Andrews & Robertson raised £13.4m when 60% of its 91-lot, mixed catalogue sold at its New Connaught Rooms, WC2, auction on 22 July.
Post-sales lifted the success rate to 63% and the total to £14.1m.
Senior auctioneer Robin Cripp said: “Increasingly, we are seeing investors looking for stock they can add value to, and asset-sweat, that offers long-term security, or is sited in good locations where they can be more sure of price increases in the future.
“Properties that are not in one of these categories are harder to sell without realistic pricing.”
Notable sales included a four-bedroom, terrace house in Melody Road, SW18, which made £700,000 off a guide of £600,000.
Three interconnecting houses in Madeira Road, SW16, made £975,000 off a £900,000 guide price.
A commercial receivership in Queens Road, SE14, reserved at £300,000, sold for £445,000, and a part-vacant parade of shops producing £45,000 pa in Dartford, Kent, sold for £550,000 off a £350,000 guide, reflecting an 8% yield.
Long-term security fuelled demand for a portfolio of ground rents in Letchworth, Hertfordshire. They sold for £467,000 off a collective guide of £450,000.
