The Department for Transport’s new Heathrow Expansion Appraisal Report has put fresh numbers behind one of the UK’s largest potential infrastructure projects, showing major passenger, connectivity and local jobs benefits, but also a negative overall Net Present Value once monetised costs are included.
The June 2026 report supports the Government’s review of the Airports National Policy Statement and assesses Heathrow expansion through a Northwest Runway and associated terminal buildings. For the construction sector, the report points to a long-term aviation infrastructure pipeline, but also underlines that carbon, cost pass-through, surface access and delivery assumptions remain central to whether expansion can pass the Government’s tests.
The headline construction message is clear: Heathrow expansion remains a huge infrastructure opportunity, but the appraisal does not present it as a simple economic win. Passenger benefits are large, local jobs could be significant, yet the combined monetised appraisal remains negative across the tested scenarios.
Jump to: What this means | By the numbers | Construction pipeline | Carbon and cost risk | What happens next
What This Means
The DfT appraisal estimates passenger benefits from Heathrow expansion at between £25.3bn and £35.5bn. The lower figure applies where expansion costs are passed through to passengers, while the higher figure assumes no cost pass-through. When passenger benefits, additional government revenues and wider economic impacts are combined, total benefits rise to between £29.2bn and £42.4bn.
However, the report also states that when all monetised impacts are combined, the Net Present Value is negative. The range is from -£23.4bn under a no cost pass-through scenario using the UK carbon account, to -£62.5bn under a cost pass-through scenario using global carbon impacts.
That distinction matters. The report is not saying there are no economic benefits. It is saying the monetised benefits, environmental disbenefits, private sector costs, airline and airport profit impacts and carbon assumptions create a complex overall picture.
For contractors, consultants, aviation suppliers and infrastructure teams, the report keeps Heathrow expansion firmly alive as a project pipeline issue — but one that will remain exposed to political, environmental, financing and planning scrutiny.
By the Numbers
| Measure | DfT Appraisal Figure | Construction Relevance |
|---|---|---|
| Passenger benefits | £25.3bn to £35.5bn | Shows the scale of demand-side benefit behind the expansion case. |
| Total benefits | £29.2bn to £42.4bn | Includes passenger benefits, government revenues and monetised wider economic impacts. |
| Net Present Value | -£23.4bn to -£62.5bn | Highlights the challenge once monetised costs, carbon and private sector impacts are included. |
| Runway opening assumption | 2035 | Sets the broad programme horizon for runway construction and associated works. |
| Terminal capacity upgrades | 2038, 2049 and 2054 | Suggests a phased delivery pipeline beyond the runway itself. |
| Local jobs supported | Up to 61,000 by 2055 | Shows the potential local employment scale linked to airport operations and supply chains. |
A Long-Term Construction Pipeline
The report assumes Heathrow’s Northwest Runway becomes operational in 2035, but passenger volumes remain constrained until terminal capacity is delivered in later phases. The DfT identifies terminal capacity upgrades in 2038, 2049 and 2054. That phasing is important for the construction market. Heathrow expansion would not be a single runway project only. It would involve runway works, terminal buildings, connecting infrastructure, surface access measures, operational infrastructure, maintenance and renewals over a long appraisal period.
The report also states that the expansion must be privately financed and happen at no expense to the taxpayer. That means construction costs, financing costs and user charges will remain major issues in the final delivery model. For contractors, the opportunity is significant, but the procurement route, risk allocation, surface access obligations, carbon requirements and financing structure will matter as much as the headline project value.
Carbon, Cost Pass-Through and Environmental Risk
A major change from previous Heathrow appraisal work is that aviation carbon emissions are now included in the assessment, in line with current DESNZ guidance. The report considers both a UK carbon accounting perspective and a wider global impact perspective. The report says that under the no cost pass-through scenario, total benefits exceed monetised environmental disbenefits under both the UK carbon account and global impact approach with displacement. But under cost pass-through, environmental disbenefits outweigh total benefits.
For construction, the non-aviation carbon picture also matters. The appraisal retains earlier quantified estimates for surface access, construction and operations carbon, with construction carbon listed at 11.3 MtCO2e over the 60-year assessment period. That means future Heathrow construction packages would sit under intense scrutiny around materials, logistics, construction emissions, surface access, programme efficiency and long-term operational performance.
Related LCM Intelligence
Heathrow expansion sits inside the wider UK infrastructure and delivery-risk picture. See LCM’s London Construction Project Delivery Risk Report, London construction costs to 2030, and London stalled projects delivery tracker.
What Happens Next?
The report forms part of the evidence base for the draft Heathrow Expansion National Policy Statement consultation. It does not itself grant permission for the runway or finalise the construction programme. The DfT says it will be for a promoter to bring forward Heathrow expansion proposals that satisfy the Government’s four tests, including growth across the country, carbon, noise and air quality requirements.
For the construction sector, the next stage is therefore not only about whether Heathrow expansion remains politically supported. It is about whether the scheme can demonstrate deliverability, financeability, environmental compliance and a procurement model capable of handling one of the UK’s most complex infrastructure programmes. The new appraisal keeps Heathrow expansion on the table, but it also makes clear that the project will need to prove its case through evidence, not just strategic ambition.
Source Context and Editorial Note
This article is a London Construction Magazine news summary based on the Department for Transport’s June 2026 Heathrow Expansion Appraisal Report. The report updates the appraisal of Heathrow expansion through a Northwest Runway and associated terminal buildings, including passenger benefits, connectivity impacts, wider economic impacts, costs, environmental disbenefits and local jobs supported. Relevant source context: Department for Transport.
This article does not provide planning, financial, aviation, environmental or legal advice. Heathrow expansion remains subject to policy, planning, promoter proposals, environmental requirements, funding and future consent processes.
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Expert Verification & Authorship: Mihai Chelmus
Founder, London Construction Magazine | Construction Testing & Investigation Specialist |
