Quality Statement
Main types of heating used measures the types of heating that are usually used to heat an occupied private dwelling. It indicates the appliances used, and, in most cases, the fuels used (for example, heat pump, fixed gas heater, wood burner). Excluded are any types of heating that are:
- only used very rarely
- available but not used
- disconnected or broken.
Insulation is not a heating type.
The main types of heating used data does not indicate how many heating appliances of each type were used in a dwelling. For example, it does not indicate the number of heat pumps used, or whether one electric heater or multiple electric heaters were used. Each type of heating reported was recorded once only.
Fuel types used to heat dwellings measures the main types of fuels used to heat an occupied private dwelling. Main fuel types used refers to those used most often, not every single type used in an occupied private dwelling. More than one main fuel type may be used such as electricity, gas, coal, and wood. Insulation is not a fuel type.
Main types of heating used: Moderate
Fuel types used to heat dwellings: Moderate
Data quality processes section below has more detail on the rating.
Priority level 3
A priority level is assigned to all census concepts: priority 1, 2, or 3 (with 1 being highest and 3 being the lowest priority).
Heating is a priority 3 concept. Priority level 3 concepts are given third priority in terms of quality, time, and resources across all phases of the census. Priority 3 concepts are those that are:
- data that census would not be solely run for, and information about population groups that could not be captured without being in a census
- data that is important to certain groups
- data that can be used to create sampling frames for other surveys.
The census priority level for heating remains the same as 2018.
The 2023 Census: Final content report has more information on priority ratings for census concepts.
Occupied private dwellings
‘Subject population’ means the people, families, households, or dwellings that the variable applies to.
Main types of heating used is classified into the following categories:
Census main types of heating used V2.0.0 – level 1 of 2
| Code | Category |
|---|---|
| 0 | No heating used |
| 1 | Heat pump |
| 2 | Electric heater |
| 3 | Fixed gas heater |
| 4 | Portable gas heater |
| 5 | Wood burner |
| 6 | Pellet fire |
| 7 | Coal burner |
| 8 | Other types of heating |
| 9 | Not elsewhere included |
The residual category ‘Not elsewhere included’ contains ‘Response unidentifiable’, ‘Response outside scope’, and ‘Not stated’. Follow the link above the table to examine the classification.
Main types of heating used is a multiple response variable so the number of responses will be greater than the number of dwellings.
In addition, the number of heating types used is classified into the following categories:
Census number of heating types used V2.0.0 – level 1 of 2
| Code | Category |
|---|---|
| 0 | No heating types used |
| 1 | One heating type used |
| 2 | Two heating types used |
| 3 | Three heating types used |
| 4 | Four heating types used |
| 5 | Five heating types used |
| 6 | Six heating types used |
| 7 | Seven heating types used |
| 8 | Eight or more heating types used |
| 9 | Not elsewhere included |
The residual category ‘Not elsewhere included’ contains the ‘Response unidentifiable’ and ‘Not stated’ categories. Follow the link above the table to examine the classification.
Fuel types used to heat dwellings is classified into the following categories:
Census fuel types used in dwellings V2.0.0 – level 1 of 2
| Code | Category |
|---|---|
| 011 | Electricity |
| 012 | Gas |
| 013 | Wood |
| 014 | Coal |
| 015 | Home heating oil |
| 016 | Solar power |
| 017 | No fuels used in this dwelling |
| 018 | Other fuel(s) |
| 999 | Not elsewhere included |
The residual category ‘Not elsewhere included’ contains ‘Response unidentifiable’, ‘Response outside scope’, and ‘Not stated’. Follow the link above the table to examine the classification.
Fuel types used to heat dwellings is a multiple response variable so the number of responses will be greater than the number of dwellings.
In addition, the number of heating fuels used is classified into the following categories:
Census number of heating fuels used V2.0.0 – level 1 of 2
| Code | Category |
|---|---|
| 0 | No heating fuels used |
| 1 | One fuel |
| 2 | Two fuels |
| 3 | Three fuels |
| 4 | Four fuels |
| 5 | Five fuels |
| 6 | Six fuels |
| 7 | Seven or more fuels |
| 9 | Not elsewhere included |
The residual category ‘Not elsewhere included’ contains ‘Response unidentifiable’ and ‘Not stated’. Follow the link above the table to examine the classification.
The 2023 Census classifications for main types of heating used and fuel types used to heat dwellings are both consistent with those used for the 2018 Census.
Standards and classifications has more information on what classifications are, how they are reviewed, where they are stored, and how to provide feedback on them.
Heating data is collected on the dwelling form (question 12 paper form).
There were differences in the way a person could respond between the modes of collection (online and paper forms).
On the online form:
- previous responses disappeared if ‘don’t use any form of heating’ was ticked
- the ‘other’ text field only became visible if ‘other’ was selected
- for the category ‘other’, an as-you-type auto-suggestion list appeared once the respondent started typing in the box. For example, if the respondent typed in wood, suggestions of ‘wood pellet fire’ and ‘wood burner’ appeared.
On the paper form:
- it was possible to give an inconsistent multiple response, for example, respondents could tick boxes indicating types of heating used and ‘don’t use any form of heating’. These responses were resolved by edits.
Data from the online forms may therefore be of higher overall quality than data from paper forms. However, processing checks and edits were in place to improve the quality of the paper form data.
Stats NZ Store House has samples for both the individual and dwelling paper forms.
Data-use outside Stats NZ:
- to identify areas affected by fuel poverty, and the populations who are most affected by this
- to understand changes in energy demands
- to track health outcomes and risk factors for respiratory and cardiovascular diseases
- for use by EECA (Energy Efficiency & Conservation Authority) to identify areas with low heat pump uptake to target for subsidies (for both heating and insulation)
- to track heating use against clear air heating legislation, monitor the effectiveness of energy and carbon-reduction policies, and inform air quality policies
- to support monitoring requirements of the National Environmental Standards for Air Quality and regional air quality plans
- for modelling particulate emissions and understanding how emission trends may be affected by changes in heating technology use
- to assist in dealing with fire incidents – it helps ensure firefighter safety (by identifying areas where many dwellings have gas heating) and targeting of responses to fires (by identifying areas with lots of firewood or easily combustible fuel available).
Data-use by Stats NZ:
- for in-depth reports such as Housing in Aotearoa: 2020
- to look at dwelling fuel use for an air emissions inventory.
The table below shows the distribution of data sources for both main types of heating used and fuel types used to heat dwellings. All data was from census forms as no alternative data sources were available.
| Data sources for heating data, as a percentage of occupied private dwellings, 2023 Census | |
|---|---|
| Source for heating data | Percent |
| 2023 Census response | 91.6 |
| Historical census | 0.0 |
| Admin data | 0.0 |
| Deterministic derivation | 0.0 |
| Statistical imputation | 0.0 |
| No information | 8.4 |
| Total | 100.0 |
| Note: Due to rounding, individual figures may not always sum to the stated total(s) or score contributions. | |
Editing, data sources, and imputation in the 2023 Census describes how data quality is improved by editing.
Missing and residual responses represent data gaps where respondents either did not provide answers (missing responses) or provided answers that were not valid (residual responses).
Percentage of ‘Not stated’ for occupied private dwellings:
Main types of heating used
- 2023: 8.4 percent
- 2018: 7.7 percent
Fuel types used to heat dwellings
- 2023: 8.4 percent
- 2018: 7.7 percent
- 2013: 5.1 percent
For output purposes, the residual category responses are grouped with ‘Not stated’ and are classified as ‘Not elsewhere included’.
Percentage of ‘Not elsewhere included’ for occupied private dwellings:
Main types of heating used
- 2023: 8.6 percent
- 2018: 8.8 percent
Fuel types used to heat dwellings
- 2023: 8.8 percent
- 2018: 9.3 percent
- 2013: 5.5 percent
Overall quality rating:
Main types of heating used: Moderate
Fuel types used to heat dwellings: Moderate
Data has been evaluated to assess whether it meets quality standards and is suitable for use.
Three quality metrics contribute to the overall quality rating:
- data sources and coverage
- consistency and coherence
- accuracy of responses.
The lowest rated metric determines the overall quality rating.
Data quality assurance in the 2023 Census provides more information on the quality rating scale.
Data sources and coverage
Main types of heating used: Moderate quality
Fuel types used to heat dwellings: Moderate quality
The quality of all the data sources that contribute to the output for the variable were assessed. To calculate the data sources and coverage quality score for a variable, each data source is rated and multiplied by the proportion it contributes to the total output.
The rating for a valid census response is defined as 1.00. Ratings for other sources are the best estimates available of their quality relative to a census response. Each source that contributes to the output for that variable is then multiplied by the proportion it contributes to the total output. The total score then determines the metric rating according to the following range:
- 0.98–1.00 = very high
- 0.95–<0.98 = high
- 0.90–<0.95 = moderate
- 0.75–<0.90 = poor
- <0.75 = very poor.
Data sources and coverage information for main types of heating used is derived from fuel types used to heat dwellings, and therefore the score is the same for both heating variables. The proportion of data from received forms contributed to the score of 0.92, determining the moderate quality rating.
| Data sources and coverage rating calculation for heating data, occupied private dwellings, 2023 Census | |||
|---|---|---|---|
| Source for heating data | Rating | Percent | Score contribution |
| 2023 Census response | 1.00 | 91.58 | 0.92 |
| No information | 0.00 | 8.42 | 0.00 |
| Total | 100.00 | 0.92 | |
| Note: Due to rounding, individual figures may not always sum to the stated total(s) or score contributions. | |||
Consistency and coherence:
Main types of heating used: High quality
Fuel types used to heat dwellings: High quality
Heating data is consistent with expectations across nearly all consistency checks for both the main types of heating used and the fuel types used to heat dwellings variables. There was some minor variation from expectations or benchmarks, which makes sense due to real-world change, incorporation of other sources of data, or a change in how the variable has been collected.
Heating data has been rated as high rather than very high because:
- there was a high proportion of missing information
- non-responding dwellings may have different patterns of heating use than responding dwellings.
In the 2018 Census, the metric 2 rating was high for types of heating used, while it was only moderate for fuel types used to heat dwellings. This increase in the rating for fuel types in 2023 Census is due to the data being highly consistent with expectations over time.
Accuracy of responses:
Main types of heating used: Very high quality
Fuel types used to heat dwellings: Very high quality
Heating data has no data quality issues that have an observable effect on the data. The quality of coding is very high. Any issues with the main types of heating used and fuel types used to heat dwellings appear in a very low number of cases (typically less than a hundred).
Heating data shows high levels of accuracy of responses collected both from paper and online, and bilingual and English forms.
Improvement in scanning repair for paper forms reduced the number of unidentifiable responses. This has led to an increase in the metric 3 rating from moderate in the 2018 Census to very high quality in the 2023 Census for both main types of heating used and fuel types used to heat dwellings.
Heating data for both main types of heating used, and fuel types used to heat dwellings can be used in a comparable manner to the 2018 Census.
Main types of heating used was introduced as a new form of heating information in the 2018 Census.
Time series analysis can be done for fuel types used to heat dwellings, but the 2018 and 2023 Censuses are not fully comparable with the previous data. This is due to the change in concept from ‘all types ever used’ to ‘main types used’ only and the increase in data in residual categories in the 2018 and 2023 data.
In addition, it is recommended that data users should be aware that:
- the amount of non-response was higher than in 2018, especially in areas affected by the severe weather events of 2023
- the higher proportion of missing data in certain areas may affect the representativeness of responses in these areas.
Comparisons to other data sources
Census is the only comprehensive source of information about heating data. Comparing 2023 Census data with other data sources should be done with care.
To assess how this concept aligns with the variables from the previous census, use the links below:
- Main types of heating used and fuel types used to heat dwellings - 2018 Information by variable
- Data about heating was not published in 2013.
Contact our Information centre for further information about using this concept.
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