"There isn't really one simple initiative that changes the way the housing market works.
"It's a very complicated beast so I wouldn't get expectations too high about changing the trajectory of house prices next week."
The commission focused on the need to free more land on city fringes for home-building, but Mr English said some of the best opportunities for development, particularly for low-priced housing, were within cities.
"The Government owns $15 billion worth of houses, and, in most cities, the best opportunities ... [are] on the government-owned Housing Corp land.
"We'd expect that the Government needs to make much better use of the very valuable asset that it owns in our cities, and we're in a process of policy and cultural change so that can happen in the next decade," he said.
Speaking on TVNZ's Breakfast, Mr Key said changing the Resource Management Act (RMA) to speed up the development of land will help solve the supply and demand issue.
"When you go for an RMA consent at the moment you've got to go through an arduous process over a long period time - in the end someone pays for that and that is the consumer.''
Mr Key said there was no silver bullet for solving housing affordability issues in New Zealand.
"We're not arguing that house prices will all of a sudden fall overnight as a result of what we're doing.''
Housing divide - English's plan to slow price boom
Under its Tamaki Transformation project Housing NZ is removing or renovating 156 of its houses in Glen Innes to make way for new or renovated state units and houses and about 140 privately-owned homes.
Other measures Mr English will announce today include moves to speed up the consent process for new homes and cut its cost.
The plan would require changes to the Resource Management Act and the Local Government Act.
Mr English and Auckland Mayor Len Brown downplayed the prospect of it being at odds with the Auckland Plan's drive for a "quality compact city", limiting urban sprawl.
Mr English said the Government planned to "get alongside councils" to work on the issue.
Mr Brown said: "As the minister says, this is a complex issue and any solution must include both greenfield and brownfield development."
But Labour's housing and local government spokeswoman Annette King said tension between central and local government over the plan was inevitable.
Tackling the high cost of home ownership
* Government will work with councils on urban planning to make it easier to build houses on "greenfield" sites outside city boundaries and on "brownfield" sites within cities.
* Further Tamaki Transformation-style redevelopments of state housing assets will be done.
* Changes will be made to the Local Government and Resource Management Act to make it easier, quicker and cheaper to build houses.
* Building costs will be reduced through work on the Building Act.