed on the site for the first time the site cut is underway. It's a crazy transition each day and somewhat overwhelming too looking at the bare earth where there was once greenery. Whilst the house looks terrible from the outside, the inside is unchanged and still very livable. The only issue is trying to stop dirt coming into the house. When it rains the cats leave dirty paw prints everywhere inside.

07/10/2021

This is the second part of my installing the insulation between the bearers and joists and fitting a weather tight wrap.
It took me three of four tries before I was happy with the outcome and the method. Gravity on the insulation is the biggest issue, pulling the insulation away from the underside of the floor boards.
I ended up installing strapping at 300mm centres to reduce this. I also used a 70mm underfloor batten to house a 90mm batt. I tried using a 90mm batten to house a 90mm batt but the sag didn't leave the best job. In other words I don't believe the thermal values achieved on paper would flow through to real world performance when a 90mm batt was used in a 90mm batten.

17/09/2021

This is the first part of how I'm installing the underfloor wraps and insulation.
It took me three attempts using different methods before I was happy with the finished result.
I carried out thermal bridge analysis on all the methods to check for any risk of moisture (fRsi value). All methods were fine. I also altered my PHPP file to check for Passive House heat balance verification.
Method 1 was just using strapping and a taught building wrap trying to hold up 90mm of insulation between the joists and 90mm insulation between the bearers. It was useless, with gaps between the joist batts and the bearer batts and with a large sag due to the weight of the insulation.
Method 2 was as shown in this video. Using 90mm insulation between the joists and 45mm insulation between 45mm battens. It was OK but I wasn't happy splitting the batts in half as the thickness of the batts after splitting wasn't equal throughout, some were 45mm and others 30mm. It was impossible to split them equally, and I decided to scrap that option and move on to method 3, as shown on the beginning of this clip.
More on this method soon.

09/09/2021

In this video I decided to examine the underfloor insulation to see why it doesn't perform as it should. Whilst the install job is far from perfect, it seems not far off the industry average. I often see insulation jobs in walls barely better than this where access is unobstructed.
Achieving long term underfloor insulation using Rockwool batts is difficult without spending money and effort in preventing them from pulling away from the underside of the floor boards. Gravity definitely isn't your friend. With a timber floor construction such as mine as soon as the batts drop just a millimeter or so the insulation value is massacred.