Facade retention and shoring: what a Sydney builder needs before demolition

Why facade retention needs an engineer, not just a demolisher

Retaining a heritage or streetscape facade while you gut and rebuild behind it removes the very structure that braced that wall — its floors, return walls and roof. The instant those are gone, the facade is a tall, slender, unbraced element carrying wind, its own weight and any out-of-plane eccentricity. The temporary support system has to do everything the building used to do, and it has to keep doing it through demolition, excavation, construction and reconnection — often 12 to 24 months. That is structural engineering and temporary works engineering, and it is the part a Sydney builder cannot afford to leave to assumption.

Metric Engineering designs the retention and shoring scheme, certifies its structural adequacy, and gives you the drawings and documentation councils, principal certifiers and SafeWork NSW expect.

The standards and regulations that govern the job

• AS 2601:2025 The demolition of structures — the current edition (it supersedes AS 2601‑2001) sets the requirements for planning and carrying out demolition, including protection of the public, adjoining property and retained elements such as facades.
• WHS Regulation 2017 (NSW), clause 291 — demolition of a load‑bearing element, and structural alteration or repair requiring temporary support to prevent collapse, are high risk construction work. A Safe Work Method Statement (SWMS) is mandatory before work starts.
• Demolition licence and notification (SafeWork NSW) — an unrestricted (DE1) or restricted (DE2) demolition licence is required for load‑bearing structures, and you must notify SafeWork NSW at least 5 days before demolition of a load‑bearing structure 6 m or more in height.
• AS/NZS 1170 (Structural design actions) — Part 0 (general principles/stability), Part 1 (permanent, imposed and other actions) and Part 2 (wind actions) govern the loads on the temporary retention frame. Wind on an unbraced facade is usually the critical case.
• AS 4100 (Steel structures) and AS 3600 (Concrete structures) — for designing and certifying the steel strongbacks, shores, props, walers and any concrete kentledge or footings.
• AS 3610 (Formwork) and AS/NZS 1576 (Scaffolding) — where the scheme uses propping, falsework or load‑bearing scaffold; AS 2601:2025 requires protective screens/scaffold to public boundaries to withstand impact.
• National Construction Code (NCC) — the permanent works behind the facade must meet NCC Volume One performance requirements; the temporary scheme must not compromise them.
• Environmental Planning and Assessment Act 1979 (NSW) — demolition is development. Consent conditions (and a Construction Certificate) routinely require a dilapidation report, party‑wall structural certification, and proof the works sit within your boundary.

What you need in hand before the first wall comes down

1. Development consent / CDC condition check — confirm what your council (City of Sydney, Inner West, Canada Bay and others all impose facade‑ and party‑wall conditions) actually requires.
2. Dilapidation (condition) survey of adjoining buildings, party walls, footpaths and council assets — taken before any site disturbance, so damage claims can be defended.
3. Engineered facade retention design — strongbacks, raking/flying shores, tie‑backs or a freestanding braced frame, with footings or kentledge, designed to AS/NZS 1170, AS 4100 and AS 3600.
4. Shoring and propping design for party walls and excavation — lateral support so the neighbour's wall does not rely on yours, certified independent under EP&A consent conditions.
5. A demolition sequence / methodology to AS 2601:2025 that keeps the facade braced at every stage — the order of removal is part of the design, not an afterthought.
6. SWMS and SafeWork NSW notification for the high risk construction work.
7. Structural certification of the temporary works for the principal certifier and council.

How Metric Engineering helps

We design and certify the full temporary works package — facade retention, raking and flying shores, back‑propping, party‑wall shoring, excavation support and the demolition methodology — and coordinate it with your permanent structure so the transition is clean. NSW‑based, NER-registered, certification included, fast turnaround. Send us the architectural set, survey and demolition scope and we will tell you what the retention scheme needs.

Frequently asked questions