This week, a public examination began its scrutiny of plans for 52,100 homes across Corby, East Northants, Kettering and Wellingborough to 2021.
But North Northamptonshire Joint Planning Unit manager Andrew Longley said the East Midlands regional spatial strategy (RSS) panel report next month may identify the need for 14,000 more homes.
"There has been pressure for the strategy to look beyond 2021. However, we want clarity and certainty to meet that initial growth," Longley told Planning.
"The RSS will help us move the strategy to 2026, but there will be a lot of work looking at infrastructure and further public consultation. We are not sure whether it will be a full-scale review or just an analysis of key elements," he added.
The extra homes would be built between 2021 and 2026. But the draft RSS signals that 28,000 homes should be considered between 2021 and 2031 as "an uncommitted planning assumption".
The core strategy argues that urban extensions west of Corby, east of Kettering and east and north-west of Wellingborough have the potential to accommodate growth beyond 2021.
Almost half the 52,100 homes must be built on greenfield land due to a shortfall in brownfield sites, it adds.
The strategy is available at PlanningResource.co.uk/doc.