Green Belt land next to Butterfly World in St Albans has been earmarked for up to 450 homes by consultants investigating potential areas for future development.

The 15-hectare site, near St Albans Polo Club and which includes Chiswell Green Farm, is one of nine areas identified for strategic development, contributing least towards the Green Belt.

An assessment of each site is outlined in the final report of an independent Green Belt review, completed for St Albans district council to guide its planning blueprint, the Strategic Local Plan.

Consultants Sinclair Knight Merz (SKM) said the parcel of land near Butterfly World helped prevent merging between Chiswell Green and St Albans but building upon it would not significantly compromise separation of the two settlements.

SKM recommended 60 per cent of the parcel be turned into houses, with the remainder supporting infrastructure such as roads and open space.

Depending on density, there could be between 270 and 450 homes built there should the consultants’ recommendations be adopted in the new strategic plan, which is still being written.

In Harpenden, two sites identified for potential release from the Green Belt include along Lower Luton Road in Batford and an area in the vicinity of Luton Road, Cooters End and Ambrose Lanes, near Spire Harpenden Hospital and The King’s School.

Up to 1,500 homes could be built across both areas.

East of St Albans, SKM has signalled that fields near Beaumont School, including Verulam School playing fields and land at Oaklands College, off Sandpit Lane, could support up to 1,650 homes.

Of the 55-hectare site, 33ha could be developed into homes while the remainder could provide education and health facilities, open space, roads and other infrastructure requirements.

SKM said building there would not reduce the gap between St Albans, Hatfield and Smallford.

But the consultants suggested that should the council release the land from the Green Belt, it should undertake a master planning exercise in consultation with the community and stakeholders.

And north of St Albans a 38-ha site has also been earmarked between Sandridgebury Lane and Woollams playing fields, for as many as 1,140 homes.

The village of London Colney could potentially yield 420 homes on a 14-ha area along Shenley Lane near the Napsbury Park development. However the land does not encompass the All Saints Pastoral Centre, which was sold to developers.

Meanwhile SKM has warned that the development capacity of areas mooted for housing east of Hemel Hempstead, including near Buncefield oil depot, could be constrained by underground oil pipelines.