ReFH 2 can be used to estimate greenfield, brownfield and post development runoff rates and volumes.

Latest research has shown that FEH methods that are implemented within ReFH 2 are more accurate than methods such as IH124 for conducting greenfield, brownfield and (simple) post development runoff calculations. ReFH 2 is the recommended method within the current CIRIA SuDS guidance for estimating peak runoff rates and volumes for greenfield, brownfield and (simple) post development scenarios.

Please see our Technical Guide which provides detailed instructions on how to estimate peak runoff rates and volumes for all three scenarios.