Construction output in Great Britain: April 2025

• Monthly construction output is estimated to have grown by 0.9% in April 2025; this is the third consecutive period of positive growth, following an increase of 0.5% in March 2025.

• The increase in monthly output in April 2025 came from increases in both new work and repair and maintenance, which grew by 1.4% and 0.3%, respectively.

• At the sector level, six out of the nine sectors grew in April 2025; the main contributors to the monthly increase were infrastructure new work and private housing repair and maintenance, which rose by 2.0% and 1.5%, respectively.

• Total construction output is estimated to have grown by 0.5% in the three months to April 2025; new work increased by 0.9%, and repair and maintenance grew by 0.1%.

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 no revisions to previously published data and is consistent with the National Accounts Revisions Policy.

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

As we announced in our statement on 21 March 2025, during work to improve the systems used to create the Producer Price Index (PPI) and the Services Producer Price Indices (SPPI), our quality assurance identified a problem with the chain-linking methods used to calculate the PPI and SPPI indices. For more information, please see our Producer prices publications update, released on 11 April 2025.

As these detailed price data are used within our calculations, along with gross domestic product (GDP), this may lead to impacts on the level of some sectors, with revisions to estimates likely in 2022 and 2023. At an aggregate level for GDP, these revisions should be offsetting to an extent, while taken alongside regular data deliveries. Early indications suggest that there will not be a notable change in the recent economic trends seen in these data, but we will update users once more information becomes available. We do not plan any changes to the publication timetable for output in the construction industry, however, we are pausing updates to the construction output price indices (OPIs) series until further notice. We will continue to use PPI, SPPI and the resulting Output Price indices (OPIs) estimates compiled under the current methodology in these publications until updated methods and data are available. We will provide further information on the likely effects as soon as is practicable. An error has been identified in the consumer price inflation measures for April 2025, as detailed in our Vehicle Excise Duty impact on Consumer Price Inflation statement. This error has no impact on monthly construction or GDP estimates for April 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 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.

Sub-national and sub-sector 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: sub-national and sub-sector 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 April 2025 showed improvement compared with levels in recent years since the coronavirus (COVID-19) pandemic. The survey turnover response rate for April 2025 was 71.6%. This follows a response rate of 72.7% in March and 79.7% in February. 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 dataset and 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".