The negative consequences of energy efficiency policy

air-conditioning-typesI’m going to touch on a couple of things in this post – a recently formed research group out of the US about how people impact energy efficiency and also how house energy efficiency policy such as Basix is increasing the use of air conditioning.

First up the impact of people
Researchers from the MIT Energy Initiative (MITEI) and University of California at Berkeley’s Haas School of Business have teamed up to create a new interdisciplinary group called E2e to tackle the often found shortfall between what the engineers and policy makers calculate energy savings to be and the reality of what happens.

Take a recent program in the US, that will sound familiar to people in NSW, a policy was created to provide grants to systematically remove the old inefficient air conditioning units from housing and replace them with new air conditioning units. The theory was that it would reduce the energy consumption for the air conditioning units – logically that makes sense a new efficient air conditioner uses less energy than an old inefficient unit when it is turned on. The reality was that the occupants liked the fact that it cost them less to run, the units were less noisy and more reliable and the overall energy consumption went up.

These types of problems are exactly what E2e has been setup to tackle. Keep an eye on their research – it will be extremely beneficial.

Now our homegrown problem
Basix is a NSW rating system that is used to assess the overall environmental performance of new houses and apartments in NSW, Australia.

The Basix calculation includes not only the construction of the house or apartment but also the type of air conditioning unit that you put in. If you put in a more efficient air conditioning unit you are allowed to have a slightly poorer performing facade – makes sense.

Except when you don’t put in an air conditioning unit. If you don’t put one in then the calculator assumes the worst type of air conditioning which means you have to install a better facade. Which makes sense because you don’t know what type of air conditioning unit someone might install in the future and you should allow for worst case.

Makes sense so far.

Well not quite. What is happening at the construction stage is that it is cheaper to install an air conditioning unit and a poorer performing facade than it is to not install an air conditioning unit because of the default worst case calculation in the Basix tool.

So what is happening is that before Basix came in the default was to NOT install air conditioning in apartments but offer it as a buyer option. Since Basix the ‘default worst case calculation’ has meant that the default is that every new apartment has an air conditioning unit installed for free.

If you have an air conditioner already installed in your new apartment you are more likely to use it regardless of how well the passive systems are designed – its just human nature. The air conditioning unit will be a new high efficiency unit which means the running cost will be low so you will use it more often – its just human nature.

The consequence of the policy – certainly more air conditioning units installed in homes in Australia and very likely more energy used by air conditioning not less!

Is it the fault of Basix or NSW Planning, no, it was an unforeseen negative consequence of the policy. Should they change it, yes absolutely it will have no negative consequence on energy consumption it may even have a positive consequence.

7 Comments on “The negative consequences of energy efficiency policy”

  1. The Californian experience with energy efficient AC systems is a perfect illustration of what researchers have for a long time called the “rebound effect” (aka “comfort creep”). We’ve seen this happen all over the world when efficiency improvements perversely increase energy consumption – because residents drive their AC or heating equipment harder than before to improve their comfort levels. Other examples come from the UK and even Downunder in Australia and New Zealand where government investments in ceiling insulation have produced energy consumption outcomes that completely contradict policy intentions.

    The moral of the story is that rising comfort expectations are more powerful than energy savings (at current energy tariff levels at least).

    • Thanks for the comment Richard. I hope that the awesome work you are doing at the University of Sydney can be fed into policy creation some day.

  2. Simon, hoping you can help me get my head around this… I don’t get why you would be allowed to get away with building a poorer performing facade if you put in a high effiiency AC. Is it to do with the overall construction costs of doing both? A high efficiency AC and a good performing facade should lead to lower energy consumption because less energy will be required to maintain the internal comfort level. In fact that would apply regardless of whether the AC is low or high efficiency… I can’t help feeling I’ve missed something obvious (other than the performance of the facade shouldn’t be linked to the installation of AC!)

    • Colin, Your response highlights the issues with standardised energy efficiency tools. BASIX is a trade-off tool to achieve a set energy reduction target compared to a basecase development. There are two options in the BASIX tool associated with heating and cooling to improve the BASIX energy score.
      The first option is to reduce the thermal heating and cooling loads by providing improved passive design and an improved façade. The loads are determined through thermal modelling inline with the House Energy Rating Scheme. The HERs requirements in NSW are significantly lower than other states, as BASIX allows other energy efficiency options to trade-off with comfort.
      The second option in BASIX to reduce A/C consumption is to install an air conditioning system. If no A/C system is specified BASIX assumes that a low efficiency system will be installed. This means an easy way to make big energy ‘reductions’ in BASIX is to install an A/C system.
      Particularly in multi-unit residential, as a construction cost cutting exercise, AC can be installed to achieve the BASIX energy target, as a trade-off to a better performing façade.

  3. Pingback: How to be green – drive a rust bucket « SIMON WILD

  4. Hi Simon

    Great blog post, wish i had this information when I went up against BASIX when I was planning the conversion of an existing building into a home ie converting a church. As I wasn’t able to get close to the thermal comfort targets set NATHERS 4.24, I was unmodified 2.54 stars. The church is located in a “remoteish” town in North Western NSW, I met summer cooling loads unmodified but wasn’t close for winter heating loads. I tried to explain that wood is cheap and renewable and VERY plentiful so heating isn’t the issue, cooling in summer when the temperature is over 45c is the issue. Short story is I am unable to install an air conditioner as I didn’t meet the thermal requirements, below is from the email response i was given.

    “The energy score is achieving a slightly better result than required but we are using this over compliance in energy to help counter the Thermal Comfort, therefore no changes can be made to the energy section that will result in a score drop.”

    So if i had your take on it I may have been able to argue for an efficient air conditioner, as it is we have one installed that I will have to remove for the final inspection, only to have it installed again….


    • Hi Troy,

      That does sound unusual. Generally if you do not meet either of the NatHERs heating or cooling requirements, then you will not get a BASIX pass score for thermal comfort,

      The only thing I can think is that as it is a change of use you would have been required to complete the BASIX certification as a ‘new dwelling’ rather than using the BASIX ‘alterations’ tool. As a ‘change of use’ project, if you weren’t altering the facade or glazing, you may have been given a thermal comfort concession for the heating loads?

      If this is the case and the heating requirements are high as you suggest (ie exceeding the BASIX target) then it is likely, even with a high efficiency air conditioner, that the energy required to heat the home would be too high to achieve the required BASIX score.


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