NUAR questions and answers

The National Underground Asset Register (NUAR) is a repository of information relating to the pipes and cables buried beneath our streets.

NUAR standardises, centralises, and makes available privately and publicly owned data from hundreds of organisations about the location of underground utilities assets. NUAR is a secure, auditable, trusted, and sustainable platform.

It provides a consistent, interactive digital map of buried asset data, accessible when, where, and how it is needed, by those planning and executing excavations.

By improving access to underground asset data for authorised street works users, NUAR is improving the efficiency and safety of street works. This is envisaged to deliver over £400 million per year of economic growth through increased efficiency, reduced accidental damage, and reduced disruptions for citizens and businesses.

The ‘public beta’ version of the map is now live and covers the whole of England, Wales, and Northern Ireland (Scotland currently benefits from a system similar to NUAR, known as VAULT). This means that it can be used as part of safe digging practices by eligible users as per HSG47, without a restriction on the number of eligible users (including contractors).

Responsibility for deciding on how, when, and if NUAR is used for these purposes remains with those carrying out excavations. By the end of 2025 NUAR will be operational.

There are estimated to be four million kilometres of pipes and cables buried underground across the UK. A hole is dug every seven seconds to install, fix, and maintain these assets that are critical in keeping the water running, gas and electricity flowing, and our communications with the outside world connected. There are believed to be around 60,000 accidental strikes on these pipes and cables every year – putting workers’ safety and lives at risk, as well as causing disruption to the public and businesses.

Each of the 600+ asset owners across the public and private sectors (including energy, water, and telco companies) hold data about their own assets, which they are required by law to share for the purposes of ‘safe digging’ (i.e. installing, maintaining, operating, and repairing buried assets). However, there is currently no standardised method to do this with multiple organisations having to be contacted for each dig, providing information in varied formats, scales, quality, and on different timelines resulting in a complex process for sourcing and using this information.

Due to the significant commercial and security barriers required to develop a platform like NUAR, there is no commercially viable service in the UK which brings together public and private underground infrastructure data in a single digital resource.

The fundamental purpose of NUAR is to accelerate the data-sharing process from, on average, six days down to 60 seconds, promoting more efficient management and maintenance of underground assets. It will also reduce the risk of potentially lethal utility asset strikes and will lead to enhanced communication between parties and improved data quality.

Accidental strikes put workers’ safety and lives at risk, and cause disruption to the public and businesses – costing the UK economy £2.4 billion a year. The economic benefits of NUAR are estimated to be over £400m per year. This consists of benefits in efficiencies, reduced asset strikes (and improved worker safety), and reduced delays to the public and businesses.

NUAR intends to provide a comprehensive, interactive, standardised, and immediate view of buried assets. This will be available via a secure, auditable, and trusted platform, initially to asset owners and their supply chain. This means:

• Owners of underground assets will have a single, reliable platform for sharing data, rather than having to share the same data multiple times through different channels. This will result in efficiencies in how data is shared.
• Planners will have immediate access to a more comprehensive and interactive view of underground utility assets, including assets owned by local authorities; rather than having to patch together a picture using data received in various scales, formats, and degrees of quality. This will result in efficiencies for how excavation works are planned.
• Workers in the field will have access to a more comprehensive and rich view of buried assets. This will help them make more informed decisions on how to carry out works safely and efficiently.
• Data owners will receive regular feedback on their data, both from a standards perspective and from excavators in the field. This will lead to the incremental improvement of data quality over time.

For asset owners there are the following three stages to getting your data into NUAR:

Stage 1: Engagement & Onboarding to send data to NUAR and agree legal framework, which includes:

• Identifying your organisation’s Data Lead.
• Attending a Data Workshop to assist you with this stage.
• Sharing your data with OS.
• Signing your Data Distribution Agreement (DDA) to enable your shared data to be published.

Stage 2: Transformation & Ingestion to agree Data Ingestion Specification (DIS) and be refresh ready, which includes: 

• Your data to be transformed to the NUAR Harmonised Data Model.
• Ordnance Survey will write and agree the DIS with you, enabling refreshed data to flow into the platform.

Stage 3: Using the NUAR Platform, which includes:

• Your data is loaded into the platform with a sustainable data refresh in place.
• Your data is viewable in the platform.

For contractors, please contact us and advise which asset owner on whose behalf you are working. We will then assist the process of the asset owner inviting you to the NUAR platform. Once you have received, completed, and submitted the registration form, your designated administrator will be given access and can invite and manage your companies users. Your asset owner can then link a job to you, enabling you to access the specified data.

The GDS Geospatial team, previously known as the Geospatial Commission, worked alongside asset owners and other stakeholders from 2019 to 2025 to develop the NUAR service, security measures, data model and legal frameworks, and were ably supported by a supply chain of world leading experts in their fields. The GDS Geospatial team appointed AtkinsRéalis to lead the development and build of NUAR, working with Ordnance Survey, 1Spatial, GeoPlace and the Greater London Authority.

In the move from build to operational phase in 2025, GDS appointed Ordnance Survey as the operator of the NUAR service, responsible for the day-to-day running. This includes maintaining the database and ensuring its security, operating the user interface and providing an account management service.

The government will continue to play a prominent role in NUAR: 

• The Secretary of State for Science, Innovation and Technology will retain the accountability for maintaining the register. 
• The GDS Geospatial team will retain policy oversight for NUAR, such as holding Ordnance Survey to account on the operation of the service and will progress legislation as required. 
• The GDS Geospatial team, working in collaboration with the National Archives, will also establishing how NUAR data will be licensed, in order to ensure that NUAR is strategically placed to deliver the maximum benefits to the nation.  

NUAR is a new and comprehensive register of asset data, here to complement and enhance existing practises. By providing a single authoritative source of data of underground pipes and cables in England, Wales, and Northern Ireland in a single online map, NUAR can dramatically streamline the ability for authorised users to enable safer and more efficient street works.

This supports Safe Excavation procedures and the avoidance of utility strikes when undertaking statutory duties in respect to the design, construction, maintenance, operation, or improvement of underground assets under any relevant legislation, including sections 79-82 of the New Roads and Street Works Act 91 and equivalent provisions in The Street Works (Northern Ireland) Order 1995.

The NUAR platform does not provide formal Health and Safety instructions or risk assessment advice. Users should be aware of all applicable guidance, including but not limited to: HSE guidance document HSG47; HSE guidance document GS6 (for overhead lines); and any specific direction given by owners of buried utilities.

Users should maintain existing Safe Excavation practices as specified in industry guidance and company policies, including for excavation near high-risk assets (e.g. where custom guidance or further engagement such as a detailed risk assessment or onsite supervision are required) and additionally to follow all instructions for necessary asset owner engagement, where flagged on the NUAR platform. This is to reduce the risk of harm to workers and damage to underground assets.

PSGA members who are statutory undertakers or own underground assets can access NUAR for the purposes of ‘safe dig’, subject to completing the necessary onboarding processes. PSGA members will not automatically be given access, and NUAR data will not be considered in scope for data sharing within the wider public task of Ordnance Survey.

The Office of the Scottish Roadworks Commissioner operates the Scottish Community Apparatus Data Vault (or Vault for short) which makes information about all underground pipes and cables in Scotland available from one centralised location. NUAR deployment is therefore only for England, Wales and Northern Ireland, which together with Vault, has resulted in the entirety of the UK being covered by a service of this kind. 

GDS are currently working with Scottish Roadworks Commissioner as part of the NUAR enhancements testing phase to test making NUAR data available for safe digging via Scottish Roadworks Register, which houses Scotland’s own National infrastructure map (Vault).