By Jack Mendel UK house prices dropped by 0.4 per cent in April last month, as ‘affordability pressures’ including soaring mortgage costs deterred Brits from buying. Nationwide’s latest House Price Index showed that while the cost of a property fell month-on-month, the annual rate of change slowed too, to 0.6 per cent, from 1.6 per cent in March. The average price of a house in April was at £261,962, up from £261,142 in March in figures which are not seasonally adjusted. Average London house prices are typically double the UK average. Robert Gardner, Nationwide’s Chief Economist, said: “UK hou…