Data and Methodology

This document should be read along with the explanatory notes on data sources and quality can be found in the Housing Statistics webpages.

The statistics break down new build construction activity into private-led and social sector starts and completions, with the social sector further broken down between local authority and housing association activity.

The figures are sourced from local authority administrative systems and the Scottish Government Housing and Regeneration Programme (HARP) system. Private sector construction activity includes not only homes built for private sale but also some homes which are used in the affordable housing sector and self-build activity by local builders.

New build information is provided for starts (when the foundations are begun) and completions (when a building inspector deems the property complete).

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.

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.

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.

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.

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. From this publication onwards, housing association starts data is now used as the basis for housing association starts figures for the financial year 2018/19 onwards. More detail is available at the end of the social sector new housebuilding section.

A small number of local authorities have private-led new build data estimated due to delays in the provision of this data. These are:

• Aberdeen City, private-led starts and completions since 2023 Q2.
• East Dunbartonshire, private-led starts and completions since 2020 Q4.
• Dundee City, private-led starts and completions since 2023 Q1.
• South Ayrshire, private-led starts and completions since 2022 Q1.
• Stirling, private-led starts and completions since 2022 Q1

We are working with these local authorities to obtain these figures and aim to replace these estimates with actual figures in future publications.

As with previous publications, the estimates of private-led new build activity 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.

Also as with previous publications, 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.

Additional estimates have been made for local authority led new housebuilding starts and completions for Highland since 2020 Q4 due to a delay in the return, Edinburgh for 2023 Q2, as well as Aberdeen City and South Ayrshire since 2022 Q2. As with previous estimates for local authority led new housebuilding figures, these estimates are based on separate starts and completions figures taken from the Scottish Government Housing and Regeneration Programme (HARP) system.

As with previous publications, 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 the Scottish Government Housing and Regeneration Programme (HARP) system. More recently provided quarters of data for the periods Q2 2022 onwards include a split for the private-led component of the data, and so figures presented across this period are now based directly on the data provided rather than through a netting off calculation.

A number of additional historic corrections provided by local authorities have also been made, for example where more up-to-date data for activity related to previous quarters has come to light, with further details on these changes available in the Excel webtables.

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.