# School Construction Cost Planning: St Helens, United Kingdom > St Helens school cost planning using the World Bank ICP 2021 national construction price-level index of 155.3, plus a GeoNames-based local comparable-search shortlist. - Canonical: https://harth.build/resources/construction-costs/school-construction-cost-st-helens-gb/ - Last updated: 2026-09-15 - Data source: National screening observation from the [World Bank ICP 2021 API](https://api.worldbank.org/v2/sources/90/country/GBR/classification/PX.WL/series/1501200/time/YR2021/data?format=json) and [ICP data documentation](https://www.worldbank.org/en/programs/icp/data); locality and population from the [GeoNames GB dump](https://download.geonames.org/export/dump/GB.zip) (CC BY 4.0 snapshot 2026-08-26, GeoNames ID 2638785). The PLI is not a city cost/m² rate, current escalation series or tender estimate. ## Key facts | Fact | Value | | --- | --- | | National construction PLI | 155.3 (World Bank ICP 2021; World = 100) | | Screening ratio to world | 1.553 (dimensionless PLI ÷ 100; not a city location factor) | | Locality reference | 53.4500, -2.7333 (GeoNames ID 2638785) | | Snapshot population | 183,200 (44 of 50 listed United Kingdom places) | | Nearest listed peer | Warrington · 12 km (great-circle distance between GeoNames reference points) | | Estimate currency | GBP (obtain a current local rate and named base date) | ## Direct answer For early school construction cost planning in St Helens, the World Bank ICP reports a 2021 United Kingdom construction price-level index of 155.3, with the world equal to 100. This is a national comparison—not a St Helens GBP/m² rate or tender estimate—so replace it with current local evidence before budgeting or procurement. The observation covers construction across United Kingdom in 2021; it does not measure a St Helens market basket or current school tenders. GeoNames 2638785 records the locality at 53.4500, -2.7333, with snapshot population 183,200. That ranks St Helens 44 of 50 listed places, while Warrington is the nearest listed peer at about 12 km. Use these facts only to plan the comparable search. Obtain current local rates on a consistent area basis, then reconcile scope, taxes, fees, contingency and escalation. Retain the source, base date and reviewer when local evidence replaces the screening ratio. *Content and cited inputs reviewed by [Scott Barrington](https://nz.linkedin.com/in/barrington), Harth founder and architectural technology specialist · Published 2026-08-26 · Updated 2026-09-15.* ## What does the 155.3 construction index mean? The World Bank ICP 2021 construction PLI for **United Kingdom is 155.3**, compared with a world benchmark of 100. It is a national spatial price comparison assembled for the 2021 reference year. It does not say that school work in St Helens costs 1.553 times a current world rate. ## Which St Helens inputs are known? The reproducible locality point is **53.4500, -2.7333** (GeoNames 2638785). Its snapshot population is **183,200**, ranked 44 of 50 listed places; GeoNames classifies it as a second-order administrative seat in administrative area ENG. These facts shape the local comparable search, not the price. ## What must a project estimate add? For a St Helens school project, reconcile teaching spaces, specialist rooms, safeguarding, sports provision and external works. Use a consistent gross-floor-area basis and record the following before reliance. | Estimate field | Screening record | Project requirement | | --- | --- | --- | | National context | ICP 2021 PLI 155.3 | Retain only as dated cross-country context | | Local GBP/m² rate | Not supplied | Current comparable with named source and base date | | Area and scope | Gross floor area; scope unresolved | Measurement standard, specification and procurement route | | Additions | Not supplied | Taxes, fees, site work, contingency and escalation | | Review | Automated source and arithmetic QA | Qualified local cost review | ## St Helens comparable-location search screen This shortlist is computed from the checked GeoNames snapshot. Distance and population help prioritize where to request comparables; neither is used as a cost multiplier. | Listed place | Great-circle km from St Helens | Snapshot population | Admin area | | --- | ---: | ---: | --- | | Warrington | 12 | 172,330 | ENG | | Wigan | 12 | 175,405 | ENG | | Liverpool | 17 | 496,770 | ENG | | Birkenhead | 20 | 325,264 | ENG | | Manchester | 33 | 568,996 | ENG | | Sutton | 290 | 187,600 | ENG | | Ipswich | 304 | 178,835 | ENG | | Croydon | 291 | 173,314 | ENG | ## Price-level normalization worksheet For a validated reference rate **R** from a country with construction PLI **P**, the transparent screening calculation is **R × (155.3 ÷ P)**. At P = 100 the dimensionless ratio is 1.553; no world cost rate is asserted. Keep the reference rate's currency, base date, area basis and scope attached. | Input | Recorded value | Release condition | | --- | --- | --- | | Target national PLI | 155.3 (World = 100, 2021) | Screening context only | | Reference construction PLI P | User-supplied from the same ICP classification/year | Must match reference rate country | | Validated reference rate R | User-supplied | Named source, currency, date, area and scope | | Local St Helens adjustment | Not asserted | Replace with current local comparable evidence | | Result status | Screening normalization | Not a budget, quote or tender estimate | ## Where can you explore related guidance? - [Explore all construction costs guidance](https://harth.build/resources/construction-costs.md) - [Office Construction Cost Planning: St Helens, United Kingdom](https://harth.build/resources/construction-costs/office-construction-cost-st-helens-gb.md) - [House Construction Cost Planning: St Helens, United Kingdom](https://harth.build/resources/construction-costs/house-construction-cost-st-helens-gb.md) - [Retail Construction Cost Planning: St Helens, United Kingdom](https://harth.build/resources/construction-costs/retail-construction-cost-st-helens-gb.md) - [School Construction Cost Planning: Liverpool, United Kingdom](https://harth.build/resources/construction-costs/school-construction-cost-liverpool-gb.md) - [All construction costs guidance for United Kingdom](https://harth.build/resources/construction-costs/united-kingdom.md) - [Climate Design Data: St Helens, UK](https://harth.build/resources/climate-data/climate-design-data-st-helens-gb.md) - [Sun Path: St Helens, UK](https://harth.build/resources/solar-data/sun-path-st-helens-gb.md) ## Sources and method National screening observation from the [World Bank ICP 2021 API](https://api.worldbank.org/v2/sources/90/country/GBR/classification/PX.WL/series/1501200/time/YR2021/data?format=json) and [ICP data documentation](https://www.worldbank.org/en/programs/icp/data); locality and population from the [GeoNames GB dump](https://download.geonames.org/export/dump/GB.zip) (CC BY 4.0 snapshot 2026-08-26, GeoNames ID 2638785). The PLI is not a city cost/m² rate, current escalation series or tender estimate. ### Source links - [api.worldbank.org](https://api.worldbank.org/v2/sources/90/country/GBR/classification/PX.WL/series/1501200/time/YR2021/data?format=json) - [worldbank.org](https://www.worldbank.org/en/programs/icp/data) - [download.geonames.org](https://download.geonames.org/export/dump/GB.zip) ## Frequently asked questions ### Does the 155.3 index give a school cost per m² for St Helens? No. 155.3 is the World Bank ICP 2021 national construction price-level index for United Kingdom, with the world equal to 100. It is a cross-country screening statistic, not a St Helens GBP/m² rate, escalation index, quote or tender estimate. ### How should a St Helens school estimate replace this screening benchmark? Collect current St Helens comparables on a consistent gross-floor-area basis, reconcile teaching spaces, specialist rooms, safeguarding, sports provision and external works, and state base date, currency, taxes, fees, site work, contingency and escalation. A qualified local cost professional should review the resulting project estimate. --- - Continue in Harth (open this topic in the Harth agent): https://app.harth.build/agent?context=%2Fresources%2Fconstruction-costs%2Fschool-construction-cost-st-helens-gb%2F - View this page in a browser: https://harth.build/resources/construction-costs/school-construction-cost-st-helens-gb/ - All resources for agents: https://harth.build/llms.txt