Roof and edge protection plans for two-storey homes: layout decisions at set-up

On a two-storey house, the fall risk is rarely a mystery. Everyone on site knows the roof is up there and that the eaves are a long way down. What goes wrong is more mundane: the perimeter system is erected to a shape that does not match the finished building, the penetrations are cut after the plan was drawn, and the access point ends up under the material drop. Each of those is a layout decision, and each of them is cheaper to fix on paper than on the day the roof sheet is due.

The regulatory frame is deliberately general about this. Safe Work Australia’s guidance on working at heights sets out the hierarchy of control and the duty to manage the risk, but it does not tell you where to put a guard on a particular house. That is the builder’s job, and it is why the plan has to be specific to the block, the design and the trades who will actually be on the roof.

This article is about the physical layout decisions made at set-up. It is not a general falls guide and it is not a substitute for the safe work method statement that the job may require. It is the layer underneath: what goes where, and why.

Why the plan starts before the frame, not after the trusses

The edge protection layout is constrained by things that are fixed early: the boundary setback, the eaves overhang, the roof pitch, and the position of the set-downs. By the time the trusses are on, those constraints are locked in. A scaffold that needs a metre of clear ground at the base is a different proposition on a narrow infill lot than on a half-acre block, and the difference is visible from the day the slab is set out.

There is a commercial reason to think about this early as well. If the perimeter system cannot be erected as drawn, the scaffolder issues a variation, the roof sheet is delayed, and the delay lands on the critical path. Builders who resolve the layout at pre-start tend to find that the conversation with the scaffolder is about a system that fits, not about a problem that has to be solved on the morning of the lift.

The other early decision is the working platform. On a two-storey house, the crew may work from a platform at or near eaves height for the fascia and gutter, and from the roof surface itself for the sheet and the ridge. Those two working positions have different edge protection needs, and the plan should say which task is done from which position.

Height, pitch and the high-risk threshold

Not every roof task on a two-storey house is high-risk construction work, but some are. The distinction matters because high-risk construction work carries specific duties, including a safe work method statement prepared before the work starts. Height and pitch are the usual triggers, and the practical consequence is that the plan and the statement have to agree with each other.

A common failure is a safe work method statement written from a template that describes a different roof. If the statement says the crew will work from a perimeter scaffold and the site actually has a pitched roof with no platform, the document is not controlling anything. It is also the first thing a regulator will read after an incident. Our article on working alone on site covers the trigger side in more detail; the point here is that the layout has to match the method.

Pitch also changes the geometry of the guard. On a low-pitch roof, a perimeter guard at the eaves line can be effective for the whole working area. On a steeper roof, the working position moves up the slope and a guard at the eaves line may be too far below the person at risk to control the fall. That is a layout problem, and it is solved by choosing the right system, not by adding a warning sign.

Perimeter coverage: what the guard actually has to enclose

The perimeter of a roof is not a simple rectangle. On a two-storey house it usually includes a main roof, a lower roof over a rear extension or garage, a porch or entry canopy, and possibly a skillion link. Each of those has its own edge, and each edge has a fall on the other side of it. The plan should show the full perimeter of every roof plane that anyone will stand on, not just the outline of the building.

Where two roof planes meet at different heights, the lower plane is often used as a working surface for the upper one. That is a legitimate approach, but it means the lower plane needs its own edge protection, including along the line where it meets the wall of the upper storey. Builders sometimes treat the wall as a barrier; it is not, because the wall ends at the eaves and the fall continues past it.

Internal corners and returns are the other common gap. A guard that runs along the long sides but stops short of a return leaves an opening exactly where a person stepping backwards would find it. The layout should be continuous around the perimeter, with returns closed off or the opening guarded as a separate edge.

Penetrations, valleys and the edges nobody plans for

Most falls from a low-rise roof are not from the perimeter. They are from openings: a skylight, a flue, a vent, a solar conduit run, or a plant platform. These are the edges that get added to the drawing late, usually because the services were not coordinated before the roof was designed. By then the edge protection has been priced and erected to a perimeter that does not include them.

The plan should list every penetration and opening on the roof, with the control for each. A skylight that is going in later is still an opening when the roof is sheeted, and it needs a cover that is fixed down and marked, or a guard around it. A flue penetration is smaller, but it is still a hole a foot can go into, and it still needs a control.

Valleys and box gutters create a second problem: they concentrate the working position. A person cleaning or working in a valley is often standing below the general roof line, with the edge of the roof above them and the edge of the lower plane beside them. The layout should treat the valley as a working position and protect it accordingly, rather than assuming that the perimeter guard covers the whole roof.

Access, egress and the material path

Access is the part of the layout that gets the least attention and causes the most friction. The crew needs a way up and down that is separate from the path the material takes, because a person climbing a ladder while a sheet is being lifted past them is exposed to a struck-by risk that has nothing to do with the fall. On a two-storey house, the ladder or stair tower position should be set before the scaffold is erected, not adjusted afterwards.

The material path matters for the same reason. Roof sheets, battens and insulation are long, awkward and heavy, and the lifting point determines where the crew will be standing when they receive them. If the lifting point is at the ridge and the crew is at the eaves, the plan has to protect the eaves edge; if the lifting point is at the eaves, the crew may be working up the slope, which changes the fall geometry again.

Electrical safety interacts with this. Safe Work Australia’s guidance on electrical safety is relevant wherever the roof is near overhead lines or where solar work is planned, because the position of the access and the material path may need to change to maintain the clearances the network operator requires. If the roof is close to a service line, that is a layout constraint on the edge protection plan, not a separate issue.

Inspection, tagging and the handover between trades

Edge protection that is erected and then left alone is not edge protection. It is a structure that may have been altered, damaged or partially dismantled by the time the next trade arrives. The plan should include an inspection regime that is proportionate to the job: an inspection after erection, an inspection after any modification, and a periodic check while the system is in use.

Tagging is the practical mechanism for handing the system over between trades. A tag tells the next crew what the system is, when it was inspected and what it is rated for. Where a trade needs to remove a section to get material in, the plan should say who authorises that and how the section is reinstated before anyone works near the opening.

The handover problem is worst at the transition from frame to roof. The carpenters leave, the roofers arrive, and the edge protection may have been installed for the frame stage rather than the roof stage. If the plan does not anticipate that transition, the roofers will either work around a system that does not suit them or modify it themselves. Both outcomes are worse than planning the transition in advance.

Where the plan meets the rest of the site

Edge protection does not exist in isolation. On a residential site it sits alongside the general site safety arrangements: the traffic management, the temporary fencing, the amenities, and the arrangements for other trades working below. A roof edge protection plan that works in a vacuum can still fail because the ground below the edge is where the crew will land.

The safe work method statement is the document that ties these together, and a template is only a starting point. Our article on adapting a safe work method statement template for residential work in NSW deals with that side of the paperwork. The layout decisions described here are what the statement should be describing.

There are also site-specific hazards that the plan should acknowledge even if they are not the main subject. Asbestos is one: on a renovation or a knock-down rebuild, roof sheeting and eaves linings may contain asbestos, and the Asbestos and Silica Safety and Eradication Agency’s guidance on asbestos in the home is the reference for identifying and managing it. If asbestos is present, the edge protection plan has to account for the removal method, because the removal changes where people stand and how the roof is accessed. Pool safety is another example on sites where a pool is being built or retained; the NSW Government’s guidance on pools and pool safety sets out the barrier requirements that may affect how the rear of the house is accessed during the build.

Worked example: a two-storey infill in western Sydney

A builder in western Sydney is putting up a two-storey house on a narrow lot with a rear garage roof and a first-floor balcony over the entry. The design has a main pitched roof, a lower skillion over the rear extension, and a skylight over the stairwell. The scaffold is priced on the main roof perimeter only.

At pre-start, the builder walks the block and identifies three problems. First, the side setback is too tight for the scaffold base on one side, so the perimeter system has to be a cantilever or a different system on that elevation. Second, the skillion roof over the rear extension is at a height where a fall from it is still a serious risk, and it is not covered by the main roof scaffold. Third, the skylight is being installed after the roof is sheeted, so there will be an open penetration for a period.

The revised layout does three things. The tight elevation gets a system suited to the available ground, with the working platform set so the crew is not relying on the eaves line as a guard. The skillion roof gets its own edge protection, including along the line where it meets the first-floor wall. The skylight opening is covered with a fixed, marked cover for the period before the skylight goes in, and the cover is recorded on the plan so the roofer knows it is there and knows not to lift it for access.

The cost of doing this at pre-start is a conversation and a revised quote. The cost of discovering it on the morning of the roof lift is a delayed programme, a variation, and a crew working around a system that does not fit the building. That is the commercial case for treating the layout as a design decision.

What to put in the plan document

The plan does not need to be long. It needs to be specific. A workable version includes a marked-up roof plan showing every edge and every penetration, the control for each, the working platform positions and the access points, the inspection and tagging arrangements, and the handover triggers between trades.

It should also name the person responsible for each element and the point at which it is checked. On a small job that may be the site supervisor; on a larger one it may be a nominated person with the authority to stop work if the system is altered. What matters is that the responsibility is assigned before the work starts, not after something goes wrong.

Finally, the plan should be reviewed when the job changes. A variation that adds a dormer, moves a plant platform or changes the roof material can invalidate the layout. The review is cheap; the alternative is a system that no longer matches the building it was designed for.

Builders who want the broader CPD context for this kind of content can start at the PointCPD home page for NSW builder CPD courses, and the guide to how NSW builder CPD works explains how safety-focused learning fits the annual requirement. The course catalogue lists the current options.

Questions builders ask

• Falls Prevention
• Site Safety
• Working at heights

Published 26 June 2026. General information for builders, not legal, financial or engineering advice for a specific job. Check current requirements with the relevant regulator or standard before relying on them.