Remortgaging loans approved in July hit the highest level for nearly seven years, the Bank of England data show.
Mortgage approvals for house purchases also rose to a 17-month high.
Both remain far below the peak of housing market activity, but signal an assumption of imminent rate rises despite market turmoil in recent days.
The economic situation in China created a shock across world markets and some analysts suggested this could delay a rise in the Bank rate in the UK.
The governor of the Bank of England was more circumspect in a recent speech and has hinted that a rate rise could be seen next year.
Homeowners have been increasingly signing up to mortgage deals, especially by remortgaging, in anticipation of a rate rise. This has been encouraged by competition between lenders battling over borrowers' custom.
Howard Archer, chief UK economist for IHS Global Insight, said the Bank's latest figures were "compelling evidence" that housing market activity was firming up.
"It is possible that July's performance may have been lifted by some house buyers looking to move quickly to try and lock in a low mortgage interest rate before they start rising," he added.

The city's Labour council unveiled the proposal as part of the city's new development plan.
The report said the new homes are needed to cope with a predicted increase in the city's population of 40,000 people by 2030.
A Lib Dem councillor described the figures as "unrealistic".
The document identifies 62 sites across the city that could be used for housing, including Holme Hill which could see 5,580 properties built and Clifton Gate which the report said has potential for 4,020 new homes.
Some of the proposed new homes would be built on greenbelt land.
Councillor James Alexander, Labour leader of City of York Council, said the biggest challenge facing the city was the need for affordable housing.
He said: "We've taken the tough decision to allocate 1.8% of draft greenbelt land for development in order to meet the needs of our rapidly growing city and deliver key developments such as York Central, and to deliver jobs, homes and protect York's unique built environment for future generations."
Councillor Ann Reid, Liberal Democrat spokesperson for planning and sustainability, claimed that the city's population had only grown at 1% per year over the last decade, a figure which only required 400 new homes each year.
She said the target of 1,090 new homes a year had been "plucked from nowhere".
Ms Reid said: "What we do know is that growth on this scale would radically alter the character of York and put a strain on existing infrastructure."
The plan is to be out to public consultation.

The neighbours entered the burning property in Milford Drive, on Sunday afternoon in an attempt to rescue two cats, police said. The occupants were not home at the time.
The women had inhaled smoke and were taken to hospital with breathing difficulties. The cats were unharmed.
Fire destroyed the front door and caused heavy smoke damage to the house.
Dorset Police said it believed the fire had been started deliberately through the cat flap in the front door of the property at about 15:00 BST.
Officers are appealing for witnesses or anyone with CCTV to get in touch.
Det Con Luke Davis said: "I am appealing to anyone who saw suspicious activity near to the property during that afternoon, particularly anyone seen in the garden or the front drive of the property just before 3pm, to please contact me.
"If you have any information about the cause or motive of the fire, please contact Dorset Police or call Crimestoppers anonymously."

Gary Price was suspended from all council duties for five months in November after Powys council's Standards Committee ruled he had breached the code of conduct.
His appeal has been dismissed by the Adjudication Panel for Wales following a two-day hearing in Llandrindod Wells.
Mr Price has been contacted for comment.
He was found to have sent information which the council said "incorrectly and unfairly" portrayed what happened at a grievance appeal hearing, in which he was a panel member.
The Adjudication Panel for Wales unanimously agreed to refer the matter back to the Standards Committee with a recommendation that Mr Price be suspended for three months.
Council leader Barry Thomas said the decision "sends out a clear message that those who enter public office have to operate within the members' code of conduct and maintain the highest possible standards".
Continued expectations of an interest rate rise are prompting more homeowners to lock into a new mortgage deal, figures suggest.
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Plans to build more than 1,000 homes a year in York over the next 15 years have been criticised  by opposition councillors.
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Two women have been rescued following a suspected arson attack on a house in Bournemouth.
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A decision to suspend a Powys county councillor has been upheld.