Even in the face of mansion tax concerns, far from retreating developers are launching projects at an accelerated pace.
At least six ultra-luxury blocks have broken ground in 2025, while hundreds of prime properties are being expanded and refurbished into trophy homes, suggesting the market remains undeterred.
Wealthy Londoners’ willingness to undertake renovations that push their properties into the mansion tax Band A is particularly striking.
One notable example is the ‘corridor’ house in Knightsbridge, long a haunt of the global elite. This diminutive mews made headlines in 2017 after selling for over £800,000, despite being just three feet wide.
The new owners have undertaken an elaborate refurbishment including adding two new floors (one underground), doubtless at great cost.
The finished house, which retained its famous pink façade, will certainly be worth more than £2 million.
This demonstrates a clear appetite for property investment despite the tax implications.
Owners are accepting not only the immediate burden but also the uncertainty that future governments could increase the mansion tax threshold or rate.
It’s not just individual homes being done up. All across the city, enormous towers of ‘ultra luxury’ apartments are springing up, alongside some seriously expensive “trophy” developments.
Last year, the fifty-storey Opus tower on the Southbank neared completion offering studio apartments for nearly £1 million pounds and entry level three-beds for the thick end of £3 million.
It joins a cluster of Dubai-on-Thames style skyscrapers spread along the Thames which are designed to attract international investment from buyers for whom an additional £5,000 in annual property taxes is immaterial.
Yet even Opus, despite its high prices, represents the more accessible end of the ultra-luxury market. At Sixty Curzon Street in Mayfair, two-bedroom flats start at £9.6 million.
Residents are promised amenities and white-glove service to rival the Lanesborough, but the truth is that there may well be hardly any residents at all.
This ultra prime market exists for capital to change hands amongst the global super wealthy, who treat property as an asset class rather than homes.
Developments such as Sixty Curzon Street and the nearby One Hyde Park represent a world which is almost completely detached from global politics, current affairs, the economy, and of course, tax.
Individuals who are willing to pay £6,000 per square foot (the UK average is £300) for a property are unsurprisingly not worried about small increases in outgoings to maintain the flat.
Given that the service charges at Sixty Curzon and similar blocks run into the hundreds of thousands annually, a small tax surcharge is simply no big deal.
The capital’s capital appeal
London is almost completely unique in its ability to court the global elite. The city’s property market has delivered returns that outpace most traditional investments—but what sustains this appeal?
Climate plays a crucial role. What locals experience as grey and dreary is in fact a welcome respite from the blistering heat of the Gulf, whose glitterati have long summered here.
Travelling with large entourages, and often even their cars, these people find it easier to buy and maintain a London flat than to rely on the city’s hotels.
Beyond weather, the UK remains a very politically stable country – owing to its highly regarded legal, educational, and financial systems.
For the globally mobile wealthy seeking to benefit from these institutions, London provides a natural base. The capital offers a level of political connectivity and cultural infrastructure simply unavailable in most other cities.
Finally, London still holds cultural weight amongst high-net-worth individuals. A Belgravia townhouse sits alongside the Paris apartment, New York loft, and South of France villa as one of the ‘must have’ assets for the ultra-wealthy.
Given these fundamentals the idea that a ‘mansion tax’ could destablise the city’s luxury property market is misplaced. If anything, the clarity which has been uncovered with the government’s announcement has reduced uncertainty
For London’s ultra-prime segment, the outlook remains stable—and expensive.
And while mansion tax may not be changing the market’s direction, the foundation of any sound property investment remains the same — tailored advice from experienced lawyers who can ensure your assets are built on solid legal ground.
Duncan Bailey is a partner and head of the private client team at Brabners