Residential property prices are expected to rise 15 percent for the whole of 2018, according to Colliers International.
Jones Lang LaSalle puts the year-on-year increase at between 10 and 15 percent for the whole year compared to 2017.
JLL managing director Joseph Tsang said yesterday that should the police academy in Wong Chuk Hang be moved to the Greater Bay Area, 13,000 housing units could be built there.
He also said more nano flats will be built by developers after the government's introduction of a vacancy tax in order to offset higher costs.
The JLL's report found the average size of new flats has already decreased by about 40 percent over the past six years.
JLL expects home prices to climb another 7 percent in the second half - slowing down after an 8.6 percent growth rate in the first six months over the previous year.
Meanwhile, Colliers International research showed that total investment in all types of property hit HK$130.26 billion for the first half - the highest amount in Asia.
JLL said the total property investment volume soared 91.4 percent year on year in the first six months - the best first-half performance in a decade.
However, Colliers cautioned that price growth could slow down in the second half due to rising capital costs and continuous deleveraging in the mainland.
Vincent Cheung, deputy managing director of Colliers International Asia, said Hong Kong has an insufficient supply of subsidized housing, and called on the SAR to provide more affordable housing.
He proposed the ratio between private homes and subsidized housing should be three to seven.
"Hong Kong has a shortage of 582,880 units of subsidized housing, which would occupy around 270 hectares," he said.
JLL's Tsang doubts whether the vacancy tax will have a strong impact on cooling down the local property market, and said the government should instead focus on providing more brownfield sites to build more housing.
He said there are 760 hectares of smaller and scattered clusters of brownfield sites that can be used to boost land supply rather than relying on land reclamation.
"Using brownfield sites will be faster and more effective than land reclamation," Tsang said, adding that the land reclamation process would take at least 20 years.