The figures come after a string of lenders raised rates on new fixed-rate mortgage deals in recent days.
The increases were prompted by expectations of fewer and slower interest rate cuts by the Bank of England.
The Halifax is the latest lender to announce higher rates, with a plan to put up the cost of much of its mortgage range by 0.2 percentage points on Thursday.
The interest rate on a fixed mortgage does not change until the deal expires, usually after two or five years, and a new one is chosen to replace it. Doing nothing would leave people on a variable rate, which is very expensive.
About 1.6 million existing borrowers have relatively cheap fixed-rate deals expiring this year.
Mark Harris, chief executive of mortgage broker SPF Private Clients, said: ”There are likely to be ups and downs in mortgage pricing in the weeks and months ahead but ultimately borrowers will have to get used to paying more for their mortgages as the days of rock-bottom rates have long gone.”
This is the second consecutive monthly fall in UK house prices, according to Nationwide’s data. Every area has its own factors affecting house prices, so property values would have changed at varying rates in different parts of the country.
The figures are based on the building society’s own mortgage lending, which does not include buyers who purchase homes with cash, or buy-to-let deals. Cash buyers account for about a third of housing sales.
On an annual basis, the pace of house price growth slowed from 1.6% in March to 0.6% in April.