Mandatory Solar Power For New Australian Homes?

A report released last week recommends solar panels or other renewables be compulsory for new homes built in Australia; saying such a measure would help slash energy bills, network investment and emissions.

The consultation period for proposed changes to NCC 20191 was recently announced by the Australian Building Codes Board.

The Australian Sustainable Built Environment Council (ASBEC) and ClimateWorks Australia says while the NCC 2019 Public Comment Draft includes proposed improvements relating to non-residential energy requirements, there is no proposal to beef up the required level of energy efficiency for homes.

“The energy requirements in the Building Code were last updated in 2010 and are next due to be updated in 2019,” said Suzanne Toumbourou, ASBEC’s Executive Director. “There is currently no plan to strengthen standards for residential buildings in this Code update. Further delay means that we will be building to 2010 standards all the way to 2022, locking in higher emissions and energy costs.”

Introducing Renewable Energy Requirements

Among its recommendations, analysis carried out by the organisations indicates there’s a case for the introduction of renewable energy requirements for new homes in the Code. While the report’s focus is on solar power systems, it says incorporating renewables doesn’t need to be limited to PV or any particular technology.

It also acknowledges there are a number of issues with incorporating such requirements.

  • In cases where rooftop solar isn’t possible, exemptions or allowances for these households to purchase near-site or off-site renewable energy could be made.
  • Appropriate finance mechanisms to help reduce the burden of upfront capital costs should be put in place.
  • Grid integration issues would need to be addressed (not considered as part of the analysis).

.. But Energy Efficiency First

While the high-level analysis shows solar panels are already more cost-effective than most of the energy efficiency opportunities identified, the report stresses improving other aspects of energy efficiency first is a more critical issue. This would also mean smaller renewable energy systems would be required, reducing the cost of investment.

The most cost-effective energy efficiency opportunities identified included:

  • Reducing air leakage
  • Increasing roof insulation
  • Use of ceiling fans in in warm and hot climates

The report says the cost-effective measures could reduce energy consumption for heating and cooling by an estimated 28 to 51 per cent across a range of housing types and locations..

Reduced Energy Bills, Emissions And Network Investment

ABSEC and ClimateWorks Australia say their proposed changes would not only save households on energy costs, they could also save an estimated $1.2 billion to 2050 through avoided and deferred electricity network investments.

With the next opportunity to update the Code not until 2022, they same the time to act is now.

“With half a million homes projected to be built between 2019 and 2022, delaying improved energy standards by just three years would lock in an estimated $1.1 billion in unnecessary household energy bills, and 3 million tonnes of additional emissions by 2050.”

“The Bottom Line – household impacts of delaying improved energy requirements in the Building Code report,” can be downloaded here (PDF).

By the way, if you already have solar panels from your rooftop and want to reduce your electricity bills further, check out Finn’s energy efficiency tips.


  1. The NCC is an initiative of the Council of Australian Governments (COAG), developed to incorporate all on-site building and plumbing requirements into a single code.

About Michael Bloch

Michael caught the solar power bug after purchasing components to cobble together a small off-grid PV system in 2008. He's been reporting on Australian and international solar energy news ever since.


  1. It is about time that all new dwellings would be mandatorily required to include such things as rooftop photovoltaic systems (something like a minimum of 1 kW of generating capacity per bedroom), and, battery storage (something like a minimum of 2kW output capacity and 2kWh usable storage capacity, per bedroom), with backup storage to provide (for electricity grid connections) for electricity grid supply failures. Where people have medicines that need to be kept refrigerated, like insulin, backup battery storage is a necessity. And, as Australiaq no longer has an effective landline telecommunications system (it shuts down, when the electricity supply fails), and does not have a reliable cellphone telecommunications system, backup battery storage is even more imporatant.

    But, consumer law also needs to be strengthened, so that warranties on photovoltaic systems, are enforceable, and, so that warranties on photovoltaic systems and their components, have a minimum parts and labour coverage, of ten years.

    Rooftop photovoltaic systems that only last for 3-4 years, and which effectively do not have any worthwhile warranty, are not very good, and, should not be allowed.

    Also, double glazing on all windows in all new buildings, should be mandatory, as should roofing insulation of at least R3, and, complete temperature transfer assessment of all new buildings, should be mandatory, to minimise heat transfers between inside the buildings and outside the buildings. And, this paragraph should also apply to commercial buildings, both new and existing, including, but not limited to, office buidings, and commercial accommodation buildings, such as hotels, motels, etc.

    And, all of these measures should apply to rental dwellings – both new and existing.

    • The Building Code of Australia requires all new houses to meet minimum standards of thermal comfort (insulation, glazing,etc). NSW has its own scheme, BASIX, which combines thermal comfort, water efficiency & appliance energy efficiency into one online tool. Complying with thermal comfort always requires insulation & sometimes double glazing. The water section has many options which contribute towards compliance but in practice nearly all new houses need a rainwater tank. The energy section also has many options, including PV systems and, given that they are relatively cheap these days & pay for themselves, they are becoming more common as an easy means to comply.

  2. I think it’s a good idea and a step in the right direction but yet again the time of use issue raises it’s ugly head as most of us I’m not there during daylight hours as we are at work. Plus as you yourself have said Finn batteries are far too expensive at the moment for the masses. Plus the obvious investment in something that stays on the roof for 30 years however the average Australian moves every 7.2 years. There are other issues that you’ve pointed out such as the technology not everybody knows the ins and outs of solar, then there’s the ongoing monitoring is it working is it working effectively or like most people put it down so I’ll the must have been some clouds however the fact that their panels have malfunctioned or the inverter is not working correctly they just down now. Who do they trust to install it? All in all I think for many people it’s just far too much hassle.
    As written by Brett above this should also apply to commercial buildings in fact this is far more important but we put solar on commercial buildings as commercial buildings are operated during sunlight hours and 99 of them have empty roofs.
    Not to mention we could be even more sensible and install water tanks at the time of building!!! Imagine….

    • Some good points raised here, I might offer a different viewpoint on some of them.

      The time-of-use conundrum is valid if we consider the house occupants, but I see the goal as more holistic. As we add incrementally to the population, it would make sense to use the opportunity to add incrementally to the power supply by using every new roof available. This works if the city’s power demand is largely during daylight hours, whether or not the occupant is home. Payback time and occupancy time should then be worn by the house rather than the owner.

      I’d also like to see a move towards simplified monitoring. Having panel-by-panel, minute-by-minute information becomes possible with fancy microinverter systems but all of that detailed data has little value unless decisions can be made with it. In all but the most boutique of cases, this data isn’t really necessary for any practical decision. I could check my total kWh every few months, compare it with an expected value for my system size and location, and know if it’s still working properly. This is all that’s required for most owners, many of whom are not necessarily enthusiasts.

  3. Given the current increasingly dire situation vis-a-vis water both outside Australia (eg Capetown) and within Australia (eg Perth, Adelaide) it seems a rather narrow view to simply talk about energy efficiency on its own. As already mentioned, compulsory water (including rain) harvesting and storage should also be instituted. I live in Perth, in a mid ’70s brick and tile bungalow, and have 3.2 kW of rooftop solar panels and a medium size battery bank (about 11 kWh) with ceiling space insulation and double glazing all round. My DG included holes in two doors to take an exhaust tube for a wheel around refrigerated air cooler and on a “good” day (ie sunny and humid) the A/C generates up to 10 litres of condensate per day. I put this through a multi stage filter system which includes reverse osmosis and ultra violet sterilisation. I have 3,300 litres of rainwater tankage plus several 75 litre bins to act as temporary overflow storage when the rain really lets loose. (I use the bin water first and as each bin empties I can stack them one inside the other to reduce the storage footprint.)

    Depending upon conditions, I can run the A/C when the house is empty and convert my excess solar power into water – selling excess power to the grid nets me about $0.07 per kWh, and I’d rather have the water than the money. (However, even with the A/C running, I’m STILL able to export a small amount of power).

    Lastly, at Easter 2017, I purchased an electric scooter (full size, eg like a Vespa) which can convert excess power into savings on petrol for my motorcycle. Whilst I can’t use the scoot for EVERY trip, nevertheless it’s done just over 3,000 km in 10 months. At today’s petrol price that equates to saving roughly $160 (not to mention emissions from carbon powered generation foregone). The battery can be fully recharged from a standard 240 volt AC power point and will take about 3 hours. It can either recharge from the house batteries overnight or from the solar panels during the day.

    • Rain water tanks which collect roof collection are mandatory in many new developments in NSW at least. I’m not 100% certain whether it’s required due to the current CDC or whether its the individual council’s DCP, but all houses my family/friends/coworkers have built in NSW in the past 3 years have had to include rainwater tanks.

  4. Whether or not mandatory solar on new housing may be a good idea, you can’t forget that anything that involves bureaucracy and is mandatory will always become more expensive over time. Mandatory items also tend to have little real competition in purchase price. And any ‘savings’ will either not eventuate or simply wither away as the bureaucracy grows and still needs to feed off consumers and taxpayers…

    Commercial users are already trying to leave the grid or minimise grid usage where they can. Make it mandatory to have commercial solar and the grid owners/bureaucracy will need to either (a) increase daily supply or other charges to keep the aggregate commercial power bill at current levels or (b) spread the $ amount no longer available from business over the remaining people still connected – the residential consumer. As large commercial users tend to have friends in high places and legal firms on retainer, the second option of taking more blood from the stone (the residential user) is much more likely.

    If ‘the powers that be’ want $X from their utility investments to feed the general coffer or help fill a budget black hole, then in future they will do what is necessary to continually manipulate the rules of the game to achieve that dollar amount (increase cost per kwh & daily supply charges, add new charges for NOT being grid connected as you still go out in public where power is needed/provided, decrease allowable size of inverters, legislate mandatory access to your roof space and the right to draw power from your battery bank, etc.). When the power producer/wholesaler *is* the bureaucracy and *is* the regulator and *is* the maker-of-rules any appearance of independence is illusory and savings are likely to be short lived. Or perhaps that is just the dystopian future in Western Australia…

  5. Regarding the water problem in WA, as was said many years ago, at the first Water Forum, held in Perth, and, I believe that it was said in a television interview, WA does not have a water shortage problem – WA has a water management problem. Decades ago, the proposal was made to establish the Ord River Pipeline, to supply water from the Ord River to the southern half of WA, but, it was knocked on the head, repeatedly, by the suiccessive anti – CY O’Connor cavemen in the WA parliament, and, the contempt for the water problem iand the people of WA, was summed up by the then premier of WA, Geoff Gallop, who went on television, the night of the day of the WA Water Forum held in Armadale, and saied, effectively, “We do not care what the people of WA have to say – we have already made up our minds to not act to solve the water shortage in lower WA – these Water Forums were only held to spend taxpayers money, to fool the gullible public into thinking that we would take notice of them”.

    As was said then, and, agreed by the public, WA does not have a water shortage. WA has a water management problem, aggravated by a crooked parliament.

    The use of the Ord River water, by the people in that area, to grow crops that should never be grown in Australia, until all of Australia has high (over a metre each year) rainfall, is like Qld, NSW, and Victoria, stealing water from the Murray River.

    The problem is in the management, like the federal economy, and the idiots who regard coal as clean and that regard burning coal to be better fror the environment, than using clean electricity generation.

  6. This proposal should be thought out more as there is an initial cost, running costs and obviously the time of day usage issue. And at this stage batteries in domestic installations are not cost effective and not efficient. If the batteries are used daily and if 30-50% capacity is used then the life of a battery diminishes quickly after about 2 years. Its capacity would also have diminished. Just remember how the performance of your last good mobile phone battery was because the domestic storage battery that is precisely the same.

    • I’m not sure I can see what the problem is. I’ve had my (sealed lead acid) batteries since 2009, supplied by 3.2 kW of rooftop solar panels. For any heavy usage (including recharging my electric vehicle – a scooter) I use the solar power which obviously doesn’t come from the batteries. (Even while charging my vehicle I can be exporting to the grid.) I only use the batteries from dusk until the “off-peak” rate for grid power kicks in at 21:00 hours, and I have programmed the smart charger/ inverter to then maintain their charge, which usually is in the vicinity of 88-90%. Since there are only small appliances being used (clock, TV, fridge etc), the current drawn is about 290-320 watts. My latest power bill tells me that my average daily consumption is 0.9492 kWh, at a cost of $0.63. With over 50 years experience in electronics I fully expect these batteries to last some 12-15 years.

  7. Joe Blake – and, prithee tell, what is the water flow of the Ord River, that you conspicuosly omitted from your information, since your response was to a matter concerning the Ord River?

    It is notable, since you cited the WA Water Corporation, that it is one of the bodies that did everything that it could, to prevent WA from having an adequate water supply.

    • Bret,

      The figures I linked to say what they say. If you have a problem with them, complain to the Water Corporation.

  8. Scott –

    Having panel-by-panel, minute-by-minute information becomes possible with fancy microinverter systems but all of that detailed data has little value unless decisions can be made with it. In all but the most boutique of cases, this data isn’t really necessary for any practical decision.

    From what I understand (and, I accept correction if I am wrong), where monitoring by panel is available, for both microinverter systems, and the SolarEdge systems (that use DC Optimisers, connected to a single inverter), the data is sent into the clouds, where it can be continually monitored by the installation company and/or the components manufacturers, and (supposedly), upon component failure (for example, a panel dying), more or less immediate action can to taken to fix the problem, so, for example, if a microinverter, or a DC Optimiser, or, a panel, or, an electrical connection, is shown to have failed, action can be immediately taken, to arrange for its replacement/repair.

    That is only one of the benefits of continuous per panel monitoring.

    As I said, I accept correction, if I am wrong in this understanding.

    • Thanks Bret,

      I guess that if the data is amalgamated into a large intelligent system where exceptions could be easily detected and remediated then this would have some value. Less so if the onus is on the house owner to do so.

      Nonetheless my thinking includes:

      – Panels and systems are getting cheaper and cheaper
      – The probability of a panel failing totally in service is small
      – The probability of a panel underperforming slightly might be higher, but the consequence of that is likely to be minimal and probably wouldn’t cover the cost of a call-out under a certain threshold level

      I’ve been gathering and storing 5-minute performance data every day for the last ~ 10 years because it’s one of those things I like to do. Most people don’t, and I’d argue most people don’t need to. An occasional health check based on the total per day would probably identify 9 out of 10 systems with performance problems. Detailed diagnosis could follow after simple screening if it’s worthwhile.

      The way I see it micro-inverters have other selling points (e.g. handling shading better), panel-by-panel monitoring more or less comes as a bonus with this – but I would be curious to see how many individual panel problems are identified and rectified over the next 5 years.

      • I’m likewise a collector of data, having a spreadsheet of daily readings from the utilities’ meter going back to 2009. When my system upgraded to having a “smart inverter/ charger” it likewise collected data at 5 minute intervals which I download daily but don’t normally use. However, when a problem arose with my system (involving it disconnecting from the solar panels), I was able to contact the installer’s tech and download the full data set(s) for him to analyse. Further, when the results were pretty inconclusive, I was able to contact him on Skype, and using the “share screen” function, he was able to view the output from the smart charger in real time, and perform a much more detailed analysis with him directing me as to what tests should be done.

        The problem with my system was highlighted when the utility shut the local power off for 8 hours to perform maintenance, and it turned out the likely cause was not having the grid to act as a load when the batteries were fully charged. The simple solution was to turn on the air conditioner which put a load on the system and consumed the excess power.

  9. Making installation of solar mandatory is a typical proscription from yet another organisation determined to tell people how they must live their lives.
    Provide financial incentives – as already happens – and let people decide how they want to spend their money – on solar or not.

  10. “Provide financial incentives – as already happens – and let people decide how they want to spend their money – on solar or not.”

    Quite right.

    A good financial incentive – simply charge an electricity grid connection fee increment of $20,000 (and, of course, index it to keep pace with grid electricity charges), for electricity grid connections, for all new dwellings that do not have rooftop photovoltaic electricity generation systems and storage batteries enough to provide for 12 hours of usage for the dwelling.

    What a brilliant idea – a financial incentive, allowing the owner of the dwelling being built, to then choose whether they want to install adequate photovoltaic electricity generation and battery storage, or, pay the electricity grid connection fee increment of $20,000 (indexed to keep pace with grid electricity charges).

    Yes. That allows people the freedom to choose which option they want to implement.

    Brilliant idea!

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