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Emilis Prelgauskas architect is a trained 'FirstRate' energy efficiency assessor (HE014) in accordance with the requirements of the South Australian housing regulations, and prepares 4 Star compliance certificates for housing submissions for approval.

Emilis Prelgauskas architect is a known energy efficiency expert for housing. He can prepare individual technical expert opinion on energy efficiency for housing.

He is part of the expert opinion panel accredited for housing submission for approval after Jan 1 2003.

Mandatory requirement for housing in South Australia


Proving energy efficiency

initiatives by this practice in 2003

Energy Efficiency Star Band The regulatory approach to energy efficiency is to measure compliance by non dimensional means: ie 'Stars'.



At www.aue.sa.on.net the positioning of this Star band in relation to the full energy efficiency spectrum is explored.
This shows that high energy efficient buildings position beyond the upper end of the Star band.

This leads to problems for best practice energy efficiency buildings where these don't rate well in the Star band because they achieve outcomes by other means.

In particular, 'free running' buildings avoid mechanical air conditioning where the Star band gives no credit for the reduced energy use by using passive comfort systems.

Thus, best practice buildings are best measured on objective performance measure. However, the Star band has no such directly comparable objective energy use measure.

During 2003 this practice in its primary R&D role carried out a project to both:
- post occupancy measure existing operating high energy efficiency houses
- impute comparable energy use measures from the Star band method of energy efficiency compliance.

This work was done for the South Australian context of climate and building performance.

Existing houses were measured where:-
- retrofit of existing house with passive comfort system features showed a reduced energy use in metered energy supply
- new houses with passive comfort systems measured energy use from public supply
- new houses with stand alone renewable energy systems have attributed maximum energy use equal to the generation system output
- new houses with on-site and mains connection have metered energy generation, use and surplus export

This practice had the willing assistance by the homeowners of about 2 dozen projects from this practice, and a number of other similarly positioned architects were approached to contribute.

The Star band was assessed against:-
- known average energy use by traditional housing in Adelaide
- energy use attributed by the computer software
- inherent limitations of the software

In addition the contribution of passive comfort systems, occupant management and greenhouse abatement measures were canvassed.

All these elements are published in the folder -

'performance outcomes: free running buildings achieving energy efficiency'

This is the base source for evidence to assess the expected performance of new house projects by the 'expert opinion' method.

In August 2003, the folder received the 'R&D Award' at the Sydney Green Buildings Conference.



energy efficiency

mandatory requirement for housing in South Australia

In South Australia, the first regulatory mandatory requirements for housing energy efficiency are due to begin on Jan 1 2003. by addition to the South Australian provisions of the Building Code of Australia under section SA 2.   The core objective stated there is "to minimise greenhouse emissions".


In the preceding decades a number of efforts toward encouraging energy efficiency in housing have been instigated in various parts of Australia.

Through the CSIRO, Prof John Ballinger, SEDA, SECV and others a number of computer simulation based energy efficiency modelling and rating methods have been developed over the years. SEDA has encouraged SmartHomes as a rating system in Councils in NSW. ACT, Victoria have operated the beginnings of mandatory rating systems. AMCORD includes basic energy efficiency advice in its residential guidelines. The Australian Greenhouse Office has developed the 'Your Home' kit. Industry has been encouraged to voluntarily incorporate energy efficiency into volume housing as standard.

Meanwhile in South Australia

Planning SA developed a guideline Minister's Specification SA 2.1 for minimum insulation standards. (which this practice contributed to through the Planning SA committee structure) A number of urban development areas including Northfield and Mawson Lakes have used checklists intended to encourage energy efficiency. Some Council planning regulations have intimated emphasis to building energy efficiency.

And throughout, a number of architects have been developing cutting edge projects. These now form a large but dispersed body of operating evidence about the benefits of energy efficient housing.

But in the end, regulation has been introduced. Its goal is to at least require a minimum raising of energy efficiency levels, particularly in volume housing, from non existent to at least minimal.

The deemed to comply requirement is to achieve a 4 Star certificate rated under either NatHERS, or FirstRate, the computer systems noted above. The submitted rating certificate is to be prepared by an accredited assessor. (This practice is one of these assessors)

This architect's review

The past efforts have had varied outcomes.

Council planning regulations have been poorly drafted. Such requirements as for 'living rooms must face north, bedrooms must face south' have completely missed the point. Such prescriptive requirements don't suit each site, and obstruct innovation.

Checklists have a poor history, both because of the variability of persons filling them in in contrast to the accredited assessor approach noted above, and these also being prescriptive about what they rate as contributing to energy efficiency.

Even the applicability of computer simulation is variable, because of the factors described below.

Critique of computer simulation

As expanded on below, energy efficiency is a complex issue. However, rating systems try to be easy to use, not too onerous in their outcomes, and to make assumptions and simplifications to achieve a rating tool at all.

Critics of the tools point to where the tool rating doesn't match experience in the real world, including:- - small houses rated as less energy efficient than the same construction of a large house, because of algorithms that relate wall area to floor area - that winter heating energy loads exceed cooling loads even in hot dry and tropical climate - where a location is attributed climate parameters different to real experience ('Melbourne' climate for the Adelaide Hills, a temperate climate for Murray Mallee)

And when applying the rating tool, it is fascinating to watch a rating change to similar degree for some little thing (the choice of window frame material) as it does for a major change (wall construction changed from cavity brick to straw bale). Again, a mismatch to real world experience.

Having said all that, rating tools can be useful. As long as the building being rated is using assumptions similar to those embedded in the rating tool. This means mainly volume housing using mass construction practices. In particular brick veneer where insulation can be stuffed into walls and ceilings to change the building performance.

But we need to never lose sight of the fact that rating tools:- - do not measure greenhouse emissions - do not measure energy use

Rating tools do nothing more than accumulate 'Stars'.

And yet our claimed goal is to minimise greenhouse gas emissions. Which is more effectively achieved by design of housing specifically suiting its individual site. While we can measure greenhouse gas emissions (carbon tonnes/annum), and energy use (kWhr or MJ), 'stars' are some magical non dimensional number where relationship to measurables above is yet to be established.

One off houses

The difficulty in using such generic tools for rating houses designed specifically for individual sites has been known for many years. Poor 'ratings' for well known architects and award winning buildings have alerted us to the limitations of these tools. (to have Glen Murcutt passive energy efficient houses, and award winners like John Maitland's Norton Summit house rate 0 or 1 star points to the tool failing, not the houses, which have been validated by post occupancy testing).

For a presentation by Planning SA at the 2002 SA state building surveyor's conference, several of my practice's houses were independently rated.

The houses used are 'Redcone' and 'Davelea' , described separately on this web site. I had rated them with my beta version FirstRate previously, and they achieved 0 and 4 stars respectively. Yet in the real world Redcone is greenhouse neutral, its energy demand being supplied by a 0.24kW renewable energy system. And Davelea is a carbon credit building, where the excess from the 2.5kW renewable energy system is exported to the mains as Green Power. (the terms 'greenhouse neutral' and 'carbon credit' are described below).

Jim Woolcock of houseenergyrating.com measured the houses independently under NatHERS, the more detailed of the rating systems. Redcone achieved 1 star, Davelea 5 stars.

That suggests that Redcone emits 12 carbon tonnes of CO2/annum, and Davelea emits 5 carbon tonnes/annum. Yet, in the real world Redcone emits 0 greenhouse gases, and Davelea develops Renewable Energy Certificate credits.

Clearly, the rating tools get it massively wrong when applied to one off houses for specific sites; in particular on projects by architects achieving energy efficiency by design.

The complexities of energy efficiency

This whole web site is devoted to sustainable outcomes in buildings. Within this topic, energy efficiency is only one contributing factor.

This web site deals fleetingly with the classic 'passive solar' approach to energy efficient building design both because it is dealt with in all the sources noted above, it is the basis of the rating tools, and because frankly we've moved on to more sophisticated ways of achieving real energy efficiency passively as is detailed throughout this web site.

Energy efficiency can be characterised as being contributed to by:- - site factors - renewable inputs - building envelope - passive and low energy factors - occupant behaviour

Site factors include the slope, geology, climate and as well the vegetation including its wood lot as fuel source and its carbon sink capacity in absorbing CO2 in re-growth together contribute to reducing greenhouse emissions. The last can be woodlot, plantation (including waste water disposal areas) and protected old growth forest.

Renewables deliver energy with-in the development without greenhouse emissions. Such systems include photovoltaic, wind turbine, mini-hydro and wood fuel linked to woodlot. Rating tools of course assume all fuel delivery to be from fossil fuel generation.

Building envelope issues are dealt with in 'passive solar', 'climate response' as well as being the basis of the rating tools. Materials, construction form and extents define heat in and out flow. Unfortunately the rating tools give average outcomes in their assessment, whereas the architect in one off designs can 'ramp up' the achieved performance by clever application of form, material and construction detail. see Paul F. Downton's Christie Walk project described in the Australian Greeenhouse Office publications, and his Ecopolis web site.

Passive and low energy features (as detailed throughout this web site) mean comfort modification at a fraction of the energy use assumed by rating tools.

John Maitland says his clients drive their houses like a yacht. My houses are geared to operate efficiently more intrinsically, but the comment is still true. Occupant behaviour is a major determinant to the success of the energy efficiency potential of the house. Rating tools assume a standard behaviour of a mechanically comfort conditioned building. What this doesn't allow for is the energy penalty where occupants leave equipment on even when the house is unoccupied, and the house is already at comfort levels passively. Nor do these tools allow for the different comfort levels accepted by people in differing climates, their activity patterns and the relationship between temperature, humidity and air flow rates. These things are known through occupancy studies including those by Prof Terry Williamson and others, and are given credence in design programs including Ecotect.

While it is possible to have regard to the interrelationships of all these things in individual building design processes; the simplifications and assumptions in rating tools means that many of the subtleties and cross linkages are lost, and the ratings undervalue passive outcomes.

Defining the terms

A 'greenhouse neutral' house is one where the energy in, the energy used, the greenhouse emissions and the greenhouse gas absorptions on site all together come out to zero.

A 'carbon credit' building extends this high level of performance where renewable production and the area of carbon sink results in export of greenhouse credit to someone else who is a greenhouse gas debitor. The latter becomes more important as Kyoto protocol standards kick in in the future. Already carbon sink values are being investigated federally, industry is buying into plantations against future greenhouse obligations, and the federal Office of Renewable Energy Regulator is producing certificates for renewable energy installations for an emerging trading stock market.

Our houses as carbon credit buildings are little clean power stations, and can now be accredited as such. Not just in selling outgoing electricity, or its enhanced value as Green Power, but also through the economic value credited to the permanent production infrastructure.

Full Energy Efficiency Spectrum


So how do we rate

The chart above clearly shows that to rate a greenhouse neutral or carbon credit building as even '5 Star' is a massive insult to those buildings. And that it is futile to rate houses at the high performance end of energy efficiency performance within a system that stops at 5 Stars.

'Compliance' methods which need to be used in such circumstances so that other elements incorporated in such buildings are credited include independent validation by an external person or an expert panel.

The problems with this approach surround the issues where:- - the architect who designs the building for performance ought be responsible for the performance - the architect who innovates needs flexibility in drawing on the 5 areas of energy efficiency contribution described above - the architect who is the person most knowledgable ought have their analysis accepted

So there is an impetus for the architect to provide the accreditation in lieu of a 4 star compliance certificate.

So this practice has developed a pro-forma architect report which describes the energy efficiency of the development proposal, relates it to known performance of precedents, and positions the development application within the energy efficiency spectrum charted above.

There will be those who will wish to 'require' cutting edge house applications to conform to the deemed to comply star rating process. This architect's response to that is clearly stated at the head of this section.

There will be those who will wish to 'require' cutting edge houses to be 'de-rated' down to 5 star performance. That isn't going to happen. It is the last 20 years of such one off buildings being built and operated that has finally seen regulation for minimum requirements. That on-going development will be the driver toward further mandatory requirements in later years.

There will be those who will wish to 'require' third party 'validation'. Problems have already been demonstrated in that approach on other building elements such as footing design, framework, bracing and trussing design. Where parts of an integral building design by the architect are removed to outside parties doing elements of the building, confusion arises as to who is reponsible for the performance of which bit. And 'elemental analysis' never gives performance credit to a fully integrated solution. Calculating each part doesn't reflect the mutually interactive results achieved.

Just as an elemental analysis of one of this practice's framed structures (acting as a single semi-monocoque structure) by a building surveyor neglected to acknowledge the mutual support of floor, wall, ceiling, roof and truss chord bracing in together resisting uplift; rather than floor bearers acting alone. So this architect's 'architect report' in lieu of compliance certificate stands as a viable method of compliance on the grounds of this architect's expert status, and as the person responsible for the achieved performance. External validation muddies the issue by introducing confusion as to who is responsible; perhaps the building surveyor questioning the performance, the employer Council, or their nominee?

In a similar vein there are going to be those who will seek to 'require' deemed to comply certificate on the grounds that future house occupiers will not accept the same comfort standard as used by the original clients for a passive energy efficient house. Practical experience over the last 2 decades shows that while consumers may buy second hand volume housing and then add energy consuming comfort systems; this does not occur with passive energy efficient houses. Passive energy efficient houses are clearly what they are to an intending purchaser. Past experience is that re-sale is to only the interested market segment. While 20 years ago this was a specialist niche; today the re-sale is to a more knowledge market segment of house buyers valuing passive comfort and its low operating costs. Thus future occupants of passive energy efficient houses do adopt the same standards as the existing owners. A passive energy efficient house is less likely to become energy demanding than conventional housing built only to a minimum energy efficiency rating.

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