Count of dwellings (information about this variable and its quality)

Priority level

Priority level 1

We assign a priority level to all census variables: Priority 1, 2, or 3 (with 1 being highest and 3 being the lowest priority).

The count of all dwellings is a priority 1 variable. Priority 1 variables are core census variables that have the highest priority in terms of quality, time, and resources across all phases of a census.

Overall quality rating for 2018 Census

High quality

The external data quality panel had provided an independent assessment of the quality of this variable and has rated it as high quality. 2018 Census External Data Quality Panel: Assessment of Variables has more information.

Subject population

All dwellings

‘Subject population’ means the people, families, households, or dwellings to whom the variable applies.

How this data is classified

The count of dwellings is a count of dwellings in the census dwelling frame. No classification is used for this count.

The overall dwelling count is broken down subnationally using geographic classifications. Statistical standard for geographic areas 2018 has more information.

The Standards and Classifications page provides background information on classifications and standards.

Question format

The census count of dwellings is taken from the census dwelling frame. Creating the census dwelling frame for the 2018 Census has more information.

Stats NZ Store House has samples for both the individual and dwelling paper forms.

2018 data sources

The 2018 Census dwelling frame was the only source of data for this variable. Creating the census dwelling frame for the 2018 Census has more information.

Missing and residual responses

As the count of dwellings comes from the 2018 Census dwelling frame, and not from a census form, there is no non-response.

Data quality processes

Overall quality rating: High quality

Data was evaluated to assess whether it meets quality standards and is suitable for use.

Three quality metrics contributed to the overall quality rating:

• data sources and coverage
• consistency and coherence
• data quality.

The lowest rated metric determines the overall quality rating.

Data quality assurance for 2018 Census provides more information on the quality rating scale.

Data sources and coverage: Very high quality

The only source of data was the 2018 Census dwelling frame. The count is based on the dwelling record type at meshblock level (the smallest statistical geography) of the dwelling frame. The dwelling frame provides very high coverage of dwellings in New Zealand.

Although the 2018 Census dwelling frame is very high quality, there was an undercount in the Marlborough region. The consistency and coherence section has more information.

Consistency and coherence: High quality

Dwelling counts data is consistent with expectations across nearly all consistency checks, with some minor variation from expectations or benchmarks that makes sense due to real-world change or a change in how the variable has been collected. Counts of private dwellings at regional council and territorial authority level of geography are consistent with expectations based on 2013 dwelling counts and building consents since 2013.

However, there are some quality issues to note:

• at lower levels of geography there are some areas with changes that are not consistent with time series
• for the 2018 Census, the dwelling counts include unoccupied non-private dwellings. These were not included in dwelling counts for previous censuses.
• changes to the census field methodology meant there was a less complete picture of secondary dwellings (eg a caravan or additional dwelling on a property) than in previous censuses due to less face-to-face contact with field staff
• the 2018 Census counted fewer dwellings in the Marlborough region than existed at census time. There was a significant undercount of unoccupied private dwellings in three Marlborough SA2 areas: Marlborough Sounds West, Marlborough Sounds East, and Marlborough Sounds Coastal Marine. This was due to an undercount in the dwelling list prior to field operations, field staff not finding many of these dwellings, and a lack of visibility of this under-coverage during the operational phase of the 2018 Census. These three SA2 areas had many relatively isolated dwellings without a standard street address. The identification of dwellings in these areas was affected by ex-tropical cyclone Gita, which hit New Zealand in February 2018, when field staff were checking addresses and delivering 2018 Census materials. Correction to Marlborough Dwelling Count has more information. If using Marlborough dwelling data, please contact census.external.relations@stats.govt.nz for more information.

Data quality: High quality

The dwelling frame is of very high quality. However, there were some quality issues relating to misclassified dwellings and undercounts of certain types of dwellings. The Dwelling type information by variable has more information.

Recommendations for use and further information

The overall quality of the count of dwellings data is high and comparable with 2006 and 2013 data. However, when using this data you should be aware that:

• caution is advised when using data for Marlborough as there was an estimated undercount of approximately 800 dwellings for the region. We recommend using Marlborough dwelling counts estimates found in the Correction to Marlborough Dwelling Count page, rather than the official 2018 Census counts. For more information on using Marlborough dwelling count data, please contact census.external.relations@stats.govt.nz.
• some caution is recommended when comparing dwelling counts over time due to the addition of unoccupied non-private dwellings in 2018.

Contact our Information Centre for further information about using this variable