Define the permitted variation
List the size limits, post arrangements, roof systems, finishes and enclosure dependencies by family. Distinguish a valid made-to-measure selection from a request requiring engineering or commercial review. Free dimension entry without those rules is not sufficient evidence that every custom pergola can be supplied.
Connect dimensional choices to prices
Document the product and commercial rules that the proposed implementation needs to reproduce. Define quantity bases, thresholds and dependencies for your UK catalog and check the resulting quotations. A larger roof or opening can affect several components, not only an overall price field or the visual width of the model.
Validate the boundaries and outputs
Use the manufacturer's actual limits to test the smallest and largest permitted sizes, a value just beyond the range and an enclosure that conflicts with another choice. Check whether each case produces a valid specification or a clear review request. For a changed opening, reconcile its glass or screen quantities and corresponding quote lines. Include your required documents in the same check.
Implementation checklist
- Range-specific size limits
- Exception routing
- Dimensional quantities
- Boundary and document tests