Construction Output YoY

Construction Output YoY is the 12-month change in the ONS bulletin Construction output in Great Britain. It tracks building and engineering work done in the month, charged to customers and excluding VAT and payments to hired subcontractors. It covers Great Britain only, meaning England, Scotland and Wales, using a monthly survey of about 8,000 builders plus VAT records for small firms. It excludes Northern Ireland, developers, future orders and opinion surveys, and counts gross work, not GDP (gross domestic product) value added.

The Office for National Statistics has run the monthly survey since January 2010. Its roots run back to 1955, and firms with 100 or more staff are fully counted.

ONS records work done during each calendar month and publishes the result about 6 weeks after month end at 7:00am UK time. Each release appears with the monthly GDP estimate, the Index of Services and the Index of Production, plus output, price, orders and annual datasets. Revisions follow the National Accounts Revisions Policy, as late survey and tax returns replace estimates and calendar and price adjustments are updated. It headlines monthly and 3-month growth, sector contributions and the £ million level, with YoY read from the adjusted series and no threshold.

New work drives swings while repair and maintenance steadies the total, across 9 sectors in 2 groups.

• Private new housing: new homes built for private clients, the largest new-work sector.
• Public new housing: new homes built for public-sector clients.
• Infrastructure new work: water, energy, roads, rail, harbours and other civil projects.
• Private commercial new work: offices, shops and private health, education and leisure buildings.
• Public other new work and private industrial new work: schools, hospitals and offices for public clients plus factories and warehouses.
• Repair and maintenance: upkeep of public housing, private housing and non-housing buildings.

The February 2021 bulletin, released April 13, 2021, shows why the 12-month view matters. Monthly output rose 1.6% to £13,319 million, yet stood 4.3% or £598 million below February 2020. New work was 7.8% below February 2020 while repair and maintenance was 2.2% above it. Private commercial new work rose 4.0% on the month while infrastructure new work fell 3.4%.

The same release revised 2020 annual growth to negative 14.0%, the largest yearly fall since annual records began in 1997. A monthly gain can hide a weak 12-month position, with repairs leading and new building lagging.

1. Collect: Each sampled firm reports work done in the month by type, excluding VAT and hired subcontractor payments, including work built for sale or lease. Missing replies are chased, then imputed (estimated) and replaced when late returns arrive.
2. Weight to population: Small-firm strata use design weights (grossing for sample chance) and calibration weights (matching VAT turnover), while large firms are fully counted. VAT returns cover small firms sampled thinly.
3. Deflate to volume: Current-price totals are divided by quarterly price indexes (OPIs, indexes tracking building costs) to give inflation-adjusted chained volume. For example, £200 million at current prices over an index of 125.0 gives £160 million in volume. Weights update each year and link across years.
4. Compare: Volumes are seasonally adjusted with X-13-ARIMA-SEATS (a seasonal filter) at sector level, then summed to all work. YoY equals the index divided by its value 12 months earlier minus 1, times 100. For example, £2.0 million weights to £200 million, deflates to £160 million, adjusts to £156.9 million, index 104.6 against 100.0, or 4.6% YoY.