Construction output in Great Britain: August 2025

• Total construction output is estimated to have grown by 0.3% in the three months to August 2025.

• Over the three-month period, new work fell by 0.4%, and repair and maintenance grew by 1.3%.

• At the sector level, five out of the nine sectors grew in the three months to August 2025; the main contributor to the increase was private housing repair and maintenance, which grew by 5.6%.

• Monthly construction output is estimated to have fallen by 0.3% in August 2025, after showing no growth in July 2025 (revised down from 0.2% growth in our previous publication).

• The decrease in monthly output in August 2025 came solely from a decrease in repair and maintenance (1.5%), as new work increased on the month (0.5%).

Construction output estimates

Construction output estimates are monthly estimates of the amount of output chargeable to customers for building and civil engineering work done in the relevant period, excluding Value Added Tax (VAT) and payments to subcontractors.

Seasonally adjusted estimates

Seasonally adjusted estimates are derived by estimating and removing calendar effects (for example, leap years, such as 2024) and seasonal effects (for example, decreased activity at Christmas because of site shutdowns) from the non-seasonally adjusted estimates.

Value estimates

The value estimates reflect the total value of work that businesses have completed over a reference month.

Volume estimates

The volume estimates are calculated by taking the value estimates and adjusting to remove the impact of price changes.

Quality and methodology

More quality and methodology information (QMI) is available in:

• our Construction output QMI

• our Construction output price indices (OPIs) QMI

• our New orders in construction QMI

Reasons for revisions to construction output in this release

This release contains revisions for all periods. The revisions up to June 2025 are consistent with those published in our Gross domestic product (GDP) quarterly national accounts, UK: April to June 2025 bulletin, published on 30 September 2025. This is consistent with the National Accounts Revisions Policy. Additionally, we have updated the base year to 2023. Revisions in this release are a result of:

• revisions in the nominal data; this includes revisions to the survey data

• revisions to seasonal adjustment factors, which are re-estimated every month and reviewed annually

• revisions to the input series for the Construction output prices indices (OPIs)

For further information on the revisions profile, see our Output in the construction industry revisions triangle (one-month growth) dataset and our Output in the construction industry revisions triangle (three-month growth) dataset.

Pausing of producer prices publications

Business prices data with corrected chain-linking methods have been used in the monthly GDP dataset for Producer Price Indices (PPI), Import Prices Indices (IPI) Export Price Indices (EPI), and Service Producer Price Indices (SPPI) for all periods in this release. The quarterly SPPI estimates are splined to months for use in monthly GDP calculations.

Any further updates to price data following the restart of the monthly business prices publication will be incorporated in GDP estimates in line with our national accounts revisions policy.

Further information on the chain-linking error in the producer prices dataset are detailed in our Methods update for Producer Price Indices (PPI) and Service Produce Prices Indices (SPPI) published on 10 July 2025.

Seasonal adjustment

Our monthly construction estimates are seasonally adjusted. Seasonal adjustment is the process of removing the variations associated with the time of year, or the arrangement of the calendar, from a data time series.

Construction estimates, as for many data time series, are difficult to analyse using raw data because seasonal effects dominate short-term movements. Identifying and removing the seasonal component leaves the trend and irregular components.

The Office for National Statistics (ONS) uses the X-13-ARIMA-SEATS approach to seasonal adjustment. Seasonal adjustment parameters are monitored closely and regularly reviewed. For more information, please see our Seasonal adjustment methodology page.

In our monthly estimates, seasonal adjustment is applied at the sector level and the seasonally adjusted series are aggregated to create estimates by total output. As part of our quality assurance approach, residual seasonality checks are regularly completed by our time series analysis team on both the directly seasonally adjusted series and the indirectly derived aggregate time series.

Subnational and subsector construction output

Data on new orders supplied by Barbour ABI are used to model the breakdown of the overall output figures for Great Britain into the lower-level and regional data. This is shown in Tables 1 and 2 of our Output in the construction Industry: subnational and subsector dataset. More detail is available in our Quality assurance of administrative data used in construction statistics methodology.

Bias adjustment

Typically, since the move to monthly gross domestic product (GDP) estimates, an adjustment to address any bias in survey responses for construction output is applied to the early construction output monthly estimates. We show this in our Improvements to construction statistics: Addressing the bias in early estimates of construction output, June 2018 article.

Response rates for August 2025 showed improvement compared with levels in recent years since the coronavirus (COVID-19) pandemic. The survey turnover response rate for August 2025 was 79.9%. This follows a response rate of 73.0% in July and 77.8% in June. We have continued not to apply a bias adjustment since May 2020 while we review this approach. More information on our response rates is available in our Output in the construction industry dataset.

Differences with Monthly GDP construction estimates

In Blue Book 2021, we introduced a new framework to improve how we produce volume estimates of GDP for balanced years as part of the supply use process. This was explained in our Producing an alternative approach to GDP using experimental double deflation estimates article. This framework included the implementation of double-deflated industry-level gross value added (GVA) for the first time. This improvement was reflected in the GDP quarterly national accounts, UK: April to June 2021 bulletin and datasetand GDP monthly estimate, UK: August 2021 bulletin for the first time.

As a result, volume estimates in the monthly GDP and construction outputs releases will differ for the period 1997 to 2020. This is because the construction publication measures the volume of construction work (output), while the GDP series measures GVA (that is, output minus intermediate consumption). Construction estimates will align, but on a growth basis from January 2021 onwards.

Information and indicative effects of this change to industry-level GVA volume can be found in our Impact of double deflation on industry chain volume measure annual estimates article and our Impact of Blue Book 2021 changes on quarterly volume estimates of gross domestic product by industry article.

Accredited official statistics

These accredited official statistics were independently reviewed by the Office for Statistics Regulation in March 2019. They comply with the standards of trustworthiness, quality and value in the Code of Practice for Statistics and should be labelled "accredited official statistics".