• 14 million customers to keep safe and warm
  • 15,500 square miles of territory to cover
  • 8,000 kilometres of pipeline to lay (think London to Las Vegas)
  • 800,000 service connections to install

Skanska is part of an eight-year £1.6 billion joint venture project for National Grid, replacing gas mains in London and the east of England, which began in 2013.

tRIIO® is a partnership between Skanska and Morrison Utility Services which will ensure the safety and reliability our gas mains pipework for years to come.

We provide a wide range of services to plan, schedule and undertake the works. Part of the process is keeping residents and the local community informed and updated with what is happening..

Gas supply

We provide design, engineering and delivery to improve gas distribution services to millions of people living and working in north London and the east of England.

Gas connections

Our job is to replace old gas mains, lay new ones, install new connections to houses, flats and commercial premises and help our clients with emergency response services. 

Mains replacement

We are working on a 30-year plan to replace old cast iron and ductile iron pipes with highly durable, non-corroding plastic pipes. These will provide homes and businesses with a safe, secure and reliable gas supply network for more than 80 years.

In addition, we ensure that existing and new customers are safely and securely connected to the network and have access to a reliable gas supply throughout the year.

We see this as vital to the long-term well-being of millions of people and we’re immensely proud to be doing it.


Service: Construction, Operations & Maintenance
Mark segment: Oil & gas, Underground/tunnels
Start date: 2013
Completion date: 2021
Clients: National Grid
Country: United Kingdom
City: London
Project status: Ongoing