Research by Paragon Mortgages, one of the leading buy-to-let mortgage lenders, has revealed an increase in landlords’ property portfolios in the second quarter of 2012.

During the past three months, the results of a survey show that portfolios increased from an average of 12.9 in Q1, to 14.1 properties in Q2. A year ago in Q2 2011 the average landlord portfolio size was 12.5 properties so the latest figures underline the typical growth in portfolio size.

One fifth (21%) of landlords who took part in the quarterly Private Rented Sector (PRS) Trends Survey, said that they were planning to add to their portfolios in the third quarter of this year, a figure which is up from 18% during the same time period last year.

Of those landlords who are planning to purchase buy-to-let property in Q3, 49% will be investing in terraced houses – which remain the most popular property type for landlords to invest in.

More than a quarter of landlords (26%) expect to buy flats or maisonettes, and 23% plan to purchase semi-detached houses.

John Heron, M.D. of Paragon Mortgages, said: “The fact that landlords are planning to make further investments in their property portfolios is positive news. It shows their appetite to grow their business to meet the on-going demands from tenants and demonstrates the viability of the UK’s PRS.

“The issues around housing supply in the UK are well documented and have been hotly debated over the past few months in particular. However, what our research shows is that landlords are investing further in PRS property and they look set to continue to buy over the coming quarters. Whilst this will not solve the problems around supply it will make a valuable contribution.”