Gutters, Downpipes and Overflow Calculator

A Beta testing version of a new Gutters, Downpipes and Overflow (GDO) Calculator is now available. It assists in developing a better understanding of the NCC Volume Two Part 3.5.2 Gutters and Downpipes Acceptable Construction Practice (ACP) provisions.

Enter information about the location, roof design and types of overflow measures. Based on the location, roof design and overflow types, the calculator provides the allowable gutter types, downpipe sizes and whether the selected overflow measures are adequate. It is a MS Excel file and uses data contained in NCC Volume Two for the calculations.

Practitioners are invited to provide feedback, suggestions and/or comments.

Please note that this version of the calculator has been developed to be compatible with MS Excel in Windows; please advise if a Mac or any other version of this content would be useful.

Image of GDO calculator

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