Britain is at risk of becoming a nation of green ghost towns

Leaky, inefficient buildings are a major problem in this country. MPs on the environmental audit committee have called for a national “war effort” on energy efficiency on the basis that “high energy performance standards” would “enhance energy security, reduce bills and cut emissions”.

Meanwhile, the Institute for Fiscal Studies estimates that a major programme to reduce energy use could cut aggregate household energy costs by £27bn in the first year. Though in both cases the research referred to domestic consumption, the same principles must apply to giant office blocks, where the heating or air conditioning is blasting out 24/7 and the lights left on even when its residents are tucked up at home in bed.

But as with all things net zero, the regulations are disproportionate and fail to take into account the practicalities of attempting to implement them. They go too far and too quickly without any real thought for how prohibitive the costs are or what the damage might be to the economy from buildings that are effectively rendered uninhabitable because their owners cannot afford the upgrade.

As part of its obsession with net zero targets, the Government intends to ratchet up the new Minimum Energy Efficient Standards for commercial properties quickly over time. A minimum rating of C will come into force by 2027, followed by B in 2030.

In London, only around 23pc of all offices are rated A+, A or B currently, and when the minimum E rating came into force it meant around 8pc of all commercial stock was effectively obsolete unless the owners of those buildings can afford the necessary retrofits, according to a study by French banking giant BNP Paribas. That’s the equivalent of 10,000 commercial spaces in London alone, it says.

Experts say upgrading a property to an energy efficient rating of E is relatively simple. Small changes such as motion-activated lights and better thermostat controls can soon get the building up to standard, but getting to a B is a different undertaking altogether.

Many buildings will require huge improvements ranging from rooftop solar panels on roofs, more windows, better ventilation and more insulation. Landlords are also being urged to consider replacing gas central heating systems with expensive, noisy heat pumps.

This leaves landlords with a choice: carry out expensive renovation work to bring buildings up to standard or cut your losses and try to sell properties that flout the new requirements.

Some are choosing to flatten existing structures and rebuild from scratch but as Marks & Spencer has discovered with its Oxford Street store, such proposals can also fall foul of green campaigners because of the carbon dioxide that is released during the process.

These rules put Canary Wharf squarely in the eye of the storm at a time when it is already bearing the brunt of the commercial property squeeze.

The departure of several high profile tenants including HSBC has left it battling vacancy levels of 20pc compared to 10pc for the City and 7pc for the West End, analysts at Jefferies estimated in September. That would be a three-decade high, the bank said.

The Canary Wharf group owns around 8m sq ft across its entire estate, and an estimated 6.9m sq ft across the whole district is thought to need upgrading. With estate agents Carter Jonas estimating that it will cost between £250 and £300 per square foot to lift a building’s rating from C to A, the bill to fall in line threatens to be extortionate.

Once a dazzling beacon to foreign investors like those that have graced Sunak’s summit, Canary Wharf risks becoming a monument to the worst of net zero madness.