Prime London homeowners would need to cut the size of their homes by almost half to dodge the new £2m mansion tax, said Enness Global.
The research found sellers in prime central London with homes valued at £2m or more would have to make significant reductions to avoid the charge.
Enness Global analysed homes for sale in prime areas and found the average property listed above £2m is valued at £3.5m and covers 1,768 square feet.
With an average price of £1,995 per square foot, a home would need to be no more than 1,002 square feet to slip under the mansion tax threshold.
This means the average prime London property would need to shrink by 43% to avoid the tax.
Camden saw the biggest required drop in size, with owners needing to cut down by 48.8%.
In the City of London, the figure was 44.9%, while in Westminster, it stood at 44%.
Kensington and Chelsea properties would need to shrink by 42.7%.
Hammersmith and Fulham had the lowest reduction among prime areas, but homes would still need to be 33.6% smaller.
Islay Robinson, CEO at Enness Global, said: “Of course, we are unlikely to see prime central London’s property landscape carved up like a Christmas turkey simply so homeowners can avoid a mansion tax.
“However, what these figures highlight is the scale of adjustment a high net worth buyer would theoretically need to make to their lifestyle in order to escape this latest tax grab.
“Prime central London remains one of the world’s most desirable and resilient property markets and the reality is that those capable of purchasing at this level are unlikely to be phased by the introduction of a mansion tax.”
Robinson added: “What it does underline is the growing need for strategic planning around property ownership at the top end of the market, particularly for internationally mobile clients and long term wealth holders.”
