Drainage and Slope Stability: What Hillside Sites Need to Get Right

Fil Engineers

Published on: 07/10/2026

A plain-language guide to drainage and slope stability on hillside sites in NZ, what the Building Act requires, and warning signs to watch for.

drainageslope stabilitygeotechnicalhillsidebuilding consent

Retaining Walls: When You Need an Engineer and When You Need Consent

Fil Engineers

Published on: 06/10/2026

A plain-language guide to when a NZ retaining wall needs a building consent, when it needs an engineer, and what keeps it standing.

retaining wallsbuilding consentgeotechnicalNZ building codefoundations

Fil Engineers

Published on: 04/10/2026

A plain-language guide to expansive clay soils in NZ, why they crack floors and walls, and how foundations are designed to cope.

expansive clayfoundationsgeotechnicalNZ building codecracking

Fil Engineers

Published on: 01/10/2026

A plain-language look at liquefaction, how it can affect your section, and why it matters for your foundation design.

liquefactionfoundationsgeotechnicalTC1 TC2 TC3NZ building code