An example Garden Centre in the Green Belt St Albans which could now be redeveloped for housing
Most Garden Centre sites are no longer horticulture, as the predominant purpose of the site is no sales, so they generally are sui gneric retail – large open areas (lack of roofs) typically exclude them from A1 according to caselaw. So they count as previously developed land.
In the Green Belt therefore if you wished to develop then you had to keep much the same footprint of buildings, there or there about – lots of cases see here.
The NPPF changes currently being consulted on in removing the openess impact test would allow the whole of such sites to be developed no matter how little they were covered in buildings, and discounting the limited impact on openness of all glass buildings.
Now dont get me wrong some garden centres are good locations for housing, even in the Green Belt. Take for example the ugly mass of Garden Centre tat around Crews Hill Station north of Enfield. But in other cases Garden Centres occupy strategic locations which are essential in securing the openness of Green Belts. Consider for examplwe some of the enormous garden centres around St Albans, rejected in favour of land at the edge of Hemel Hempsted.
This is likley to open up a hug loophole on these sites, disregarding the visual impact for a purely semantic test of where the land use ends, and will certainty add to the value of garden centres owners substantially without them lifting a finger.