Falls in Housing Construction

Detached, terrace, townhouse, garage, gazebo. The hazards are different from generic falls because workers interact with incomplete structures lacking permanent edge protection. Specific code, specific controls.

Quick Take

• Applies to NCC Class 1a / 1b / 10 buildings (houses, townhouses, ancillary). Maintenance/renovation is out of scope.
• Falls > 2 m = HRCW; SWMS required.
• Solid construction → passive prevention → work positioning → fall arrest → admin → ladders. Always in that order.
• Roof pitch: ≤ 26° with edge protection; > 26° add infill or catch platform; > 35° don't stand on it.
• Ladders only for low-risk, short-duration, single-handed work. 4:1 rule for setup.

1. Scope

• In scope: NCC Class 1a (detached houses), 1b (townhouses, terrace, boarding houses < 300 m²), Class 10 (garages, gazebos, carports). Up to 2 storeys.
• Out of scope: maintenance / renovation of existing housing, multi-storey > 2 storeys, dismantling/demolition (use [[demolition_work]] / [[managing_risk_of_falls]]).
• Why a separate code: housing-specific phases (truss erection on partial wall plates, prefab sequencing, scaffold-on-slab, fascia/eaves work) involve workers on incomplete structures.

2. Typical fall scenarios

![[falls_in_housing_construction_img001.jpg|520]] Figure 1 — Common fall scenarios in housing construction. Workers at upper-floor open edges, on truss top plates, off gable ends, through stairwells, off ladders.

3. Stages and their fall risks

Stage	Risk
Footings / slab	Falls into trenches, voids — covered by [[excavation_work]].
Floor laying (upper)	Open edges, voids; install edge protection before laying.
Wall frame erection	Workers on joist/plate level with no rails; risk of falls outward and into stairwells.
Roof truss erection	Critical phase; workers stand on internal top plates; falls through unbraced trusses; falls off gable. SWMS mandatory.
Roof batten fixing	Falls between trusses if spacing > 600 mm. Bottom chord becomes walking surface only when braced ≤ 3 m.
Roof covering (tiles/metal)	Pitched surface, fragile materials, gable edges.
Eaves, fascia, gutters	2–4 m external work; trestle scaffold / EWP / external platform.
Scaffold-on-slab	Internal platform for finishes; inspect, tag, assemble per spec.

4. The 2 m rule

WHS Reg 78: any work where a worker could fall more than 2 m triggers HRCW + SWMS. In housing construction this captures:

• Upper-floor activity, roof work, wall plates ≥ 2 m above ground.
• Scaffolds from slab to upper level (typically > 2 m).
• Exception: ground / 1st-floor ladder work below 2 m doesn't strictly need SWMS but still requires the hierarchy to be applied.

Reg 225: scaffold from which a fall > 4 m is possible — written competent-person inspection required before erection, and after every alteration / weather event.

5. Hierarchy applied to falls

Always work down. Ladders are last, not first.

1. Eliminate WAH — prefab at ground (truss assembly, frame assembly, panel cladding).
2. Solid construction / passive prevention — perimeter scaffold with rails; floor laid early; barriers around voids.
3. Work positioning (restraint) — harness + short lanyard preventing reach to the edge.
4. Fall arrest — harness, lanyard with shock absorber, anchor; with rescue plan.
5. Administrative — sequencing, no-go zones, supervision, permits.

6. Edge protection

![[falls_in_housing_construction_img002.jpg|520]] Figure 2 — Perimeter scaffold for housing: full-deck working platform, top rail, mid-rail, toeboard.

Specs

• Top rail 900–1100 mm above working surface.
• Mid-rail or infill mesh — gaps ≤ 275 mm.
• Toeboard ≥ 150 mm.
• For roofs > 10°: effective height measured 300 mm in from edge.
• Roofs > 26°: infill panels / mesh required + catch platform ≤ 500 mm below edge.

Designed for impact — posts must bend about their strong axis. ![[falls_in_housing_construction_img005.jpg|520]] Figure 3 — Timber guardrail post: bending about the strong axis (right) resists impact; weak-axis orientation (left) fails. Bolt + fishplate connections required.

Window/door openings in raised wall frames — protect before the frame goes up.

7. Ladders — narrow role only

![[falls_in_housing_construction_img006.jpg|520]] Figure 4 — Securing a ladder. 4:1 rule: base out 1 unit for every 4 units of height. Tie at top. Extends ≥ 1 m above stepping-off point. Non-slip feet.

Allowed for:

• Access / exit only.
• Short-duration, light, single-handed work (gutter clean, painting downpipes, minor electrical).

Not allowed:

• Tasks needing two hands (power tools, holding two-handed loads).
• Working from a ladder near unguarded edges/openings without additional PPE.
• Straddling, overreaching, work above shoulder.

Setup:

• Three points of contact at all times; 2 feet + 1 hand climbing; thigh on rung when working.
• Tool belt, not hand-carried tools.
• Single person.
• Slip-resistant footwear.
• No higher than: 900 mm below top (single/extension); 2nd tread from top (stepladder).

Prefer: EWPs, scissor lifts, mobile scaffolds, trestle scaffolds.

8. Mobile scaffolds and trestles

![[falls_in_housing_construction_img003.jpg|520]] Figure 5 — Mobile scaffold with internal access ladder. Castors locked before entry; never moved while occupied.

![[falls_in_housing_construction_img004.jpg|520]] Figure 6 — Trestle ladder scaffold with guardrailing and outriggers — light-duty external work only.

Trestle rules:

• Light/medium-duty only (paint, render, fascia).
• ≤ 2 m without guardrail; > 2 m needs top + mid + toeboard.
• Internal use only — not for external edges.

Mobile scaffolds:

• Castors locked before entry; never moved while occupied.
• Internal ladder access; tag inspections.

9. Roof work

![[falls_in_housing_construction_img007.jpg|520]] Figure 7 — Roof guardrail spec: 900 mm effective height (300 mm in from edge for pitch > 10°), gaps ≤ 275 mm, toeboard. Catch platform ≤ 500 mm below edge for pitch > 26°.

Pitch thresholds

• ≤ 10°: walk-able with edge protection.
• ≤ 26°: walk-able with edge protection. Wet/slippery may downgrade.
• > 26°: infill panels + catch platform ≤ 500 mm below; or work positioning.
• > 35°: don't stand. Use roof ladders, scaffold platform + work positioning.

Anchor points

• Purpose-designed roof anchors rated for the system (restraint vs arrest — different ratings).
• Timber roof anchorages are weak; fall-arrest needs ~6.5 m clearance — usually unavailable in housing. Restraint is preferred.

Harness types

• Restraint — short lanyard prevents reaching the edge. Preferred in housing.
• Fall arrest — only with verified clearance + energy absorber + rescue plan.

10. Scaffolds (housing-specific)

![[falls_in_housing_construction_img008.jpg|520]] Figure 8 — Timber scaffold (single-pole, high first lift) — standard housing rig with putlog-to-standard fixings and bracing. Detail in Appendix C of the source code.

Types in housing: prefab tube-and-coupler / modular; trestles; mobile (scissor / boom); single-pole bracket; engineered timber.

Inspection cadence

• Before first use (competent person; written record if fall > 4 m possible).
• After alteration, repair, weather event (storm, impact).
• At least every 30 days if fall > 4 m possible.
• Tag system: green (safe), yellow (defects, do not use), red (hazardous, isolate).

Working platform width by duty

Duty	Capacity / bay	Plank count
Light	≤ 225 kg	≥ 2 (≈ 450 mm)
Medium	≤ 450 kg	≥ 4 (≈ 900 mm)
Heavy	≤ 675 kg	≥ 5 (≈ 1000 mm)

Planks: uniform thickness; butt-jointed (not lapped); secured against uplift; overhang 150–250 mm beyond putlogs.

HRWL needed if fall > 4 m possible during erection: basic / intermediate / advanced scaffolding licence.

11. Voids and stair openings

• Cover immediately after flooring laid — plywood or proprietary covers, rated (≥ 2 kN / 200 kg point load), secured.
• Use guardrails (900 mm top, mid, toe) for openings used as access.
• Internal safety nets for stairwells during truss erection.
• Signage: "DANGER HOLE BENEATH"; danger tags on incomplete scaffolds.
• During risky phases: layered protection (net + guardrail).

12. Records

• SWMS for any > 2 m fall risk — hazards, hierarchy, roles, emergency, induction.
• Scaffold register — design, erection date, inspection tags, certifications.
• Harness / fall-arrest log — purchase, maintenance, last inspection. If used in a fall, retire it.
• Training records — white card, work-at-height, harness/restraint, scaffold (HRWL).
• Anchor certifications — rated capacity, install date, competent-person sign-off.

13. Common pitfalls / quick wins

Do

• Audit every project for SWMS at >2 m work — no SWMS, stop work.
• Brace trusses every 3 m; assemble first two before subsequent ones.
• Install void covers immediately after the floor is laid — before any wall/roof work.
• Use trestle scaffold for any > 30-min task at height; ladder only for ≤ 10-min access.
• Erect perimeter guardrailing before roof assembly.
• Tag every scaffold > 4 m fall potential; inspect monthly; photograph tags.
• For pitch > 26°: catch platform or work positioning. For > 35°: stay off the roof.

Don't

• Use a ladder as a primary work platform.
• Erect trusses without bracing on partial wall plates.
• Leave stair voids open after flooring.
• Add an extra lift to a manufacturer-rated scaffold without engineering.
• Run scaffold over or near unguarded edges.
• Use timber roof anchors for fall arrest without clearance verification.
• Re-use a harness after a fall — destroy it.

14. Cross-references

• Generic falls (other industries / multi-storey): [[managing_risk_of_falls]]
• See also: [[general_construction_work]], [[managing_risks_of_plant]] (Phase 3 — EWPs)
• Foundations: [[risk_management_process]], [[whs_consultation_cooperation_coordination]]
• Glossary: [[glossary_and_key_concepts]]

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Source: preventing-falls-in-housing-construction.md (Safe Work Australia, model Code of Practice, CC-BY-NC 4.0). Edition: October 2018. Last verified against SWA: 2026-04-27.