Architecture is probably biggest help, as we just bought an Existing Designer home that is about 16 years old and we have no need for an Air Con through summer, most we use is a Fan or two just to Circulate the Air.as the way the designed the house was to maximize Natural Light so we dont use house lights during the day which saves a fortune on electricity bills but then also in winter for natural heating (although we do have under floor heating) but then also the way the house was designed was to make use of the cross breeze for cooling in summer as well as they lowered the block of land to build the house on as Hot Air Rises, they also built the house with Double Cinder Block Walls for insulation. In the near future we will be wanting to buy Solar Panels and Battery Packs but just waiting for the Batteries to become more cost friendly. We run on full electricity so we dont have a Gas Line. Only Electricity and Water. One day after Solar Panels we will want to add Double Glazed Windows then our bills will be close to $0 apart from Land Taxes

My parents have used a wet back combustion stove in their early 70's brick veneer dwelling since they built it. The wet back is used for cooking, heating and heating the hot water system which has a hot water cylinder then a header tank in the roof space. It has 4 hydronic radiators to spread a bit more heat to the separate meals room and to a sitting/breakfast area in the kitchen. A combustion wood heater is in lounge room. The dirt and dust seemed to come from bringing the wood inside rather than from the heater itself apart from the cleaning of ash from the fire box.

It all works very well and after almost 40 years they have just replaced the Hot Water Cylinder. The stove fire box needs regular cleaning but no more than a wood heater. The key is a good supply of dry wood which being on a farm isn't an issue.

Dad (80) spends a couple days each year sorting the wood situation.

My advice would be to design with the intention of no heating and cooling aid's, but allowing them to be added in to improve the comfort level's, as you noted. Hydronic heating while sounding good can be expensive to install. The pipework in the slab is not too bad but the rest of the system is expensive. Manifolding, etc.. Spending money and using resource's to have it doesn't seem environmentally friendly to me. Minimise the extra expenditure that only does one thing, heating the floor....unless it's the only option available.

What do you need LPG for? Cooking?

Probably better to use Solar panels for electricity (with a battery wall later perhaps when they're cheaper and even more efficient) for lighting and power point's, with wood for cooking, hot water and heat. A well designed dwelling should be able to achieve this without needing floor heating.

Can bedrooms be North facing as well, this could mitigate the need for heating these rooms almost altogether. Will your site allow the passive orientation to actually work and be private as well? Neighbour's and tree's don't help here..... A design should site specific rather than based on theories. The site will tell you what to do! Hydronic heating may be a requirement to make some rooms comfortable depending on the site but I'd have it as a last resort only.

Look at using reverse brick veneer as internal walls can collect heat from sun as well as a slab. Have everything do more than one job, roof for protection as well as collecting rain water and supporting solar, etc..

Giuliano is correct about slab insulation, well worth the spend!

Thanks JPM Creations. Yes we plan to ensure our design will
mean we do not need air con and will only require minimal use of heating. In
the area we live, we know of a few homes that have been built recently, which
were designed to not need heating/cooling by using passive solar design
principles, however heating has still been required or had to be installed
afterwards. Where are you located and can you tell me how often you need to use
your in-floor heating?

Thanks for all your advice Giuliano.

- Any wood fired heating
we have would be purely run with wood from our farm, as opposed to buying
anthracite. We would really like to have woodfire doing at least two jobs, i.e.
cooking and heating/heating and hot water/cooking and hot water (as we are
under the impression that solar hot water would not be enough in winter??).

- We
are planning to insulate the slab, but have not gotten as far as deciding what
product we would use, are there several different products like the one you described?
We do plan to have polished concrete flooring throughout the entire house –
with the possible exception of bedrooms on the south, if absolutely necessary
they will have carpet.

- We will also be aiming to have the optimal amount of glazing for solar gain (and prevention of heat loss). I still haven’t worked out why I can’t upload a picture
of our plans, but will do ASAP as we would love to hear feedback on our plan.

Thanks MB Design and Drafting.

- Yes, hoping we won’t need
heating/cooling aids, but as I mentioned above, other new, passive-designed
houses in our area have required heating (although, they don’t have full slab
insulation, as suggested by Guiliano above). How do others, in our climate, successfully cook, heat and have hot water in an off grid home?

- Yes, the cost of hydronic slab
heating system is something that has driven us to look for other options. We
were aiming to have a woodfired stove multitasking as our source of hot water
(secondary to solar hot water), cooking and floor heating – but $30K
uninstalled is a bit much. Is there are more effective way to heat a house with
a woodfired oven? Are radiators the only option? (I’m not super keen on their appearance or having
to dust them).

- We plan to have a 5kW solar system and will only have
bottled gas for some cooking, so that we can boil the kettle/cook in summer
without having to light a fire. Now we are wondering if a larger solar system would meet some more of our needs? At the risk of revealing how little I really know about all of this(!), I have to ask, are there electric cooking options that can be run by solar power? How large would a solar system need to be for this?

- At this stage, we have kitchen/dining/living, master bedroom
and ensuite, and 'outdoor room' all facing north. We have 70 acres, so there are
no concerns about neighbours or trees impeding on a passive orientation. Is
there a way to design a floor plan/roofline which would provide passive solar
heating of rooms on the south?

I hope I make sense. Please feel free to chime in on questions that I have posed to others. Thank you all for your time in helping
guide us through what seems like an overwhelming amount of information to get
our heads around.

We are in Warragul Victoria .. we use the heating obviously only during winter, but benifit of our heating is that it is zoned so we can heat only the rooms we are using at any given time so its not wasting power heating the whole house, plus due to the way they built the house with Concrete blocks double thickness is that it retains the heat so even when we turn floor heating off the inside layer of blocks have stored some of the heat so acts like one of those Oil Heaters.. in our old place we had gas ducted heating but was still relatively expensive as the whole house would get fully heated even though in reality we only used 3 maybe 4 rooms out of 7+ plus then we still had electricity bills for rest of appliances . this way we we save money as we are only on electricity and we dont have to pay for the Gas Services and Tax each year. And at the old house we had 18 or 20 4kw panels i think if i remember properly and we had a surplus in our electricity account where they owed us up to $700 at one point over the summer period due to our luck of having the roof in a way that panels where always getting hit by the sun. Only reason we have not gotten solar on new place yet is because in Warragul they only allow 18 panels at 3.5-3.6kw and still battery packs are expensive to get the amount we would like

- Any wood fired heating we have would be purely run with wood from our farm, as opposed to buying anthracite. We would really like to have woodfire doing at least two jobs, i.e. cooking and heating/heating and hot water/cooking and hot water (as we are under the impression that solar hot water would not be enough in winter??).

There's nothing like lighting a woodfire to keep your house warm, except for the great big hole in the insulation that it causes. As beautiful as they are (and I'm a massive fan of open/wood fires), they are pretty bad when it comes to ceiling penetrations. A lot of insulation is lost by having an open fire, a wood heater not so much, but still bad enough. For heating, the best advice I can give is this. You need a battery storage system! Then whatever type of heating you go for, you won't run out of energy for your cooking, cooling or anything else you won't to run at the same time. I believe this is a necessity, not to mention a very smart investment. If you want to be off grid, then be completely off grid. I personally don't believe in still being connected to the grid and having the energy your home creates, sold back to you for an absolute pittance. If you invest in a good battery set up, it'll last you up to 15 years and you'll have never have to worry about heating or cooling. I visited a house about 12 months ago that was off grid for power. They purchased an induction cooktop and electric oven, that way the idn't have to worry about refilling gas bottles or having a gas bill come in either. They didn't have the smartest idea when it came to lights as they were still using halogen's, but even still, their battery system never went under 80%. Even during winter, with two teenagers, and a couple of plasma tv's, playstations and all other sorts of electrical goods that they used. They were never too careful so as to make sure they had power in reserve. They just lived life and if they needed to make adjustments, then they could've done. But they didn't need to. That was all done with a 5.5Kw/H system.

You'd be surprised how well solar hot water works. It just depends on the type of system you get. Again with battery backup, you won't need to worry.

- We are planning to insulate the slab, but have not gotten as far as deciding what product we would use, are there several different products like the one you described? We do plan to have polished concrete flooring throughout the entire house – with the possible exception of bedrooms on the south, if absolutely necessary they will have carpet.

I know it's probably more expensive, but I would recommend the Kingspan K3 Floorboards. It is a brilliant product and I recommend it to be used in all my jobs.

The effect it has on an energy rating is massive. Depending on the layout and orientation of the house, just by adding slab insulation, I have noticed an increase of almost a full star difference in the rating. So that's from 6 star compliance, to 7 star above average.

Here is the product site:

https://www.kingspan.com/au/en-au/products-brands/insulation/insulation-boards/kooltherm-k3-floorboard

- We will also be aiming to have the optimal amount of glazing for solar gain (and prevention of heat loss). I still haven’t worked out why I can’t upload a picture of our plans, but will do ASAP as we would love to hear feedback on our plan.

As for the layout, you just need be mindful of window sizes and orientation. If you have the time before you build to play around with a few different variations of your plans, it might be a good idea, as just by changing a couple of small things, it can give you large benefits. One of the main focuses I have with my business is to help people such as yourself utilise the energy rating software to make small changes at the design stage, instead of just using such a powerful tool at the building permit stage. By then it's too late to make any significant changes. Just keep that in mind. It's a small price to pay to know that your house is going to be as energy efficient as it can be.

If you want to, feel free to email me the plans and I can give them a quick look for you. Just to give you some quick advice on them.

Giuliano

green design & consulting

- Yes, hoping we won’t need heating/cooling aids, but as I mentioned above, other new, passive-designed houses in our area have required heating (although, they don’t have full slab insulation, as suggested by Guiliano above). How do others, in our climate, successfully cook, heat and have hot water in an off grid home?

Smart design will negate the need for a lot of heating and cooling. Well, that mixed with smart material choice. As for the ability to heat, cook and have hot water, I again come back to a good battery set up. As long as you have a decent solar set up (4.5 - 5.5Kw or more). With that you can buy any normal household appliance and use it. You needn't worry about having to buy an item that can only be used a certain way, which generally increases the price of it (Like the wood fired cooker). Then there is no need to be connected to the grid at all, and you can be on your way to being completely self sustainable. (One of my all time wishes)

- Yes, the cost of hydronic slab heating system is something that has driven us to look for other options. We were aiming to have a woodfired stove multitasking as our source of hot water (secondary to solar hot water), cooking and floor heating – but $30K uninstalled is a bit much. Is there are more effective way to heat a house with a woodfired oven? Are radiators the only option? (I’m not super keen on their appearance or having to dust them).

With that cost, you would be able to have a pretty darn good battery setup that will allow you to run aircon and normal heaters without too much fuss. I can't push batteries enough. And the more that people invest in them, the cheaper they become, so when it does come time to eventually replace them, they will be even cheaper again. As far as the actual heating goes, I would probably lean more towards heat pump technology. They have a low running cost with low greenhouse gas emissions.

- We plan to have a 5kW solar system and will only have bottled gas for some cooking, so that we can boil the kettle/cook in summer without having to light a fire. Now we are wondering if a larger solar system would meet some more of our needs? At the risk of revealing how little I really know about all of this(!), I have to ask, are there electric cooking options that can be run by solar power? How large would a solar system need to be for this?

As I've mentioned previously, there was that house I visited a while ago that had no form of gas whatsoever and were able to cook, heat the home as well as do all the normal things that any household does, purely because they invested in batteries to go with their 5.5KW solar set up. (Yes, there I go again... Batteries). Once you install a solar system, you'll need an inverter to convert it to the correct current - From DC to AC. Then all normal appliances run as if you were connected to the grid.

- At this stage, we have kitchen/dining/living, master bedroom and ensuite, and 'outdoor room' all facing north. We have 70 acres, so there are no concerns about neighbours or trees impeding on a passive orientation. Is there a way to design a floor plan/roofline which would provide passive solar heating of rooms on the south?

The rooms you want to keep to the south are your bedrooms (or so they say). Unfortunately as we don't get any sun from the south, there's not a great deal that you can do to utilise the sun there. The other work around is to put your utility rooms there. Bathrooms, WC, Laundry, Storage and the like. That way it should have a more positive effect on your rating.

Giuliano

green design & consulting

Guiliano, thanks for your detailed reply.

I'm so sorry that I didn't give more detail in my initial post. I assumed that by saying we would be 'off grid', others would automatically realise that we would be having batteries and wouldn't be feeding anything back into the grid. But I realise some people possibly use the term 'off grid' to mean many things.
That's great to hear that there's a chance we wouldn't need gas at all and likely wouldn't need to chop wood either! Where was the home that ran solely on solar? Either we don't have enough sun where we live (high chance of this) or the people my husband has spoken to must not be up with the latest technology. Despite being an electrician, my husband was still under the impression that we would not be able to rely almost completely on solar power and batteries (even with an efficient home as possible).
We don't have any utilities connected to our property at all. Getting the power connected would cost us as much as a complete solar power system and we don't have any option but to catch our own rainwater and deal with our own waste (probably a worm farm composting septic system, if our council allows us - they're notoriously difficult). We obviously have the same desire to live as self sufficiently as we can :)
We have read a bit about heat pumps and want to learn more. Are they likely to work in a coastal area (Southwest Vic) where the average minimum temp in winter is only about 6 degrees celcius?
We are planning to purchase an evacuated tube solar hot water system. Is this type the best and would we be likely to need a booster of some sort if we don't get much sun?

Thanks for your kind offer, I will get in contact with a copy of our plans.

Cheers

Jess

Jess

Some people say off grid, however they are still connected to town power, however as the energy they create outweighs the energy they use, they still refer to themselves as being off grid.

As for relying completely on solar power, it does depend on a lot of things. The average amount of sun you get, the size of the solar system that you install, and the storage capacity of the batteries that you have. I do have someone here in Melbourne that can help with that information as well if you need it.

To be able to solely run off rain water and batteries as well as a self composting septic system is my dream. I would invest heavily in an oversized rain water system. If someone recommends all you need is 10000 Gallons, then get 15000. It's better to "future proof" yourself rather than have the worries later on. With the way the weather is changing at the moment, don't be surprised to see what were once areas with a high rainfall soon have droughts. (I know climate change is a somewhat political trouble maker, but I firmly believe in it).

As for the waste management system, you could look at envirocycle's or biocycle's. I lived in a house up in the gold coast hinterland a number of years ago that had a biocycle unit. The only concern was you had to watch what you put in your drains. Anything that had a high chemical component and you would need to use a tablet to balance out the levels for the biocycle. Well that's what I was told at the time and to be honesty, I haven't had much more thought about it since then.

There are heat pumps out there that will work in sub 0 temperatures, however its best to consult with a heat pump specialist who can advise you on which will run better for your climate. They may tell you that the efficiency of a particular heat pump will be extremely low and it may be better to use an electric assist to heat the place. However they may advise of a heat pump will be perfect for your location. I personally don't see an issue if its still around 6 degrees

As for the solar hot water system, I have a pdf file that I can send you that may give you some insight into which is better suited for you.

You can find my contact number and email on my business page here on Houzz. Please include the best contact details for youself as well.

I look forward to you hearing from you.

Giuliano

green design & consulting

As Australias largest supplier of hydronic heating, we have been providing Australian homes with stylish, safe and comfortable hydronic heating and cooling solutions. As exclusive stockists of an extensive range of premium products, we ensure that all homes can enjoy the benefits of a low carbon, energy efficient system.

We have just released an industry leading guide on Underfloor Heating, that contains information for both homeowners and installers, I believe the content within would be the perfect for many commenters on this post.

If you're unsure on how to proceed with your project I recommend you take full advantage of our personalised consultation service, available for both homeowners and installers. Using the latest design software and coupled with the expertise of our Customer Service Team, you can rest easy knowing that we’ll design a bespoke solution that delivers superior comfort that is also environmentally friendly and energy efficient.

If you would like a copy please email me on sophieo@huntheat.com.au, alternatively head to our blog to download a copy: Hunt Heating Blog

Here’s my two bits worth - from a users perspective. We’ve lived in a houses, neither of which had the full benefit of full environmentally friendly design and both in fairly harsh inland climates - cold winters, hot summers. Had tiles + infloor heating (off-peak electricity), really nice but really expensive but they are probably better designed now as that was a fairly old installation. Other house, a mix of timber and polished concrete with Stanley donard Slow combustion (dual fuel) cooker, heating water (with electricity boost which you need for the hot water when it was really cold) and hydronic panels throughout house. The panels were good and like a heated floor, give a nice radiant heat, not just hot air. biggest downside was that you needed to be there to keep the fires going so don't skimp on the size of the firebox. and as someone has said, dragging wood into your house does generate its own level of mess so a design that minimises the need to walk timber in and ash out through the house is a bonus. remember tiles/concrete is always hard underfoot and if you add to this cold in winter this its not pleasant. Whatever you choose, don't let anyone talk you out of installing in floor heating in your bathroom. This is the one non-negotiable option for mine.

Re. Cooling, if you've got water and live in a lower humidity environment, I don't think you can go past evaporative air cooling - its gentle and allows you to leave things open a bit so at least you aren't chasing people to close doors and windows all the time, and you put some moisture back in the air which is kinda nice when everything around is dry and hot.

Last thing, get a log splitter if you haven't got one already :)

I'm currently looking into installing a small hydronic system in my bathroom of about 8m² powered by a small nectar combustion heater from a flue hot water jacket. Does anyone have an advice?