NUAR and the CDM Liability: What Every Asset Owner Needs to Know

The National Underground Asset Register (NUAR) went live across England in 2023, aggregating utility location data from over 700 asset owners into a single API. For the first time, a groundworker or design engineer can query underground assets — gas, water, electric, telecoms — without calling each utility individually.

On the surface, this is transformative. In practice, the data carries access conditions that most contractors have not read and their legal teams have not war-gamed.

The CDM 2015 pre-construction information duty

Under CDM 2015 Regulation 4, clients and principal designers have a duty to compile and provide pre-construction information that includes information about the state of underground services at the site. Until NUAR, this typically meant formal utility records requests — a process with a clear paper trail and explicit warranties from each asset owner.

NUAR replaces much of that workflow. But the NUAR licence, governed by the Geospatial Commission's hub terms (pre-2020 versions still operative for many hub data contributors), prohibits "commercial exploitation" of the data. The question regulators and insurers will eventually ask is whether a contractor's CDM-mandated use of NUAR data constitutes commercial exploitation.

KEY RISK

If a contractor derives a safety-critical pre-construction information pack from NUAR data, and that pack later proves incorrect, the question of who bears liability — the contractor, the asset owner, or the Geospatial Commission — is currently unresolved in UK case law.

What the current NUAR terms actually say

The Geospatial Commission's NUAR Licence (version current as of Q1 2026) permits access for "street works planning and avoidance of utility strikes." It does not explicitly permit: embedding NUAR data into contractor deliverables handed to clients; deriving secondary products (e.g. risk registers, method statements) from NUAR data that are then sold or included in commercial bids; or long-term retention of downloaded records.

The Geospatial Commission has acknowledged this ambiguity in correspondence reviewed by ActiveSense. A formal consultation on updated secondary use permissions was expected in spring 2026 but had not been published as of April 2026.

• →Read the current NUAR terms before including NUAR-derived data in CDM documentation
• →Flag NUAR provenance explicitly in pre-construction information packs
• →Maintain parallel utility records from direct asset owner requests for high-risk projects
• →Monitor the Geospatial Commission consultation — expect new secondary legislation in 2026

The Innovate UK letter mechanism

One route available to organisations who need extended NUAR data permissions is the Innovate UK letter mechanism — a formal written agreement with the Geospatial Commission that can extend permitted use beyond the standard licence for specific commercial research or product development purposes.

ActiveSense has been in dialogue with the Geospatial Commission about this mechanism as it relates to NUAR data products. Organisations considering a NUAR-derived software product or analytics service should seek this agreement before launching.

OGL v3 and synthetic data

One practical workaround gaining traction is using NUAR data solely for model training and validation, then publishing results under Open Government Licence v3 — which does permit commercial use — provided the published output does not constitute a "substantial part" of the original NUAR dataset.

This approach requires careful legal architecture but is increasingly how geospatial data product companies are navigating the NUAR licensing terrain.

Practical steps for contractors now

Until the Geospatial Commission publishes its updated secondary use framework, contractors should treat NUAR data as operationally useful but legally constrained. The safest position is to use NUAR for internal strike avoidance planning while maintaining direct utility records requests for any data that will appear in client-facing CDM documentation.

If your organisation is building a product that depends on NUAR access, speak to the Geospatial Commission directly and document that conversation. ActiveSense can assist with data architecture advice for NUAR-adjacent products.

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ActiveSense provides architecture reviews, CDM/LDM/PDM design, GEMINI 2.3 compliance programmes, and NUAR advisory across public sector and energy clients. Available via G-Cloud.