Project Planning

How Long Does a Knock Down Rebuild Take in Castle Hill?

A realistic 2026 timeline for a Castle Hill knock down rebuild — from design and Hills Shire approvals through demolition to handover — and what causes delays.

TL;DR A Castle Hill knock down rebuild typically takes 12–20 months from first design meeting to handover. Roughly: 2–4 months for design and approvals (a well-prepared Hills Shire DA determines in about 8–14 weeks), 1–2 weeks for demolition, and 9–14 months for construction. The biggest swing factor is your approval pathway and how complete your application is. This article maps the full timeline and the local things that speed it up or slow it down. Stage 1: Design and documentation (1–3 months) Concept design, refinement, and full construction documentation. Custom designs take longer here than modified standard plans, but the time invested in complete, accurate drawings pays off at approval. Soil tests and surveys happen in this window too. Stage 2: Approvals (CDC weeks, or DA ~8–14 we…