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Minimum base sizes
Lean to greenhouse, 2ft projection

We recommend that your base should be no smaller than the minimum base size listed below and no more than a few inches larger.
The first dimension listed is the external projection (A) and the second dimension is the external length (B). The projection is measured from the existing building.
2'2" x 8'4" GREENHOUSE = minimum base size 667mm projection x 2530mm long (2'2" x 8'4")