Browse Forums Building A New House Re: Canberra custom KDR 115Jun 18, 2018 10:47 pm Okay, its now (almost) a month after move-in. It's been hard to find the time to post with everything going on! Overall, we're quite pleased with how well the house is performing. It's not a Passivhaus and hasn't been done to that high a level of airtightness - but we suspect that we've achieved an even higher level of airtightness that we were aiming for, based on how poorly the dishwasher dries the dishes when the house is fully closed up. Being a fairly airtight house, and not having a dedicated ERV system, we control ventilation manually by opening windows in various combinations/locations depending on our use patterns and which areas we want to get ventilation through. While it might seem strange to spend effort on airtightness and then opening windows, the aim is to have CONTROLLED airflow, not air leakage randomly occurring in various ways that you can't turn off or redirect. The power of thermal mass and passive solar orientation also works well with this - doing several complete turnovers of the internal air volume, even when the outside temperatures are single-digit, only very slightly reduces the total thermal storage of the house, and the internal air temperature quickly returns to original levels when the windows are closed again. The reverse-cycle aircon also helps air quality through reducing humidity and helping to get rid of any excess moisture. Our strategy was always to not fit dedicated ERV, especially since we knew we were going to need some form of active heating/cooling, so we went with reverse-cycle aircon (to control both temperature and humidity) and the plan to manually ventilate via windows as needed, keeping open the option to later install decentralised ERV (like the Lunos systems) if we felt it was needed. We're definitely still considering adding the decentralised ERV, but we'll wait until we've had more experience before committing. However, we've since found out about a centralised ducted ERV system that's now available that includes a heat-pump for active temperature control - if that was available at the time, then we probably would've gone with that instead of the aircon. Our standard weekday routine has been to leave several windows tilted (tilt-and-turn windows) when we leave the house in the morning, which is enough to fully air the house out during the day, while the passive solar heating warms up the slab. Coming home in the evening we fully close all but two of the windows and turn the ground-floor airconditioner on to heat to 18 degrees (the minimum) - it runs for maybe 30-60 minutes (depending on how overcast the day has been), then only runs intermittently throughout the evening to keep the temperature topped up. When we go to bed we close all the windows (the internal volume of the house providing plenty of air for the night) and turn off the aircon. In the morning when we get up the house is still at a comfortable temperature (for reference, outside temperature minimums are currently around freezing and maximums in the low teens). Even with a couple of windows tilted for ventilation, the lack of imperceptible draughts due to the airtightness makes a surprising difference to comfort. Having the aircon set at 18 gives an internal environment that's comfortable in t-shirts. In our last house (built 2006, 4.5 star EER) we'd have the aircon set at 21, and we'd still need to wear long sleeves (if not a jacket). I wouldn't believe it if I hadn't experienced it myself, but it really is a huge difference, and just drives home how leaky typical Australian houses actually are, and how much of a tangible benefit is provided by paying attention to airtightness. We've experimented with leaving the upstairs aircon on - but if we do this the house gets too warm to comfortably sleep in (in a Canberra winter!), so we always have it turned off overnight and only occasionally run it for a couple of hours in the evenings (if at all). On the recent weekend with overcast days and single-digit maximums, we kept the ground-floor aircon on overnight set at 18 degrees - by early lunchtime the passive solar gain had been enough to heat the main living area to over 23 degrees. All this is also with mostly bare windows. The only window coverings we currently have in place are temporary $10 Ikea stick-on pleated blinds ('Schottis') to the bedroom windows while we're getting quotes for permanent curtain and blind installation - the large living area windows are currently completely bare (the privacy afforded by the battleaxe block means that we can get away with this). Obviously, the performance of the house will be better once we have proper window coverings in place. Iincidentally, I can definitely recommend those Ikea blinds as a temporary option as an alternative to the traditional 'old bedsheet' treatment - they don't require mechanical fastening, so no need for nails or screws, and for what they cost they're quite serviceable. The internal soundproofing is working well. Upstairs footfall is still audible below, but only as muffled bass sounds - noticeable, but not intrusive (and ambient noise doesn't seem to carry between floors at all). It's no longer an option to yell out to someone on the other floor, or even at the other end of the same floor if the doors are closed (which admittedly sometimes does have its downsides, especially when kids are involved!). We had a couple of minor maintenance issues - the tempering valve on the hot water needed replacing due to a weird flow-rate issue that would sometimes see us without hot water unless we ran two taps at once, a toilet roll holder needed replacing because it was slightly out of alignment and wouldn't close properly, the concreter took three weeks to drop off a metal cover for the drainage access hole in the driveway, but nothing of huge significance. There were some delays with the final painting defect fixing, which also held up the installation of the wooden steps for the doors - but it's finally all been done (although we're still cleaning up random bits of paint splatter - they weren't the cleanest painters ever). The most painful to fix issue is a cosmetic one with some of the tiles in the main living area - they've been bleached in some places by an unknown chemical, and will have to be smashed and replaced (fortunately we've got plenty of spares). The tiler should be coming back in the next few weeks to do this. I'm still struggling to take photos that show proper colours, but here's a quick shot of the Karndean to give an idea (the colours are definitely richer in real life, though - the lighter tones are particularly washed-out in this photo): Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Re: Canberra custom KDR 116Jun 19, 2018 10:03 am Fantastic write-up, as usual Algernon! Great to hear all the energy saving measures are paying off. The upstairs floor looks great! I can't differentiate if that is real timber or not from your picture, very impressive. Cheers ligongl Re: Canberra custom KDR 117Jun 20, 2018 9:22 pm Algernon, Great news that your home is working so well for you - it's terrific when all the planning pays off! Long may your comfort continue! Variegated Re: Canberra custom KDR 118Aug 23, 2018 9:53 am wow, your posts are incredibly informative and useful! Your attention to detail and research behind every aspect of your build is impressive, I only wish we stumbled on your thread a year earlier! We are five months into a custom build and whilst we thought we were organised and we’ll researched we have nothing compared to you. Unfortunately we had no experience in the building game and planned and researched for about two years before signing a contract. However you don’t know what you don’t know and so whilst most things are coming together there are some frustrations, and some areas we feel the builders are taking us for a bit of a ride. I was particularly interested in your energy efficient features, Canberra gets so cold and we were keen to avoid the freeze as much as we could! In the house we knocked down olive oil would freeze in the kitchen!! Wish I picked your brain earlier! Congratulations on the final product! Re: Canberra custom KDR 119Sep 03, 2018 11:55 am Thanks! We did put a lot of effort into planning and research - but yes, there's always the "unknown unknowns", and we've had a few of those. Now that we've built one house we'll be much better prepared for the next! (Just kidding, not going to be going anywhere for a while). There really is a lot of stuff that comes up - the trouble is a lot of it is second-nature to those who do it all the time, so even if you ask them they won't necessarily think of it as something to mention. Accepting early on that it'll never be perfect certainly helps a lot, and ironically means that you'll probably end up closer to perfect than otherwise (stressed and worried people don't tend to make the best decisions, especially under time pressure). "Good enough" is definitely good enough - our house, for example, isn't a Passivhaus, doesn't incorporate a range of new systems and technologies, doesn't use SIPS or ICF or any other 'non-standard' construction style that might have been 'better' - but it's still significantly better than most houses out there, and is close enough to 'perfect' that doing anything 'better' will involve a lot of extra cost for only a little marginal more benefit. Eight stars means very comfortable living with minimal utility expenses (and is good enough for potential future energy independence via PV solar and battery storage). Re: Canberra custom KDR 120Sep 03, 2018 11:55 am A quick update on how the winter's gone: we're definitely not getting our money's worth out of the upstairs aircon! (although it'll be used a lot more in summer). We've got our fist permanent window coverings in - roman blinds on the downstairs living room windows. The reverse-cycle heating has never been changed from the minimum settings, even on the coldest nights, and the upstairs aircon has only been run a handful of times for (at most) a couple of hours in the evenings (generally on the coldest days where it's been overcast, reducing the passive solar gain) - even then it's just been to take the edge off the slight chill, rather than *having* to run it just to be bearable.
We've had some hot water issues and had to have the tempering valve replaced (under warranty) - hopefully all solved now, although I'm starting to suspect that there might be a crossover issue with the laundry mixer tap - we'll keep an eye on things and see what happens. Our new steam combi oven unfortunately had an issue (the steam part didn't work properly) and had to be taken away to be repaired - it couldn't be repaired and had to be replaced, but we're waiting on the replacement to arrive from overseas. All covered by warranty, and a big shoutout to the customer service from Winning Appliances (including chasing up the manufacturer and the repairer on our behalf when needed) - but we've had an oven-shaped hole in our kitchen for several weeks now (our microwave is an oven-micro combi so we do still have a functional, if smaller, oven to carry us through). We've also started the final landscaping planning, and planted our first tree a few weeks ago (a red oak sapling, which as it grows will become the centrepiece of the northern yard). It's been a dry winter, so it hasn't usually been an issue, but when it rains the bare front yard quickly becomes very muddy (clay mud too, the worst kind). Wow I hadn't realised things had gotten that pricey in just a couple of years since I built, that is crazy with how much land is now costing if you aren't lucky enough to… 3 7541 Hi Im having trouble getting anyone to provide useful advice on going for an insulated slab North facing extension. I had Lighthouse group do the energy assessment last… 0 2306 We were lucky in that our old house was so small (86 square metres) compared to the new house, they were able to take enough readings around the old backyard house before… 8 38507 |