Experimental dwelling estimates
We designed this work as a proof of concept, to see whether existing data sources could be used to produce estimates of private residential dwelling completions and therefore dwelling stock at a subnational (territorial authority) level, on a quarterly basis. This would allow for an understanding between Census of Population and Dwelling periods of the housing supply available around New Zealand and the amount of construction activity being undertaken to build houses.
We are releasing these experimental estimates to stimulate discussion about how dwelling completions and subnational dwelling stock could be measured in future, and to gather feedback from you on the value of this work and improvements that could be made to the methodology.
You can download the following:
- Proof of concept: Subnational dwelling completions and stock estimates (PDF, 34 pages, 951kB) – an introduction to research undertaken, methodologies used, results produced, and caveats around this experimental release.
- Proof of concept: Subnational dwelling completions and stock estimates – results (Excel, 9 sheets, 117kB)
We’d like your feedback about:
- How useful this information is
- What you might use these estimates for
- What additional information you would like included
- What enhancements would make these estimates most useful
- Any suggestions for improvement
To provide feedback, please click the ‘Give feedback’ button above.
If you would like to discuss your feedback further or would like to speak to us directly, please contact Melissa McKenzie, firstname.lastname@example.org, or Mark Darbyshire, email@example.com.
What you’ll see
Dwelling completion estimates produced are for the March 1998 quarter to the March 2017 quarter, while dwelling stock estimates cover the March 2001 quarter to the March 2017 quarter.
Data includes counts of unique residential private dwellings (eg the sum of apartment units, stand-alone houses, townhouse units, retirement village units). No adjustment is made for seasonal effects.
Dwellings – new self-contained private residences. Examples include houses, apartments, townhouses, granny flats, and licence-to-occupy retirement village units.
Completions – the number of new dwellings constructed to the point of being reported in the Quarterly Building Activity Survey (QBAS) as finished, or where the Christchurch City Council has recorded their final council inspection undertaken, or issued a code compliance certificate.
Stock – the number of private dwellings available, including previously existing stock as well as recent completions.
Cancellation rate – the proportion of dwelling consents issued which do not progress to the completion.
Lag – the time between when a dwelling consent is issued and when it is completed.
Work in progress – the proportion of dwelling consents that have not been cancelled and are yet to be completed.
The dwelling completions and stock estimates have been made available as quarterly estimates at the territorial authority (TA) level – 67 areas defined under the Local Government Act 2002 and related documents.
Cancellation rates and lags have been made available as annual estimates at the National (New Zealand total level).
Confidentiality principles have not needed to be applied to these estimates, as the modelled component removes the potential for exact dwellings to be identified. However no breakdowns are provided by building type which would make projects identifiable, and no financial data has been utilised or released.
This work was designed as a once-off proof of concept. No commitment has been made to any future work either utilising the current experimental methodology or alternative methodology at this stage.
The data feeding into these estimates includes: administrative data (building consents issued; and final inspection and code compliance data from Christchurch City Council’s Monitoring and Research team), and data collected on individual construction projects via the Quarterly Building Activity Survey.
Data likely to change: These estimates are an experimental proof of concept. Any change in methodology or data sources used would alter the results. This data should not be considered final, and we advise against using the data in decision-making.
A list of known issues, considerations, and already identified improvements can be found in the attached report.
Published 6 July 2017