Guidance only. Check before you act. Results are planning estimates, not a final drainage design, site survey or approval. Check current regulator, Building Control, planning, site and manufacturer requirements before buying equipment or starting work. Full disclaimer.

Terms & calculation disclaimer

The boundary between a useful planning estimate and an engineering design matters.

Last updated 3 September 2026

Planning information only

SepticSpec provides general information and planning calculations. It is not engineering advice, legal advice, a site survey, a permit, a Building Control approval, an environmental authorisation or a manufacturer's design.

No site verification

The website cannot verify groundwater, geology, flood risk, protected habitats, sewer proximity, neighbouring discharges, site gradients, access, property drainage layout or the accuracy of your inputs. Those factors can make a calculated option unsuitable.

Check before you buy or build

Regulations, regulator guidance and site conditions can change the correct solution. Before ordering a tank, treatment plant or drainage-field materials, or starting excavation, confirm the current requirements with the relevant environmental regulator, local planning authority / Building Control and a competent drainage designer or installer.

For England, Environment Agency guidance also makes clear that meeting the General Binding Rules does not remove the need for other permissions, including appropriate Building Regulations approval and planning permission where necessary. Approved Documents themselves are guidance on ways to meet the Building Regulations; they are not an approval of a particular property or design.

British Standards

References to British Standards are provided to explain the basis and context of commonly used design methods. SepticSpec does not reproduce or distribute the standards themselves. Users should obtain the applicable standard from an authorised source where required.

Liability

To the fullest extent permitted by law, use of the site and reliance on planning estimates is at the user's own risk. Nothing in these terms excludes liability that cannot lawfully be excluded.