In the 1980s national policy required that a proportion of the 5 year requirement was small site.
Today the labour party is to resurrect this.
The government might reply this is unnecessary as the deliver ability requirement implies more small sites if large sites might take many years to deliver. This is certainly implied in several called in appeals such as in the recent batch in Cherwell.
What slightly concerns me about this is two things.
1) The best is the enemy of the good. It will take longer to adopt local plans as they must deal with call for sites and allocation of many more sites, and small sites are often disproportionately controversial.
2) It confuses correlation with causation. Other jurisdictions such as France and Canada, often deliver more homes, and more small sites, not because they specifically allocate more small sites, quite the opposite, they allocate more large sites which are then subdivided and sold off as small sites. They operate zoning and subdivision systems.
So I would rather we have a system which is evidence based. a focus on larger sites, except in very rural districts, and then splitting those sites up amongst multiple ownerships to deliver at a faster rate.