Permission in Flood Zone B is more achievable than in Zone A, particularly for less vulnerable uses, but housing still generally requires the Justification Test and a site-specific flood risk assessment. The outcome depends on the development plan zoning, the modelled flood levels and the design response.
Zone B is a moderate probability zone, so the sequential approach still applies: the planning authority will ask whether the development could reasonably be located in Zone C instead. Where it cannot, and where the site is appropriately zoned, a well-evidenced application can succeed.
The technical work matters. A flood risk assessment should establish design flood levels including an allowance for climate change, set finished floor levels with freeboard above them, demonstrate safe access, and show that floodplain storage and flow paths are not adversely affected.