UK Finance, the umbrella group representing major mortgage lenders, says there will have been a massive 83 per cent surge in buy to let lending by the end of 2021.
This will take the total borrowed by BTL investors in 2021 to £18 billion.
But this is dwarfed by the increase in house purchase mortgage borrowing - a total of £200 billion, up 53 per cent on last year.
However, remortgage activity was down slightly on last year, at £62 billion in 2021.
UK Finance forecasts that the total number of house purchase transactions, including cash purchases, will reach 1.5m this year - the highest for 14 years and 47 per cent above the 2020 level.
James Tatch, from the data and research team at UK Finance, says: “2021 has been a bumper year for mortgage lending amid the stamp duty holiday and homeworkers moving from cities.
“The outlook for the housing and mortgage markets over the next two years is for a return to more stable, balanced picture following the upheavals of the last two years.
“While risks remain, both to new lending and ongoing affordability, the market looks to be emerging from the pandemic in a better place than previously anticipated, supported by a much-improved wider economic outlook.”