“Higher cost alone isn’t a reason” — turning SuDS compliance into a smarter value conversation

One line in Standard 1 is easy to overlook, but it has real commercial impact: when using a lesser priority final destination, “higher cost alone shall not be a reason” to utilise lower priority final destinations. For developers, that changes how value engineering should be handled.

Instead of treating rainwater harvesting as an optional upgrade, it’s often better to treat it as one of the baseline options to be assessed, alongside infiltration and other discharge routes. If you decide not to proceed, you’ll want evidence that you’ve still utilised higher priorities to the maximum extent practicable.

This doesn’t mean every site needs a large, complex system. It means the decision should be structured: confirm demand for non-potable water, confirm contributing catchment area, assess practicality and constraints, and document the outcome. That’s a more defensible position than “we didn’t include it because it costs more”.

Suppliers’ packaged systems and sizing tools can help teams quantify options quickly. GRAF UK, for example, provides complete packages across a range of tank sizes and a calculator to support early sizing discussions.