Many borrowers new to the buy-to-let sector are nonetheless determined that their property portfolio will be a long-term investment, according to a new survey. Three quarters of all new landlords say they will retain ownership of their existing range of houses for more than five years, the mortgage Trust's poll revealed, while more than one in four anticipate possessing theirs for over 15 years. Much of this confidence owes to the currently high rents found in Britain, which have risen by 6.9 per cent on average in the past three months, resulting in turn in higher yields for landlords. Buy-to-let borrowers hope to use the funds secured through initial letting to reinvest in property, the mortgage Trust also found, with landlords typically predicting that the size of their property portfolio will treble in this period.