The ONS Just Confirmed £37.3 Billion of UK Infrastructure New Work in 2025. Water, Sewerage and Electricity Make Up Nearly Half of It. Here Is Why Secondary Material Specification Has Never Mattered M

The ONS confirmed this week that UK new work infrastructure construction totalled £37.3 billion in 2025, up 3.2% on 2024. The increase was driven by water up 17.8%, sewerage up 74.8%, and electricity up 15.3%. Those three categories — the most corrosive, the most electrically demanding, and the most chemically aggressive secondary infrastructure environments in UK construction — now account for 46.5% of all new infrastructure work. The specification decisions being made on that £37.3 billion of new work will define the maintenance liabilities of the UK's infrastructure asset base for the next 30 to 50 years. Here is what that means for secondary material selection.

Published by Reinforce Technology  |  19 July 2026

The Office for National Statistics published its Infrastructure in the UK, Investment and Net Stocks report this week, confirming that new work infrastructure construction reached £37.3 billion in 2025, a 3.2% increase on 2024 in current prices (ONS, 2026). The growth was not evenly distributed across infrastructure categories. Water supply construction spending rose by 17.8% in 2025. Sewerage construction spending rose by 74.8%. Electricity infrastructure construction rose by 15.3%. Together, water, sewerage, and electricity new work accounted for 46.5% of all UK infrastructure new work in 2025, a concentration in precisely the three infrastructure sectors where the secondary material specification case for FRP over galvanised steel is strongest (ONS, 2026).

The ONS data also confirmed upward revisions to energy infrastructure investment, with market sector energy investment revised upwards by £5.8 billion compared with the July 2025 report, and energy infrastructure net stocks revised upwards by £67.5 billion in 2024 (ONS, 2026). The UK's infrastructure asset base is larger, more actively invested in, and more concentrated in the energy, water, and sewerage sectors than previous data suggested. And each additional pound of new work infrastructure construction in those sectors represents a secondary infrastructure specification decision that will either generate maintenance liabilities across a 30 to 50-year operational horizon or eliminate them.

The secondary infrastructure of water treatment works, sewerage facilities, and electricity installations, the grating, walkways, cable management, structural profiles, drainage, and access systems that run through and around the primary structure, is not visible in the ONS investment figures. It is a small fraction of total project cost, typically two to five percent of total capital expenditure on a new infrastructure installation. But it is the fraction whose material specification has the most disproportionate effect on operational maintenance cost. Galvanised steel secondary infrastructure in a water or sewerage environment that requires recoating at year ten and structural assessment at year fifteen adds recurring capital expenditure across a 50-year asset life. FRP secondary infrastructure in the same environment adds nothing after the day it is installed.

ONS confirmed UK new work infrastructure construction at £37.3 billion in 2025, with water up 17.8%, sewerage up 74.8%, and electricity up 15.3%. Those three sectors — the most corrosive and chemically demanding secondary infrastructure environments in UK construction — account for 46.5% of all new infrastructure work.

What the ONS Figures Are Actually Measuring

The ONS infrastructure investment report tracks new work construction output, which covers the installation of new infrastructure assets, and separately tracks repair and maintenance, which covers the cost of keeping existing assets operational. Both figures matter for understanding the secondary material specification decision, but they matter in different ways.

New work construction is where secondary material specification decisions are made. Every pound of new water, sewerage, and electricity infrastructure constructed in 2025 involved a secondary material specification decision, at design or procurement stage, that determined what grating, cable trays, structural profiles, and drainage systems went into the installation. That decision is made once, at construction stage, and its consequences compound across the operational life of the asset. A correct specification generates no secondary infrastructure maintenance cost across 30 to 50 years. An incorrect specification generates recurring maintenance cost that appears in future years as repair and maintenance expenditure, not as a capital line in the original project budget.

Repair and maintenance expenditure on UK infrastructure in 2025 was not broken out by the ONS at sector level in the July 2026 release, but the historical relationship between new work and maintenance across infrastructure sectors is well-established. NACE International's 2016 IMPACT study found that the global cost of corrosion was approximately 3.4% of GDP annually, with infrastructure accounting for a substantial proportion, and that 25 to 30% of corrosion costs could be eliminated through correct material selection and specification at the installation stage (NACE International, 2016). Applied to the UK's £37.3 billion of new work infrastructure in 2025, that finding suggests that material specification decisions made this year will determine whether a significant proportion of future maintenance expenditure is incurred or avoided across the UK's growing infrastructure asset base.

Water and Sewerage: The 74.8% and 17.8% Cases

Sewerage construction up 74.8% and water supply construction up 17.8% in a single year are extraordinary figures. They reflect the Ofwat AMP8 investment programme, which runs from 2025 to 2030 and represents £104 billion of total water sector capital expenditure, the largest water investment programme in UK history. AMP8 is building new sewage treatment works, upgrading storm overflow infrastructure following the Water (Special Measures) Act 2024, constructing new strategic water transfer infrastructure, and expanding treatment capacity in water-stressed regions. The ONS figures confirm that this investment programme is now in active construction at significant scale.

Water treatment and sewerage environments are among the most corrosive in UK civil infrastructure. The chemical environment of a water treatment works includes chlorine dosing for disinfection, hydrogen sulphide from biological treatment processes, and persistent humidity across all enclosed structures. Sewage treatment works face the full range of organic acid, hydrogen sulphide, and ammonia exposures that biological treatment generates, in addition to the corrosive washdown environments of operational maintenance. Secondary galvanised steel infrastructure in these environments depletes its zinc coating at accelerated rates, with effective coating life typically ten to fifteen years before recoating is required to prevent base metal corrosion (NACE International, 2016).

The 50-year design lives of the water and sewerage assets being built under AMP8 mean that secondary infrastructure specified in galvanised steel will require maintenance intervention at least twice, and potentially three or four times, across the asset's designed operational life. Each intervention involves scaffolding, surface preparation, coating application, curing, and quality inspection in an operational water or sewerage environment where production shutdown or containment requirements add substantially to the cost of what would be a straightforward industrial painting task in a non-operational environment.

FRP grating, cable trays, structural profiles, and drainage channels in water and sewerage environments provide corrosion-immune secondary infrastructure that requires no recoating at year ten, no structural assessment at year fifteen, and no replacement programme at year twenty-five. The chemical resistance of vinyl ester FRP to chlorine, hydrogen sulphide, and organic acids covers the full range of process chemistry encountered in water and sewerage treatment environments. The design life of FRP secondary infrastructure in these conditions is 50 years, matching the design life of the primary assets it serves (IntechOpen, 2022).

Electricity: The 15.3% Case

Electricity infrastructure construction up 15.3% in 2025 reflects the convergence of three simultaneous build programmes: the clean energy generation pipeline of solar farms, wind farms, and battery storage facilities building toward Clean Power 2030; the grid upgrade and reinforcement programme to connect and balance those new generation assets; and the substation and connection infrastructure of the 713 NESO-approved projects that received grid connection offers in June 2026. These three electricity infrastructure build programmes have different secondary infrastructure demands but share a common electrical sensitivity requirement: non-conductive secondary materials in proximity to high-voltage AC and DC systems.

Solar farm secondary infrastructure operates in outdoor agricultural or semi-industrial environments where corrosion from atmospheric exposure, ground moisture, and in coastal or upland locations salt air, attacks galvanised steel mounting frames and cable management. The DC cable management of a solar farm operates in a high-voltage direct current environment where conductive steel cable trays require earthing and bonding, and where arc propagation in a fault condition is a specific and documented safety risk that non-conductive FRP cable management eliminates (IntechOpen, 2022).

Grid substation and connection infrastructure secondary materials face similar electrical sensitivity requirements, with the additional complication of the electromagnetically sensitive instrumentation and protection systems that grid infrastructure uses. FRP secondary structural and cable management components are non-magnetic and non-conductive throughout, eliminating the electromagnetic interference that steel secondary infrastructure can introduce into the protection and metering systems of high-voltage grid infrastructure.

Battery storage secondary infrastructure faces the most specific electrical and chemical demands of any electricity sector application. Battery thermal runaway events generate hydrogen fluoride gas, organic solvent vapours, and intense heat. Secondary infrastructure in battery storage environments must be non-sparking in the gas-exposed environment adjacent to battery cells, corrosion-resistant to the chemical exposure of electrolyte leakage and thermal runaway products, and specified in materials that do not contribute to fire propagation in a thermal runaway event. Fire-retardant FRP formulations address the non-sparking and corrosion resistance requirements while providing significantly improved fire performance over standard FRP formulations.

Water up 17.8%, sewerage up 74.8%, and electricity up 15.3% in 2025. These are the three UK infrastructure sectors with the most demanding secondary material environments — corrosive, electrically sensitive, and designed for 30 to 50-year operational lives. The specification decisions made on this year's £37.3 billion of new work will define maintenance liabilities for decades.

The Maintenance Liability That the ONS Figures Do Not Show

The ONS infrastructure investment and net stocks report tracks capital formation — the creation of new infrastructure assets and the depreciation of existing ones. It does not track the maintenance expenditure that incorrect secondary material specification will generate across the operational lives of the assets being built today. That expenditure will appear in future years' repair and maintenance figures, attributed to the assets built in 2025, without any visible connection to the specification decisions made at their construction stage.

This temporal disconnection between specification decision and maintenance consequence is the fundamental market failure in secondary infrastructure specification. The engineer or procurement manager who specifies galvanised steel secondary infrastructure for a new water treatment works in 2025 will not be the person managing the recoating programme in 2035. The budget that bears the maintenance cost in 2035 is not the construction budget that saved money by specifying steel in 2025. The accountability for the whole-life cost of the specification decision is structurally separated from the authority to make it, and this separation consistently produces specification decisions that optimise for purchase price rather than lifecycle cost.

The peer-reviewed lifecycle cost evidence is unambiguous. A life cycle cost analysis found approximately 50% lifecycle cost savings for GFRP versus steel over long study periods, driven by the elimination of corrosion-related maintenance and replacement across the asset's operational life (Younis, Ebead and Judd, 2018). At the scale of £37.3 billion of annual new infrastructure work in the UK's three most corrosive sectors, the aggregate maintenance cost implications of that specification decision are a very large number. The ONS will report the capital formation correctly. The maintenance liability generated by incorrect specification will accumulate quietly in future repair and maintenance budgets, invisible to the infrastructure investment statistics but entirely predictable from the material specification decisions being made today.

The £725 Billion Pipeline and the Compounding Effect

The government's 10-Year Infrastructure Strategy published in June 2025 identified £725 billion of planned infrastructure investment over the coming decade. The ONS July 2026 figures confirm that delivery against that strategy is accelerating: 2025 new work was up 3.2%, and the concentration in water, sewerage, and electricity reflects the active delivery of the AMP8 water investment programme and the clean energy build-out simultaneously. If 2026 and subsequent years continue at similar or higher investment levels, the annual secondary material specification decisions being made across the UK infrastructure pipeline will compound into a very substantial accumulated asset base whose whole-life maintenance profile will be determined by the specification choices made during this decade of peak infrastructure investment.

Getting those specification choices right, across every water treatment works, every solar farm cable management system, every sewage treatment works grating installation, and every grid substation walkway, is the secondary infrastructure challenge that the ONS figures make visible in aggregate but that plays out individually on every project in the pipeline. FRP is the specification that eliminates the maintenance liability from each of those individual decisions, across the three infrastructure sectors that are growing fastest and that present the most demanding secondary material environments in UK construction.

£37.3 billion of new infrastructure work in 2025. £725 billion planned over the next decade. Water, sewerage, and electricity accounting for nearly half of current new work, in the most corrosive and electrically demanding secondary infrastructure environments in the UK. The specification decisions being made on those projects today will define maintenance liabilities that appear in ONS repair and maintenance figures for the next 30 to 50 years. FRP secondary infrastructure eliminates those liabilities. The ONS data makes the scale of what is at stake impossible to ignore.

Reinforce Technology FRP Products for UK Infrastructure

Reinforce Technology supplies FRP cable trays, grating, structural profiles, drainage, solar frames, and perimeter fencing for water, sewerage, and electricity infrastructure across the UK. Corrosion-immune in the chemical environments that the ONS's fastest-growing construction sectors present, non-conductive in the electrical environments of grid and solar infrastructure, and maintenance-free across the 30 to 50-year design lives that the assets being built under the UK's current infrastructure investment programmes are designed to deliver.

Contact us to discuss your project and the correct FRP secondary infrastructure specification for your application, environment, and operational horizon.

Final confirmation of suitability for any specific application remains the responsibility of the appointed project engineer. ONS data cited is from the July 2026 publication and reflects construction output data for 2025. Reinforce Technology provides technical guidance and material recommendations based on information supplied to us.

References

IntechOpen (2022) 'Fibre-Reinforced Polymer (FRP) in Civil Engineering', in IntechOpen Engineering Series. Available at: https://www.intechopen.com/chapters/84203 [Accessed: 19 July 2026]. [Non-conductive and corrosion-immune properties; 50-year design life in corrosive environments; non-sparking behaviour].

NACE International (2016) International Measures of Prevention, Application and Economics of Corrosion Technology (IMPACT). Houston, TX: NACE International. Available at: http://impact.nace.org/economic-impact.aspx [Accessed: 19 July 2026]. [Global corrosion cost 3.4% of GDP; 25 to 30% avoidable through correct material specification; galvanised coating life 10 to 15 years in aggressive environments].

ONS (2026) Infrastructure in the UK, Investment and Net Stocks: July 2026. Office for National Statistics. Available at: https://www.ons.gov.uk/economy/economicoutputandproductivity/productivitymeasures/articles/developingnewmeasuresofinfrastructureinvestment/july2026 [Accessed: 19 July 2026]. [New work infrastructure construction £37.3 billion in 2025, up 3.2% on 2024; water up 17.8%; sewerage up 74.8%; electricity up 15.3%; water, sewerage and electricity combined 46.5% of all new work; energy market sector investment revised upwards by £5.8 billion; energy net stocks revised upwards by £67.5 billion].

ScienceDirect (2025) 'Sustainable composites for metal replacement: Environmental assessment and material selection of fiber-reinforced polymer across industries', ScienceDirect, doi: 10.1016/S2667-3789(25)00051-3. Available at: https://www.sciencedirect.com/science/article/pii/S2667378925000513 [Accessed: 19 July 2026]. [Pultruded GFRP manufacturing emissions approximately 60 to 70% lower per tonne than primary steel, cradle-to-gate, EuCIA data].

Younis, A., Ebead, U. and Judd, S. (2018) 'Life cycle cost analysis of structural concrete using seawater, recycled concrete aggregate, and GFRP reinforcement', Construction and Building Materials, 175, pp. 135-144. doi: 10.1016/j.conbuildmat.2018.04.183. [Approximately 50% lifecycle cost saving for GFRP versus steel over long study period].