Matthew Spry, a senior director at consultancy Lichfields, was speaking yesterday at Planning's conference in central London in a session on closing the gap between housing allocations, permissions and completions.
Spry said that Lichfields research had shown that larger sites deliver more homes per year than smaller sites, while greenfield sites deliver on average 40 per cent faster than the equivalent brownfield sites.
Other factors include sites containing more developers offering a greater range of housing products, which means a higher sales rate, he said.
The research also found that sites with higher levels of affordable housing delivered more units per year.
He added: "Although affordable housing is sometimes seen as a drain on the scheme, it actually does increase the rate of development."
Spry said this was due to the developer being able to sell on the affordable housing units quickly to housing associations.
But he warned that council housebuilding, though helpful, would not in itself deliver a step change in boosting delivery.
A number of authorities, including Birmingham City Council and the London Borough of Croydon, have set up their own companies or created programmes to build affordable homes.
RTPI research earlier this year found a sharp rise in councils directly building their own homes.
But Spry pointed out that the number of homes being built, even by large authorities, was always likely to be limited in scale.
Referring to Birmingham Council, claiming at the conference that it had built about 3,000 units over 10 years, he said: "[It's] by no means an insignificant number but in terms of Birmingham's housing challenge it's still quite modest in scale.
"These measures on their own won't sweep up housing delivery."
He also warned that faster delivery may not always mean better quality.
"Some of the schemes that are held up as examplars are actually built out incredibly slowly," he said.
"So Poundbury, a successful mixed-use urban extension, is built out at a glacial rate. It got permission in 1993 and is still only about two-thirds complete, a site of 2,000 homes. Are there trade-offs in terms of quality and the actual rate of development?"
He went on to say: "It's really important to get a better mix of housing on sites. Lots of local plans have policies to promote better mix of housing on sites."
He cited the National Planning Policy Framework's paragraph 61, which requires planning policies on the "size, type and tenure of housing" to reflect the needs of "different groups in the community", such as those needing affordable housing, students, older people and those who rent.
Spry concluded that while there was a gap between permissions and output it was "not a systemic problem".
Any potential solution to the issue of slow housing delivery "should be proportionate", he said, adding that there was a "broad consensus" that local plans were the right tools for authorities to speed up delivery.