London flat and maisonettes have risen by 9.0% on last year to £442,304, according to Herddle analysis of government data.
The average price of all types of London properties has risen by 9.7% over the last despite the pandemic and the economic impact of Brexit.
This compares to inflation of just 0.8%.
Corey Cumins, chief executive of Herddle, said: “Investors and landlords who held their nerve AND held onto their flats have been rewarded with some remarkable performance. Prices of flats and maisonettes have risen by 9.0% and that’s way ahead of inflation.
“Looking ahead, it’s reasonable to expect more economic volatility – as both Brexit and new strains of COVID bite into companies, wages and jobs.
“We could see some house price volatility but that’s never a reason to sell assets – and we expect to see investors and landlords continue holding their nerve.”