Soakaway Sizer: BRE 365 Design

Soakaway Sizer - The BRE 365 Calculation That Shows Its Working Planning conditions and Building Control ask for a soakaway designed to BRE Digest 365. The alternatives are a spreadsheet at your desk, a web calculator that charges per report, or a consultant at several hundred pounds per design. Soakaway Sizer runs the full BRE 365 method on your phone, offline, next to the trial pit, and shows the chain of reasoning behind every number so the design can be checked and defended. HOW IT WORKS Enter your percolation test results (pit dimensions and timed drop, or an infiltration rate you already have), the impermeable area draining to the soakaway, and the design rainfall. The app evaluates the 1-in-10-year storm across the full range of storm durations, takes the worst case as BRE 365 requires, and sizes the storage - showing every step, so you can check the working rather than trust a black box. WHAT IT CALCULATES - Soil infiltration rate f from your percolation test, with the lowest of your test runs governing the design - Warnings when the ground is likely unsuitable for infiltration - Required storage from the full storm-duration sweep, with the governing duration identified, not a single guessed storm - Optional climate change uplift on design rainfall, as many local planning authorities now require - Storage provided by crate/modular and rubble-filled constructions, using the appropriate void ratio, with manufacturer override - Works both ways: enter dimensions and check compliance, or enter your site constraints and get suggested sizes COMPLIANCE, LINE BY LINE Clear pass/fail lines for the checks an inspector looks for: half drain-down within 24 hours, minimum 5 m from buildings and 2.5 m from boundaries per Approved Document H, and prompts for made ground and groundwater. WHO IT IS FOR Groundworkers, drainage contractors, self-builders and builders dealing with planning conditions, percolation tests and Building Control submissions - and anyone who wants to see the method, not just the answer. A DESIGN AID, NOT A DESIGNER Soakaway Sizer is a calculation aid. It does not replace the judgement of a competent person, and every design should be verified by one before construction. Calculations follow the method of BRE Digest 365 (2016); the app is not certified, approved or endorsed by BRE. PRIVACY No sign-in, no ads, no tracking. Works fully offline. Your data stays on your device.