The BT-owned firm – which maintains the telephone cables, ducts, cabinets and exchanges around the country – is aiming to reach four million homes and businesses with full fibre by the end of March 2021.
Full fibre, also known as fibre-to-the-premises (FTTP), uses pure fibre optic cables to deliver internet connections directly to buildings, rather than via a cabinet.
Openreach Chief executive Clive Selley said the company is now building at “massive scale”, with the latest additions to its list of areas taking the total to more than 100 towns, cities and boroughs.
“Every 28 seconds, we pass a home or business with our new future-proofed full-fibre network,” he explained.
“This has given us ever greater confidence in the level and accuracy of whatever we announce – which is why we’ve now laid out our build plans right up to the target delivery date of four million premises by March 2021.
“We also want to ensure we give our stakeholders – like council leaders, planners and MPs – the best view of where and when we intend to build so we can work together to build as rapidly as possible and help encourage people to take up the technology when it arrives.”
Northampton, Swindon, Watford and Derby have also been added to the tally, where work is set to begin over the next 18 months.
The move will come as good news to the Prime Minister, who wants full-fibre connections available across the country “for all by 2025”.
However, the UK’s telecoms sector has told Boris Johnson that his target will be a considerable task and will require a “pioneering spirit”.
In an open letter sent to Mr Johnson in August, the industry warned that planning reforms were needed to ensure all new-build homes are developed with fibre connectivity, as well as investment in digital and engineering skills to meet the challenge of a national roll-out.
It also called for a reform of the so-called fibre tax, which means fibre cables are taxed as if they were business buildings, and the implementation of plans to allow telecoms providers access to land where landlords are unresponsive.
Virgin Media, Openreach’s biggest competitor, has pledged to make its own hyperfast gigabit speeds available to almost 15 million homes across its entire network by 2021.
The service went live to 100,000 premises in Southampton on Monday.