Gross mortgage lending hit £4.2bn in the first quarter of 2013, considerably up on the £3.7bn recorded in the same period last year.
The CML added that this total was split roughly equal between remortgages and house purchase.
Buy-to-let lending accounted for 13.4% of total outstanding mortgage lending in March and has steadily risen over the past year from 12.9% in 2012.
The industry body reported that there are now 1.46m buy-to-let mortgages in the UK, representing around 13% of all mortgages.
CML director-general Paul Smee said: “The buy-to-let mortgage market is performing well, against a backdrop of robust landlord – and tenant – demand for good quality rental property.
“As the private rented sector looks likely to be the longer-term tenure in which more households may live in the future, lenders are actively looking at how they can best evolve their future lending for those landlords who may wish to offer longer-term tenancies to their tenants – although concrete landlord demand for such borrowing is not yet clear.”
Kristjan Byfield, director at Base Property Specialists, said: “The rise of the long-term tenant is making the market much more stable for landlords.
“Tenants no longer look at a property as a place to live for six to twelve months but are looking for places where they can live for a few years or more. Because of this they are a lot pickier and so landlords need to stand out.
“Some landlords continue to try their luck on rents but most are aware that while demand is strong, the lack of wage growth means they need to be realistic about what they can charge tenants.
“If landlords charge too much, in a market as competitive as this they will be rewarded with a void period.”
