Market Research to Assess the Proposed Designs for the Nationwide House Energy Rating Scheme Universal Certificate
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Market Research to Assess the Proposed
Designs for the Nationwide House Energy
Rating Scheme Universal Certificate
May 2013
Prepared for:
Residential Buildings Team
Building Energy Efficiency Branch
Department of Climate Change and Energy Efficiency
Level 3, 2 Phillip Law Street
Canberra ACT 2601
Contact: Angie Marlow
Phone: +61 2 6159 6934
Email: angie.marlow@climatechange.gov.au
Prepared by:
Sustainability House
Unit 8/938 South Road
Edwardstown SA 5039
Contact: Sally Thompson
Phone: 1300 308 525
Fax: +61 8 8297 7814
Email: research@sustainabilityhouse.com.au
Ph: 1300 308 525
www.sustainabilityhouse.com.au
research@sustainabilityhouse.com.au
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Contents
EXECUTIVE SUMMARY ....................................................................................................................................... 3
INTRODUCTION ................................................................................................................................................. 4
METHODOLOGY ................................................................................................................................................. 5
Electronic Survey Analysis ............................................................................................................................. 6
RESULTS ............................................................................................................................................................. 6
Electronic Survey ........................................................................................................................................... 6
Face-to-face Interviews ................................................................................................................................. 7
Star Rating Graphic ........................................................................................................................................ 7
NatHERS Universal Certificate ..................................................................................................................... 11
Scalable Design Feature............................................................................................................................... 16
Construction Details Block and Stamp ........................................................................................................ 18
Training / Information ................................................................................................................................. 22
Other Comments ......................................................................................................................................... 22
CONCLUSION ................................................................................................................................................... 23
APPENDICES..................................................................................................................................................... 25
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EXECUTIVE SUMMARY
The Department of Climate Change and Energy Efficiency (DCCEE) commissioned Sustainability
House to undertake market research to guide design and content for a Nationwide House Energy
Rating Scheme (NatHERS) universal certificate, funded by all Australian jurisdictions represented
through the National Framework for Energy Efficiency (NFEE). Development of a universal
certificate is intended to unify the residential building energy rating certificate generated by each of
the three approved NatHERS software programs.
DCCEE supplied Sustainability House with a number of proposed designs for market research
which included:
Two example universal certificate designs;
A series of rating graphics that visually summarise the energy efficiency rating;
Two example construction details blocks which provide an abridged version of the
certificate; and
Two scalable design features which incorporate the rating graphic and information
about the rating, with the potential to use in a number of different ways including as a
sticker on or in meter boxes.
Market research primarily sought feedback from stakeholders using an online survey,
which received more than twice as many responses as anticipated from a broader range of
stakeholders and locations. The 76 survey respondents represented home buyers, council,
building surveyors, energy assessors and designers/builders. Face-to-face and phone interviews
were used to seek further clarification from a number of survey participants.
Feedback about the rating graphic indicated that two-thirds preferred a decimal number to
represent the star rating rather than a whole number, and three-quarters preferred it presented as
a number only rather than a number out of 10. Most survey respondents also preferred the rating
graphic to display predicted annual energy consumption (67%), the government website (67%) and
the scheme name (88%). Almost one-third of respondents suggested adding further information to
the rating graphic such as disclaimers, relevance to carbon emissions or financial savings, site
details or assessor details.
Response to the universal certificate overall indicated that most respondents found all the
information they required on the example certificates. 30% suggested additional information and
18% offered suggestions to make certain details more prominent. Suggestions for further
information fell into the categories of upgrades/improvements, inclusion of the certificate in the
building specification or plans, construction or site details, changes to the format and information
on the rating or its assumptions.
Most survey respondents agreed that the proposed scalable design feature contained sufficient
information. Opinions on whether to apply the scalable design feature as a sticker to meter boxes
were more mixed, varying by respondent group. Overall more than half of the sample agreed or
strongly agreed with this idea; agreement was highest among home buyers.
In addition to the questions on the certificate designs, the opportunity was taken to add questions
on training in relevant energy efficiency topics and the NatHERS scheme in particular. While just
over half of the respondents said they personally had sufficient training, generally the training was
not readily available and that they had to identify and seek the training themselves. The responses
included requests for both web-based and classroom-style training. It was also suggested that
training for a broader range of stakeholders, in addition to energy assessors, be investigated
further.
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INTRODUCTION
Sustainability House was commissioned by DCCEE in February 2013 to undertake market
research to guide design and content for a Nationwide House Energy Rating Scheme (NatHERS)
universal certificate; a residential building energy rating certificate for new houses and extensions
to be used throughout Australia. This research was funded by all Australian jurisdictions
represented through the National Framework for Energy Efficiency (NFEE).
Currently there are three NatHERS approved rating software tools, AccuRate, FirstRate5 and
BERSpro. Each programme produces a star rating between 0 and 10 stars, where 6 star rating is
the minimum energy efficiency required to comply with the National Construction Code in most
states and territories. While the number of stars is the same in each programme, the certificates
produced and the amount of supporting information presented is different. This difference in the
certificate design and the supporting information can be confusing to stakeholders who are not
trained energy assessors, such as council officers, homeowners, building surveyors and builders.
Development of a universal certificate is intended to:
Improve consistency in presentation of energy rating certificates;
Detail all key information included in a residential building energy rating; and
Be clear and easy to understand by key certificate users including home owners, council
staff and certifying personnel (building surveyors).
Prior to commencement of this study a graphic designer was engaged by DCCEE to develop a
series of example designs for the proposed NatHERS Universal Certificate as well as the following
certificate elements:
Rating graphic - to be included at the beginning of a certificate which clearly displays the
energy efficiency rating of a dwelling;
Construction details block - an abridged version of the certificate which could be used on
house plans; and
Scalable design feature - incorporates the rating graphic and information about the rating,
with the potential to use in a number of different ways including as a sticker on or in meter
boxes.
Examples of proposed certificate designs and certificate elements, as developed by the graphic
designer in consultation with DCCEE, are included in the Results and Appendix 1a-c.
This study sought to gauge the response of key users of the NatHERS rating certificates to the
proposed design and content for the NatHERS Universal Certificate, and to obtain feedback to
guide final development.
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METHODOLOGY
Market research was conducted by the Sustainability House research team between February and
March 2013. This research primarily used an electronic survey technique, supplemented by face-
to-face and phone interviews, as detailed below.
This study was initially intended to ascertain the responses of 30 people from key certificate user
groups; five homeowners, five council staff and five building surveyors in both Adelaide and Perth
(as representative of Australian capital cities). However, the study’s scope was broadened early in
the research period to include building designers, builders and energy assessors. This step also
widened the geographic spread of respondents, so that most states of Australia were represented
in the final sample (WA, SA, Vic, NSW, NT).
Potential survey participants were contacted via several avenues:
Phone calls to council offices and registered building certifiers;
Phone calls and emails to new homeowners who had engaged Sustainability House to
undertake energy ratings on their new homes or extensions in the past 12 months, or who
were known to Sustainability House staff;
Email to Australian Institute of Building Surveyors (AIBS) and Planning Institute of Australia
(PIA) members; and
Email to Building Designers Association of Victoria (BDAV) and Association of Building
Sustainability Assessors (ABSA) members.
Participants were invited to complete an online survey and asked for their consent to follow-up
contact by phone or in person. Participation was entirely voluntary: participants were not paid,
reimbursed or offered gifts in return for their participation, nor was it required of them by either their
employers or professional associations.
The online survey contained 30 questions, many of which were structured in a multiple choice
format. Many of the questions also contained an open-ended comments field offering participants
the opportunity to add their observations and suggestions.
The survey questions were developed in consultation with DCCEE project managers Paul Nagel
and Angie Marlow and market research sub-contractor Helen Skippen from Corporate Context, and
in accordance with the following principles:
Address the purpose of the research;
Be clear and succinct;
Proceed in a logical sequence without unnecessary repetition;
Address a single point per question; and
Be appropriate to both technical and non-technical target audiences.
The complete final survey, as hosted on www.freeonlinesurveys.com, is provided in Appendix 2.
One participant from each of the respondent groups in each location was contacted for a follow-up
interview to validate the survey responses. Interview questions were developed based on a
combination of feedback from all survey participants, and were designed to shed further light on
issues raised by respondents in the electronic survey.
Follow-up face-to-face interviews were arranged with participants, usually at their workplace or a
convenient meeting place, and took 45-60 minutes each. Participants were identified for follow-up
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on the basis of their having offered comments in the electronic survey and their willingness and
availability to participate in the interview.
Follow-up interviews consisted of questions seeking more detailed responses on the certificate
design and each of its elements, the NatHERS scheme and how the certificate is used in
respondents’ workplaces.
Electronic Survey Analysis
Quantitative data was statistically analysed for trends. Responses to the open-ended questions
were compiled manually, coded into categories according to their subject matter and analysed
across all respondents as well as by subgroup. Due to the small sample size for subgroups, results
have not been tested for statistical significance, but examples are provided to illustrate the
identified themes.
A summary of results was prepared with responses to the proposed star rating graphic, certificate,
scalable design feature, construction details block/stamp and finally comments relating to training,
information and any other comments. Each section first presents results from the sample as a
whole, then by respondent group. While results were partially explored by location, these results
are not presented herein as they were not considered to provide further insights due to the small
sample size.
RESULTS
Electronic Survey
A total of 76 responses to the electronic survey were received. This included 29 from Adelaide, 24
from Perth and 23 from other locations in Australia including other capitals and regional centres
that incorporated New South Wales, Victoria, Western Australia, South Australia and the Northern
Territory. A summary of survey participants by group and location is provided in Table 1. A
summary of responses to multiple choice questions is provided in Tables 2-6, while short answer
responses are summarised by question in Appendix 3.
Nearly one-third of respondents identified themselves with more than one rating certificate user
group. Most commonly this took the form of building surveyors who were also employed by council
(8 out of 19 building surveyors), and energy assessors who were also building designers (9 out of
38 energy assessors).
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Table 1. Number of survey respondents in each group by location.
NO. OF Building Council Home Energy Designer/
RESPONDENTS surveyor staff buyer assessor builder
Adelaide 8 10 7 7 0
Perth 9 6 5 9 6
Other 2 1 2 21 7
TOTAL 19 17 14 38 13
Please note that some respondents are included in more than one certificate user group above. In
the overall responses below, each respondent is counted only once.
Face-to-face Interviews
Three participants each from Perth and Adelaide were interviewed in person following the
electronic survey. Their responses provided in-depth insights to complement the survey data, and
are incorporated where relevant in the results below.
Star Rating Graphic
Overall results
A summary of respondent preferences about design and content for the star rating graphic are
presented in Table 2, while overall star rating graphic preferences are presented in Figure 1.
Analysis of preferences in display of the star rating number revealed that two-thirds of respondents
preferred a decimal number rather than whole number, and three-quarters preferred it presented
as a number only rather than a number out of 10. In terms of the design of the star rating graphic,
Examples 5-6 (Star archway 3 - out of ten) gained over half the vote, followed by the other star
archway examples. Only 2.6% (n = 2) of respondents preferred the horizontal bar display option.
Overall 32% of respondents preferred Example 5b, followed by 6b (12%). 60% of the sample found
their preferred graphic easy to understand and 56% wanted no further information added to it.
Two-thirds of respondents agreed that it is important to display the predicted annual energy
consumption on the rating graphic and wanted to see the government website address on the
graphic. Over 87% of respondents wished to see the name of the scheme included in the graphic
and most of these preferred the full name “Nationwide House Energy Rating Scheme” as in
Examples 3-4.
Of the 30% of respondents who suggested adding further information, their suggestions fell into
the categories of explanatory information or disclaimers (e.g. explaining what the rating is based
on, its limitations, or how it relates to carbon emissions or financial savings), rating results (heating,
cooling and total energy loads), site details (e.g. address and climate zone) or information to
identify the assessor and/or the NatHERS scheme and to facilitate follow-up.
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Figure 1. Most popular star rating graphic designs: 5a and 5b.
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30
25
Number of Respondents
20
15
10
5
0
1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b
Preferred Star Rating Graphic
Figure 2. Overall preference for proposed star rating graphics by number of respondents.
Building surveyors
Of the building surveyors, most preferred examples 5-6, with 5b the clear favourite. They found the
graphic easy to understand and most wouldn't add anything, although a few suggested adding
heating and cooling load, climate zone or assumptions of the rating. In a face-to-face interview,
one building surveyor said that including heating and cooling loads on the graphic was ‘critical’.
Council staff
Council staff had a slight preference for a decimal number and a number out of 10 on the rating
graphic. Most preferred examples 5-6 (5b and 6b). Some suggested explanatory information for
consumers such as comparing their rating with a State average or converting it to carbon emission
figures.
Home buyers
Home buyers uniquely preferred to see the star rating as a whole number only. However, like the
other groups, they too wanted to see annual predicted energy consumption, the government
website address, and to have the full name of Nationwide House Energy Rating Scheme included.
When queried about preferences for individual rating graphic elements most initially indicated a
preference for examples 5-6, though typically selected examples 1a or 5a when requested to
select a single preferred graphic from the proposed designs. One interviewed home buyer pointed
out that that the star archway graphics are easy to understand due to their similarity to appliance
rating graphics, but found the use of colours confusing for graphics 1a-2b due to the use of red for
better performance. Only one home buyer sought more information on the rating graphic; heating
and cooling loads.
Energy assessors
Most energy assessors preferred a decimal number and not out of 10 for the rating graphic. Half
the energy assessors preferred Example 5b, while most others preferred 3b or 6b. Nearly all
respondents said their preferred graphic was easy to understand, but half wanted to add features,
e.g. assessor's name and or number, conditioned area, heating and cooling loads (some disagreed
strongly with inclusion of the predicted energy use), disclaimers and climate zone.
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Table 2. Respondent preferences about design and content for the proposed star rating graphic (n
= number of respondents, % = percentage of respondents).
n %
Star rating displayed as a whole or decimal number
Whole 25 32.9
Decimal 50 65.8
Undecided 1 1.3
Star rating displayed as just a number or a number out of ten
Number only 58 76.3
Number out of ten 18 23.7
Preferred star rating graphic display
Star archway 1 - segmented (Examples 1-2) 15 19.7
Star archway 2 - plain (Examples 3-4) 13 17.1
Star archway 3 - out of ten (Examples 5-6) 44 57.9
Horizontal bar (Examples 7-8) 2 2.6
Undecided 2 2.6
Display of predicted annual energy consumption figures
Display 51 67.1
Don't display 18 23.7
Undecided 7 9.2
Display of scheme name
Don't display 5 6.6
Yes - "Nationwide House Energy Rating Scheme" 44 57.9
Yes - "NatHERS rating" 23 30.3
Undecided 4 5.3
Display website on rating graphic
Display 51 67.1
Don't display 18 23.7
Undecided 7 9.2
Preferred graphic easy to understand
Strongly disagree 4 5.3
Disagree 1 1.3
Undecided 4 5.3
Agree 50 65.8
Strongly agree 17 22.4
Any other info for graphic
No 44 57.9
Undecided 10 13.2
Yes 22 28.9
Designers/builders
Designers/builders favoured the star rating to be displayed as a decimal number, not out of 10, and
preferred graphic examples 5-6. Most recommended display of predicted annual energy
consumption, though one builder argued strongly against this, stating that it “is not the purpose of
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the rating”. Designers/builders were evenly split on whether to include the website on the star
rating graphic. Their preferences for an example graphic varied widely, with only three votes for the
most popular; Example 5b. Many wanted more information on the graphic but there was little
agreement on what should be included within this group. Two respondents wanted the assessor
accrediting organisation to be included.
NatHERS Universal Certificate
Overall results
Respondent preferences for design and content for the proposed NatHERS Universal Certificate
are summarised in Tables 3 and 4, which shows answers for multiple choice questions. While just
over half of respondents preferred the overall design of Example 1, a slim majority preferred
Example 2 for border design, report heading design, the three data boxes and the text box design.
Star rating, dwelling address and predicted annual energy use were considered the three most
important pieces of information sought from the certificate, followed by assessor accreditation
details.
Over 70% of respondents found all the information they required on the example certificate. 30%
suggested additional information and 19% offered suggestions to make certain details more
prominent. Their suggestions fell into the categories of upgrades/improvements, inclusion of the
certificate in the building specification or plans, construction or site details, changes to the format
and information on the rating or its assumptions.
Table 3. Respondent preferences about design for the proposed NatHERS Universal Certificate (n
= number of respondents, % = percentage of respondents).
n % n % n %
Certificate preference for the following elements Example 1 Example 2 Undecided
Overall design 39 53.4 30 41.1 4 5.5
Border along top of page 23 31.5 44 60.3 6 8.2
Report heading design 31 42.5 35 48 7 9.6
Three data boxes 26 35.6 40 54.8 7 9.6
Text box design 29 39.7 39 53.4 5 6.9
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Figure 3a. Certificate Example 1 (first page)
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Figure 3b. Certificate Example 2 (first page)
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Table 4. Respondent preferences about design and content for the proposed NatHERS Universal
Certificate (n = number of respondents, % = percentage of respondents).
n %
Three most important things in NatHERS certificate:
Star rating 68 89.4
Energy use 29 38.2
Floor area 10 13.2
Software 11 14.5
Assessor contact 7 9.2
Assessor accreditation 25 32.9
Dwelling address 34 44.7
Orientation 4 5.3
Plan reference number 6 7.9
Summary of construction types/ specifications 17 22.4
Comprehensive construction types/ specifications 8 10.5
Lighting 5 6.6
Software modelling details/ assumptions 5 6.6
Other 6 7.9
Example certificates contain all required information
Strongly disagree 3 4.1
Disagree 7 9.6
Undecided 7 9.6
Agree 53 72.6
Strongly agree 3 4.1
Other required information on certificate
No 41 56.2
Undecided 10 13.7
Yes 22 30.1
Information displayed differently/ more prominently on certificate
No 44 60.3
Undecided 16 20.5
Yes 14 19.2
Building surveyors
Building surveyors preferred Example 1 of the certificate for all features, except the border design
where Example 2 was preferred. They looked for star rating, assessor accreditation details,
dwelling address, software details and construction specs. Less than one quarter requested for
more information to be included, but their focus was on more detailed construction info, especially
windows, and the ability to check that the specified insulation could be fitted in the wall thickness.
One interviewed surveyor was concerned about duplicate information and different specifications,
pointing out that the certificate and stamped plans must match. Interviewed building surveyors
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both emphasised the importance that the certificate include as much detail as possible, explaining
“the more information the better”.
Council staff
Council staff generally preferred Example 1 of the certificate front page, particularly for overall
design and layout. They looked for star rating, dwelling address, predicted energy use,
construction specs and assessor accreditation. Most found all the information they needed in the
certificate examples, but a few highlighted a need for predicted energy use, window schedules,
and for the certificate and building specification to work seamlessly together for certification and
estimation purposes.
Home buyers
Home buyers preferred Example 2 for all the features in question. They looked for star rating,
dwelling address, predicted energy use, construction specs and floor area. Home buyers generally
found all the information they needed on the certificate, but a couple asked for the home owner's
name and address, and for client and home owner to be differentiated. They suggested that
energy loads and climate zone could be displayed more prominently. One of the interviewed home
buyers suggested display of the dwelling address more clearly, possibly as a heading underneath
the rating graphic. Another interviewed home buyer thought that home buyers aren’t interested in
the “nitty gritty” details provided in the certificate and suggested they would only like to see a
summary report with website where they could find more detail if they wished.
Energy assessors
Energy assessors preferred Example 2 of the certificate for all features and looked for star rating,
dwelling address, assessor accreditation, predicted energy use and construction specs. Many
wished to see more information that displayed inputs (i.e. a features page) and some
acknowledged that this may be possible in following pages, particularly to have space to allow for
multiple construction types. “DP number” was identified as being needed for NSW. Other
suggestions for additional information to be displayed on the certificate included detailed window
schedule for each window (including U-value, Solar Heat Gain Co-efficient, orientation and
shading), window-to-floor-area ratio, separate postcode field to ensure that this is included,
allowance for multiple construction types (e.g. brick veneer and fibre cement sheet external walls
or for new and existing constructions for renovations), assessor signature, site exposure and both
NatHERS and BCA climate zones. There was no consensus among assessors on which of the
many features should be displayed more prominently. Some respondents commented on how to
make the certificate user-friendly, e.g. requiring one certificate for multi-unit developments;
ensuring that the software completes the certificate automatically (no manual data entry); and
keeping it simple to ensure it will be more readily approved.
Designers and builders
Designers and builders preferred Example 1 for overall design, border and heading but Example 2
for data boxes and text boxes. Their priorities when looking at certificates were the star rating,
assessor accreditation, dwelling address, plan reference numbers and construction specs.
Designer/builders asked for more scope to include additional detail, especially glazing, and one
respondent emphasised that "thermal performance loads" would be more appropriate wording than
“predicted energy use".
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Scalable Design Feature
Overall results
Respondent preferences about the proposed scalable design feature multiple choice questions are
provided in Table 5. Two-thirds of respondents preferred Example 1 (Figure 2a) of the scalable
design feature and 74% thought it didn’t need anything added. Opinions on whether to apply it as a
sticker to meter boxes were more mixed, varying by respondent group as outlined below. More
than half of overall survey sample agreed or strongly agreed with this idea, while agreement was
highest among home buyers.
Table 5. Respondent preferences about design and content for the scalable design feature (n =
number of respondents, % = percentage of respondents).
n %
Proposed scalable design feature preference
Example 1 48 66.6
Example 2 21 29.2
Undecided 3 4.2
Suggestions under "about this energy rating"
No 47 64.4
Yes 26 35.6
Other information to be included in scalable design feature
No 54 74
Yes 19 26
Beneficial to display energy rating sticker on meter box
Strongly disagree 11 14.3
Disagree 10 13
Undecided 16 20.8
Agree 27 35.1
Strongly agree 13 16.9
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Figure 4a: Scalable Design Feature Example 1
Figure 4b: Scalable Design Feature Example 2
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Building surveyors
Building surveyors overwhelmingly preferred the scalable design feature Example 1. They
suggested that the section "about this energy rating" should include assumptions and limitations of
the rating, particularly a note concerning the impact of potential future alterations upon the rating.
The majority agreed with the concept of a sticker on the meter box, but a few raised concerns
about it being invalidated quickly by alterations, being easily removed, not necessarily reflecting
the actual performance of the building, or thought that the information could be simply provided at
time of sale.
Council staff
Two-thirds of council staff preferred Example 1 of the scalable design feature. Comments included
suggesting disclaimers relating to predicted energy use, assumptions about occupant behaviour
and future alterations invalidating the rating. Most council staff agreed with the use of the scalable
design feature as a sticker on meter boxes. In a face-to-face interview, one council staff member
pointed out that displaying the predicted energy use here could be helpful, as it would clarify the
underlying assumptions of the star rating.
Home buyers
Eight home buyers preferred Example 1 while 5 preferred Example 2 of the scalable design
feature. Aesthetically some found Example 2 more pleasing, while preferring the star rating graphic
on Example 1. Several homebuyers suggested adding disclaimers under “About this energy
rating", outlining the limitations of the rating. None objected to stickers on meter boxes but one
commented that builders might not apply such stickers if the design had changed since the rating.
One interviewed home buyer was concerned about the longevity of a sticker and preferred to
access this information on a website.
Energy assessors
The majority of assessors preferred Example 1 of the scalable design feature, while many also
suggested that a disclaimer should be added about the assumptions of the rating. Many of their
other suggestions related to transparency and accountability, e.g. assessor
name/number/accrediting organisation; NatHERS website and details of software used. Energy
assessors expressed a stronger level of disagreement (44%) with the proposal for meter box
stickers than did other respondent groups. Their concerns mostly related to future changes that
could invalidate the rating. One assessor’s concern about client acceptance of stickers would seem
to be negated by the overwhelming support for the concept as expressed by home buyers.
Designers/builders
Designers/builders similarly preferred Example 1 of the scalable design feature. Suggestions
included adding disclaimers on the rating, adding the software version details, builder's contact
details for accountability and construction details.
Construction Details Block and Stamp
Overall results
A summary of responses to multiple choice questions about the proposed construction details
block and electronic stamp are provided in Table 6. Results found that 49% of the overall sample
preferred Example 1 of the construction details block (Figure 3a); 41% preferred Example 2 (Figure
3b) and 10% were undecided. Of the one-fifth of respondents who added comments, most wanted
to include more detail, particularly on glazing and other construction, or to have greater provision
for complex buildings with multiple construction types.
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Table 6. Respondent preferences about design and content for the construction details block and
electronic stamp (n = number of respondents, % = percentage of respondents).
n %
Preference for proposed design layout of construction details block
Example 1 36 49.3
Example 2 30 41.1
Undecided 7 9.6
Other information to be included in construction details block
No 47 64.4
Undecided 12 16.4
Yes 14 19.2
Other information to be included in electronic stamp
No 51 69.9
Undecided 6 8.2
Yes 16 21.9
Building surveyors
Most building surveyors preferred Example 1 of the construction details block and didn't require
any more info to be included, although 5 were undecided about this and requests for more
information included a full window schedule and prompts (presumably meaning example text) to
help fill in the details correctly. A few suggestions for the proposed stamp included adding the star
rating, air infiltration measures, version number, and not stamping plans at all "as plans are often
superseded".
Council staff
Council staff generally preferred Example 1 of the construction details block, and didn't require any
further information to be included, but some suggested more info including window schedule and
prompts to complete the fields correctly. Most had no suggestions for altering the proposed stamp.
Home buyers
Five home buyers preferred Example 1 while 7 preferred Example 2 of the construction details
block. Only two asked for more information - address of premises and heating, cooling and total
energy loads.
Energy assessors and designers/builders
Energy assessors and designers/builders were also divided over which design was preferable for
the construction details block, with slightly more energy assessors preferring Example 2 and
designers/builders preferring Example 1, and many suggestions, e.g. provision for complex
designs with extra options that can be activated by ticking a box, and space for more
comprehensive construction details.
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Figure 5a: Construction Block Example 1
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Figure 5b: Construction Block Example 2
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Training / Information
Overall results
Final survey questions about information and training received relating to NatHERS were optional.
Of the 44 responses to whether sufficient information or training about energy efficiency and the
NatHERS scheme had been received, 25 respondents said yes, 3 said no and the remainder gave
more complex answers as outlined below by respondent group. Many highlighted particular areas
for further training, and there were requests for both web-based and classroom-style training.
Given the number of issues raised, the high rate of ‘yes’ responses may reflect a degree of
pressure to maintain a competent professional image in spite of needs for additional training.
Building surveyors
Building surveyors had mixed responses regarding training and information, highlighting the need
to keep up with new software, dealing with building applications which use a combination of DTS
and software assessment, and the need for assessors to fully understand construction issues in
order to specify realistic upgrades. They suggested that electronic training would be convenient as
it can be replayed as needed.
Council staff
Council staff responses on training were also mixed, with some indicating they felt they had
sufficient training while others questioned whether anyone really understood the complexities of
energy assessment and highlighted a need for ongoing training in both software assessment and
BCA regulations. One respondent commented that building surveyors tend to see compliance as
the assessor's problem, and don't see it as their role to ensure that construction complies with the
assessment.
Home buyers
Three home buyers indicated that insufficient information on energy assessment or thermal
performance of designs was provided (e.g. by builders' sales staff) and that they would like more
information to be available. Home owners also commented that they would like to receive
information or training on how to use less energy in their house.
Energy assessors and designers/builders
While many energy assessors and designers/builders responded that they personally had
adequate training and information, some stated that this was through their own efforts to seek it out
or through company policy, and that extensive training was not readily available to sole traders or
required by the industry. Some would like to see more online training available and/or centralised
online information updates relating to energy assessment protocols to help ensure consistency
across the industry.
Other Comments
Overall results
A few compliments on the initiative to develop a universal certificate were saved for this section.
There were no suggestions that the existing certificate formats should be maintained. Comments
fell into the categories of training, accreditation or auditing (e.g. assessor training for certifiers,
auditing of assessors); “real world” issues (e.g. generating paperwork that may not necessarily be
read and followed); user-friendliness of the certificate (e.g. automating data entry; obtaining
feedback from auditors); and scope for greater detail (e.g. energy loads by zone; multiple
construction types; multi-unit developments).
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Building surveyors and council staff
Five building surveyors offered further comments. One suggested that all building surveyors
needed to be qualified energy assessors. Another building surveyor who also works for a council
suggested "get on with it... great to see we are moving a little again", while another queried
whether the system delivers housing stock that actually performs as rated. An inteviewed building
surveyor suggested that the energy rating take consider peak load use.
Home buyers
Only one home buyer commented, though they endorsed the proposals to have a consistent
certificate and to use stickers in meter boxes as “great ideas”. In interview, one home buyer
expressed doubt that the information on the report would ensure the building was constructed as it
ought to be. One home buyer also highlighted the fact that they had not received their energy
rating certificate from the builder, though they had been informed what star rating their home
achieved.
Energy assessors and designers/builders
Several energy assessors and designers/builders applauded the initiative to develop a universal
certificate and were keen to see it implemented. Many reiterated earlier comments, e.g. provision
for multiple construction types, user-friendliness of the certificate both for the assessor (data
automatically generated from software) and the certifier (easy to follow and not too lengthy). Some
repeated issues about accountability, such as being able to identify assessors and determine
whether they were accredited.
CONCLUSION
Market research sought feedback from a sample size more than 2.5 times larger – and from a
broader geographical range and demographic – than the study originally aimed to sample. This
allowed for a more comprehensive appraisal of industry preferences and perceptions of the
proposed universal certificate and elements. The survey participants included the core study
groups (building surveyors, council and new home buyers), as well as builders/designers and
energy assessors. These latter groups typically provided comprehensive feedback and in this
sense were valuable additions to the sampled study groups.
Survey respondents broadly offered support for the development of a NatHERS universal
certificate and the proposed designs were well-received by certificate user groups. Based on
respondent feedback, an area that is likely to cause the greatest controversy is the inclusion of
predicted annual energy consumption figures on the universal certificate. While some stakeholders
strongly support the need to include this information, others strongly disagreed citing that the
energy rating is only a prediction. Similarly responses to the use of the scalable design feature as a
sticker were mixed, with some respondents questioning the validity of an energy rating beyond
date of installation as post-occupancy changes are made which impact energy performance.
These concerns could be alleviated with a disclaimer about the annual energy consumption
serving as a prediction only and description of modelling assumptions. The introduction of an
energy labelling system could be most effective in combination with a program of energy disclosure
for existing houses.
The inclusion of predicted energy consumption data has the potential to provide many benefits.
One of these is that it could serve as a benchmark in energy performance standard for home
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owners to achieve, drawing attention to energy use and encouraging home owners to question
why they aren’t achieving predicted energy consumption standards. This may increase market pull
from home owners for more energy efficient dwellings beyond regulatory performance standards,
demand for higher quality builds or encourage some home owners to adopt more energy efficient
practices. Some home owners thought education would be a better method of improving energy
use than energy labelling. Our experience in providing education to home owners indicates they
are quite receptive to energy efficiency information, particularly to the possible impacts of quality of
building on thermal performance and comfort.
Most survey respondents liked the proposed design and content for the certificate and certificate
elements, and suggested changes were generally minor. However, some respondents, particularly
energy assessors, raised concerns about whether the proposed universal certificate layout allowed
for multiple construction types, and the need for other information to be included such as a detailed
glazing schedule with details for each window by zone, window-to-floor-area ratio and site
exposure. Some respondents also wished to see extensive details provided in the construction
details block, to be used as a stamp on plans. This raises the question of how effectively such a
detailed document could be scaled down to fit on plans without obscuring too much of the
background detail and without losing legibility. Some suggested that plans should not be stamped
at all, since they are frequently subject to change after assessment (even though the assessment
is supposed to refer to the final design).
It may be worth considering some of the following options to address the need for (a)
comprehensive details to be available to assessors and certifiers, and (b) summary information to
be presented on plans to verify that they have been assessed correctly:
1. For the purpose of stamping plans, use a modified version of the star rating graphic,
including assessor number, certification number and date as well as the details listed
under “plan documents” on the certificate for cross-reference with the correct version of
plans and the full certificate.
2. Allow for the “construction details” page of the certificate to expand onto additional pages
as required to accommodate multiple construction types. Number these construction types
(e.g. external wall type 1, external wall type 2, etc) so that the full details of each
construction (e.g. rendered brick veneer with 40mm air gap, R2.0 glasswool and 10mm
plasterboard) can be identified. For simple designs all the construction details could still fit
on a single page.
3. Address minor corrections required to the certificate as noted in Appendix 4.
4. Adapt the construction details block (minus assessment details) for builders/ designers to
complete and provide along with their plans to assessors, in order to improve consistency
and efficiency of assessment inputs. Information provided on this form could take
precedence over notes included on plans and could facilitate more streamlined auditing of
assessments.
Further recommendations include:
Trialling the certificate for a range of dwellings with different construction types (e.g.
renovation with new and existing construction elements, multi-unit development) to see
how this impacts certificate layout;
Providing a full window schedule as supplementary information;
A graphic representation of the heating and cooling loads separately from the overall star
rating;
Explore options to facilitate better access to energy rating certificates for home owners,
such as an online database, further information through council, regulating builders to
provide certificates or integrating this into an existing building disclosure scheme;
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Include a summary of energy efficient practices for home owners with the summary energy
rating report, including website details for access to more detailed information.
In taking the next steps towards the introduction of a NatHERS universal certificate there are a
number of factors to consider, particularly in developing the software to automatically produce the
report. One of these is that some data contained in the proposed universal certificate is not
currently contained in NatHERS software, such as building class. Similarly there is a lot of
information in the front-end of the NatHERS softwares that would need to be written into the
Chenath engine. Consequently some information would either need to be completed manually or
the software developed to incorporate this information. An independant service could be
implemented that examples the files separely from the rating software.
The central collection of all assessment would enable a raft of improvements to the current
scheme, including quality control and policy development . Collecting building plans at this stage
would remove one of the biggest hurdles to the improvement of existing buildings: the need to
create plans where they no longer exist.
In summary, there is much support in the industry for the development of a NatHERS universal
certicate and this provides an important step towards improving residential energy ratings in
Australia.
APPENDICES
Appendix 1a-c: Example universal certificate and certificate element designs
Appendix 2: Survey questions
Appendix 3: Electronic Survey – Text Responses
Appendix 4: Minor corrections to certificate
Appendix 5: Certificate element preferences
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research@sustainabilityhouse.com.auAPPENDIX 1a: EXAMPLE RATING GRAPHICS
1a 1b 2a 2b
BUILDING RATING BUILDING RATING BUILDING RATING
1 1.2 1 10 1.2 10
Energy consumption Energy consumption Energy consumption Energy consumption
1234 1234 1234 1234
BUILDING RATING BUILDING RATING BUILDING RATING BUILDING RATING
6 6.5 6 10 6.5 10
Energy consumption Energy consumption Energy consumption
1234 1234 1234 1234
3a 3b 4a 4b
1 1.2
1 1.2 10 10
6 6.5
6 6.5 10 10
5a 5b 6a 6b
1
The more stars
1.2
The more stars
1 10
The more stars
1.2 10
The more stars
the more energy efficiant the more energy efficiant the more energy efficiant the more energy efficiant
Total Predicted Energy Consumption Total Predicted Energy Consumption Total Predicted Energy Consumption Total Predicted Energy Consumption
1234 1234 1234 1234
Mj/M per year
2
Mj/M per year
2
Mj/M2 per year
For more information on your dwelling’s thermal For more information on your dwelling’s thermal For more information on your dwelling’s thermal For more information on your dwelling’s thermal
shell rating see: shell rating see: shell rating see: shell rating see:
www.nathers.gov.au www.nathers.gov.au www.nathers.gov.au www.nathers.gov.au
6
The more stars
6.5
The more stars
6 10
The more stars
6.5 10
The more stars
the more energy efficiant the more energy efficiant the more energy efficiant the more energy efficiant
Total Predicted Energy Consumption Total Predicted Energy Consumption Total Predicted Energy Consumption
1234 1234 1234 1234
Mj/M per year
2
Mj/M2 per year
For more information on your dwelling’s thermal For more information on your dwelling’s thermal For more information on your dwelling’s thermal For more information on your dwelling’s thermal
shell rating see: shell rating see: shell rating see: shell rating see:
www.nathers.gov.au www.nathers.gov.au www.nathers.gov.au www.nathers.gov.au
7aBuilding Rating: 1
7b
Building Rating: 1.2
0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10
Building Rating: 6 Building Rating: 6.5
0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10
8a Building Rating: 1/10
8b
Building Rating: 1.2/10
0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10
Building Rating: 6/10 Building Rating: 6.5/10
0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10APPENDIX 1b: UNIVERSAL CERTIFICATE EXAMPLE 1
Nationwide House Energy Rating Scheme (NatHERS) Certificate
NEW DWELLING
Certification number Date of Certification
# # # # # # # # # # # # # # # #
1 OVERVIEW Star Rating: 6
6.5 | 10
Dwelling address:
Block no. Section no.
LGA Climate zone
BUILDING RATING
Assessor details
Name
Company name
Address
Phone/fax
Thermal performance loads (area adjusted)
Heating Cooling Total Garage
Email
Example text Example text Example text Example
text
Floor area (m²) (excluding garage) Accreditation no.
Conditioned Unconditioned Total
Example text Example text Example text Declaration of assessor interest
Class of building
e.g. Class 2 Client name
Key Construction and Insulation details (see over for more detail)
e.g. brick veneer with R1.5 wall insulation, R1.5 wall insulation,
sarking under roof tiles, low-e glazing...
More text... 2 PLAN DOCUMENTS
Downlights
File name Example text
Dwelling rated/not rated with downlights in living areas, kitchen
and main bedroom, see page 3 for details Date plans issued Example text
Nominal orientation of dwelling’s front door (from true north) Plan ID Example text
e.g. North-east Plans prepared by Example text
See Part 4: Explanatory notes for further information
1 of 4 NatHERS is an initiative of the Commonwealth, States and TerritoriesNationwide House Energy Rating Scheme (NatHERS) Certificate
NEW DWELLING
Certification number Date of Certification
# # # # # # # # # # # # # # # #
3 BUILDING FEATURES
CONSTRUCTION DETAILS
Windows Ceilings
Glass Type e.g. single Construction Example text
clear
Insulation Example text
Frame type e.g. timber
Details Example text
U-value^ e.g. North-
east
Roof
SHGC^ e.g. timber
Construction Example text
Total area Example text
Insulation Example text
Skylights/Roof windows Colour (solar Example text
absorbency)
Glass Type e.g. single clear
Details Example text
Frame type e.g. timber
U-value^ Example text
Fixed shading
SHGC^ Example text
Eaves (width Example text
Total area Example text including gutters)
Verandas, pergolas, Example text
external blinds
External Walls
(type, description)
Construction Example text
Insulation Example text Underfloor^
Colour (solar Example text Example text
absorbency)
Details Example text
Overshadowing^
Overshadowing Example text
Internal walls
Overshadowing heritage or Example text
Construction Example text protected trees
Insulation Example text
Details Example text
Floors
Construction Example text
Insulation Example text
Covering Example text
Details Example text
2 of 4 NatHERS is an initiative of the Commonwealth, States and TerritoriesNationwide House Energy Rating Scheme (NatHERS) Certificate
NEW DWELLING
Certification number Date of Certification
# # # # # # # # # # # # # # # #
3 BUILDING FEATURES
Nominal orientation of front door
e.g. North-east
ORIENTATION, EXPOSURE, VENTILATION AND INFLITRATION
Downlights Halogen CFL LED
Number 24 2 2
Type 240V 240V 12V
Covered (yes/no) No No Yes
Details if yes Example text Example text Example text
Wall vents, chimneys, exhaust fans, unflued gas appliances and other penetrations
Site exposure^ suburban
Roof space openness^ ventilated
Roof space openness^
^ see Part 4 – Explanatory notes for further information
Software name and version: Example text to go here
4 EXPLANATORY NOTES
Term Definition
NatHERS
Climate zone
L & S figures
Class of Building
u-value
SHGC
Colour (solar absorbency)
Overshadowing
Site exposure
Roof space openness
Underfloor
3 of 4 NatHERS is an initiative of the Commonwealth, States and TerritoriesNationwide House Energy Rating Scheme (NatHERS) Certificate
NEW DWELLING
Certification number Date of Certification
# # # # # # # # # # # # # # # #
4 EXPLANATORY NOTES
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DISCLAIMER
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CONTACT
For more information on the Nationwide House Energy
Rating Scheme (NatHERS), visit www.nathers.gov.au
For more information on energy efficient design and
insulation, visit www.yourhome.gov.au
4 of 4 NatHERS is an initiative of the Commonwealth, States and TerritoriesYou can also read
