Data and methodology

1. More detail on the data and methodology can be found in the explanation of quarterly housing statistics note and data quality, sources and suitability notes.
2. The data are sourced from local authority administrative systems for local authority and private sector housebuilding, the Scottish Government Housing and Regeneration Programme (HARP) system for the Affordable Housing Supply Programme. Housing association data are drawn by the Scottish Government from data on the administration of housing support grants through the Affordable Housing Investment Programme (AHIP).
3. Data for the affordable housing supply programme include Section 75 units receiving some form of government funding. Data are not available to estimate the number of affordable homes delivered without central government funding in Scotland. Each local authority will have a different approach to the supply of affordable housing, and there may be affordable housing units that will not be reported as affordable housing.
4. In general, for local authority and private sector housebuilding, new build information is provided for starts (when the foundations are begun) and completions (when a building inspector deems the property complete). Completions and starts are reported on a unit-by-unit basis each quarter – rather than when a full site is completed or has started. This differs to the affordable housing supply programme (AHSP), where completions are only reported when a full site has been delivered. Generally, this means that completed units provided through local authorities will be reported earlier than the AHSP reports.
5. In general, the number of starts will be a strong indicator of the likely trend in completions over the longer term, but there may well be differences over the short and medium term depending on factors such as the housing market, economic climate, access to finance, and speed of construction.
6. A wide range of factors can influence the length of time it takes for a new private dwelling to be constructed, including the type of property (house, flat etc.), and the overall size of the site. Depending on the size of the site, the average time from start to completion of the entire site can range from anywhere between around 1.5 years to 2.75 years. Individual homes, or blocks of homes, might be completed in shorter timescales if parts of the site are completed in advance of the rest.
7. Private sector construction activity includes not only homes built for private sale but also some homes which are subsequently used in the affordable housing sector and self-build activity by local builders.
8. The figures have not been seasonally adjusted and so commentary tends to compare the latest 12-month period with the previous 12-month period, or the latest quarter with the same quarter in the previous year.
9. It should be noted that the amount of all-sector new housebuilding activity recorded in the quarters January to March 2020 and April to June 2020 will have been impacted by the introduction of measures to reduce the spread of the coronavirus (COVID-19) from mid-March to late June, in which non-essential construction activity stopped and home buyers were advised to delay moving to a new home where possible, after which there has been a phased re-start of supply activity.
10. Also note for housing association new build figures presented prior to April 2018 that approvals are used as a proxy for housing association new build starts due to data quality considerations in the historic series for starts.
11. A small number of local authorities have private-led new build data estimated due to delays in the provision of this data. These are:

• East Dunbartonshire, since 2021 Q3.
• South Ayrshire, since 2024 Q1.
• Stirling, since 2021 Q4.
• Na h-Eileanan Siar, since 2023 Q4.

In the December 2024 publication estimates have been updated for several local authority’s as follows:

• Aberdeen City local authority starts and completions up to 2024 Q3 (the latest quarter) from 2022 Q1.
• Aberdeen City private led starts and completions up to 2024 Q3 (the latest quarter) from 2023 Q4.
• East Dunbartonshire, private-led starts and completions have been updated up to 2021 Q2 from 2020 Q4.
• South Ayrshire private-led starts and completions have been updated to 2023 Q4 from 2022 Q4.

The estimates in previous publications have been revised in this publication made for local authority new housebuilding starts and completions. Further details of these revisions, along with the impact on national totals, are detailed in Tables R1a to R7b in the Supporting Charts and Tables Excel document.

12. As with previous publications:

• the estimates of private-led new build activity for local authorities with missing data are each based on an average of the preceding four quarters, with an adjustment made to account for different overall levels of construction activity seen in particular quarters, which is based on the aggregate trends from the local authorities who have provided data across the period in question.
• Highland starts data has been estimated since 2006 Q3, based on the completions data provided by the authority as an estimated level of contribution to national level new build housing starts. In this publication, starts for Highland have been revised back to 2006 Q3 due to a data processing error. This in turn will have updated all private led starts for Scotland.
• Glasgow private-led figures for the period Q2 2020 to Q1 2022 have been based on data provided by Glasgow Council for all-sector figures across this period, from which we have derived the private-led component by netting off housing association starts and completions based on separate social sector new build figures taken from HARP system. Since Q2 2022 starts and completions by sector are now based directly on the data provided.

13.  The ‘old style’ affordable housing supply summary excel tables have been discontinued to avoid duplication. The published affordable housing supply summary tables include data breakdowns additional to the ‘old style’ tables but are structured slightly differently to the ‘old style’ tables. Please get in contact with us if this change causes significant concern.