A study model of the tested layout, not a proposed scheme. The framework fixed 2.66 hectares of developable land out of 5.22, so every home had to be found inside half the site.
The full story
A housebuilder was weighing a residential allocation on the southern edge of Balsall Common: land at Frog Lane, carried in the Solihull Local Plan Review as BC2, with an outline application in the pipeline for up to a hundred and ten homes. The headline number was attractive. The question an acquisition actually turns on is narrower, and nobody had answered it.
We were appointed to answer it, and to answer it quickly. The instruction was a plot-substitution appraisal: take the promoter's parameter and framework plans, substitute the client's own standard house-type range across the developable land, prove the affordable mix and the space standards, and issue a site plan and an accommodation schedule the land team could rely on. The outline application belonged to the site promoter and was still undecided; our work was for the housebuilder, and it was feasibility, not planning.
Every requirement pulled against the others inside an envelope the framework had already fixed: 2.66 hectares of developable land out of a 5.22-hectare site, with 1.37 hectares held for biodiversity, 0.81 hectares of public open space, retained veteran oaks, and the setting of two listed buildings just beyond the western edge. To reach a credible yield the standard footprints had to be worked hard without spilling into any of it.
The affordable requirement was forty per cent, split sixty-five rented and thirty-five intermediate, and it could not be met on unit count alone. Rented and intermediate homes each carry their own house-type and space-standard requirements, so the schedule had to satisfy the tenure split and the size standard together rather than one at the expense of the other. Where the requirement called for accessible, standard-compliant accommodation we introduced the compliant types instead of counting smaller ones.
This was also not a massing sketch. The layout had to be plotted in the client's actual house types, with their gardens, parking and turning, so the output could feed straight into the land and technical appraisal without being redrawn. Working directly with the client's design manager, we zoned the developable area and substituted the range across it: fifty-seven open-market homes from two to five bedrooms, and thirty-eight affordable.
The range was not a clean fit off the shelf. Early revisions exposed the gaps, including house types the standard library did not yet carry and a shift in the preferred market mix. A hand-marked change-of-mix instruction late in the process reconfigured the layout. We took the substitution through six revisions of the accommodation schedule inside three weeks, with a matching site plan each time, resolving the mix, the affordable percentage and the density on a consistent basis at every pass.
The answer was ninety-five homes: forty per cent affordable, 35.7 dwellings per hectare on the developable land. Not the hundred and ten an outline maximum implies, but a number a land appraisal can stand on, delivered before the decision was taken rather than after it. That is the entire value of the exercise, and it is worth having whichever way the decision then goes.
