The global financial crisis will have a negative impact on South Africa's ability to deliver houses, the housing department said on Monday.

Head of the Gauteng department of housing Benedicta Monama said the economic slowdown would prevent the department from rolling out as many houses as it would like to.

"If the budget is larger, we can deliver more houses... but with the economy slowing down budgets will shrink," she said at the Grand Central Airport in Midrand, ahead of a helicopter flyover of various housing developments in the Gauteng province.

Monama said the increase in the price of building materials such as steel, had an impact on housing delivery.

"That is also how it impacts inflation in building material costs," she said.

The flyover, organised by the department of housing, will highlight progress on housing projects aimed at eradicating informal settlements and building integrated, mixed housing developments in line with the department's Breaking New Ground programme, launched in 2004.