Investors are trying to beat a tax increase on buy-to-let properties in Britain, helping to push up house prices last month, a survey showed on Thursday. The Royal Institution of Chartered Surveyors (RICS) said its monthly house price balance rose to +50 from +49 in November, in line with a Reuters poll of economists. Overall demand for new properties rose to a three-month high after the announcement that a higher rate of real estate purchase tax would be introduced in April for investors seeking to buy properties in order to rent them out. Simon Rubinsohn, RICS’s chief economist, said a further heating up of the housing market was likely before April and the survey’s measure of house price expectations hit its highest level since April 2014. In a bid to cool down strong growth in the sector, British finance minister George Osborne announced in November that buy-to-let (BTL) investors will have to pay a 3 percentage point higher rate of stamp duty than residential buyers from April. BTL investors accounted for almost one in four house purchases funded by a mortgage last year, a chunk of the market unseen in other big economies. Overall, there are nearly 2 million private landlords in Britain, owning almost 20 per cent of homes. As well as the planned tax increase, the Bank of England is seeking power to curb lending to the BTL sector. RICS said prices in the housing market as a whole continued to be driven by a shortage of properties on the market but new instructions to sell homes rose for the first time since January 2015.