The Council of Mortgage Lenders (CML) said the figure was 7% up from June, and 15% higher than July last year.
Caroline Offord, a CML analyst, said that mortgage lending remained robust, despite regulatory changes earlier this year to toughen lending criteria.
There was a 25% rise in property transactions in the first half of 2014, the CML said.
However, Ms Offord said that affordability pressures could start to affect the property market.
"Economic conditions have strengthened, but while the Bank of England has signalled an improved economic outlook since May, headwinds remain," she said.
A rise in interest rates could hit the housing market, although any increase was likely to be "measured and gradual", she said.
New rule changes mean lenders must do more checks on borrowers' ability to repay loans, something that was blamed for slowing the number of loans and transactions earlier this year.
Net mortgage lending for the first six months of the year reached £10.5bn, which Ms Offord described as a "strong figure" compared to the past five years when the total barely exceeded £10bn for the whole 12 months.
"This is a sign of growth in the market and not just churn," she said.
The Office for National Statistics said on Tuesday that UK house prices had risen by 10.2% over the 12 months to June to hit a new record high of of £265,000. However, the London average was now almost £500,000.

As Mark Carney said, London is "effectively, the investment banker for Europe" and the City is the financial capital of the European Union.
Nearly 80% of foreign exchange trading and 30% of all bank lending in the EU flows through the UK.
How much that will change after Britain leaves the European Union is a matter of increasingly tense debate.
In the UK, very senior figures within the financial services sector argue that it is "nonsensical" to argue that after Brexit, large amounts of euro-denominated trading should move on to the continent.
They point out that significant amounts of dollar-trading are executed through London - and neither the EU nor the UK has a single-market agreement with the US.
Many on the continent of Europe see it differently, saying that financial oversight will only be possible if euro-trading valued in trillions of pounds a year is put under the direct jurisdiction of European Union-based regulators.
The biggest sector seen at risk is euro-denominated clearing, the billions of pounds worth of derivatives products traded every day to insure companies, for example, against interest rate changes, currency fluctuations and inflation risk.
Michel Sapin, the French finance minister, told the BBC that it was a question of control.
"I believe that there is an issue of sovereignty and security of European monetary markets and therefore the majority of the clearing houses cannot remain in London," he told me.
"There will be movement, there will be a displacement and actually many of the financial institutions are already preparing themselves towards that."
Many believe that if the trading moves, jobs will move as well.
"I don't see how it could be a good thing for the City," Mr Sapin said.
"The City will remain a large financial centre, will remain important for Europe as well as for the rest of the world.
"But the security of the monetary system is something that's of vital importance for any given country or any given groupings of countries - such as the case of the eurozone countries."
Hundreds of billions of pounds of trades will be at stake.
At the moment, the two sides - the UK and the EU - appear a long way apart.
Mortgage lending rose to £19.1bn in July to reach the highest monthly total since August 2008.
[NEXT_CONCEPT]
One of the most important sectors at the heart of the Brexit negotiations will be financial services.