Retaining Wall Submission in Singapore: Check URA’s 1.5 m Guidance

A retaining wall is treated as a structural element under the Building Control Regulations, so any wall beyond minor garden landscaping requires a building-plan submission to the Building and Construction Authority through a Qualified Person. Depending on height, site context and drainage impact, the project may also need Urban Redevelopment Authority clearance and Public Utilities Board sign-off. The first practical step is appointing a Qualified Person, and a QP(Geo) where geotechnical works are likely.

TL;DR:

URA favors walls under 1.5 meters where feasible; taller walls face planning review, while drainage changes, level changes, or nearby public sewers trigger PUB involvement.

BCA plans must show retaining walls, platform levels, and founding depth; omissions alone can prompt rejection, alongside missing calculations or site investigation records.

When planning clearance applies, secure URA permission before BCA review, but run site investigation and preliminary ERSS design in parallel with authority checks early.

For excavations exceeding 6 meters, BCA requires additional sheet pile controls, and the ERSS plan must specify monitoring and construction supervision.

After BCA approves the plan, obtain the permit to start structural works, submit the BEV_ERSS appendix, and finalize the site supervision plan before construction.

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AECTechnicalSG provides engineering consultancy and authority submission support for construction projects in Singapore, including structural and geotechnical engineering.

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Which approvals apply and when: BCA, URA and PUB triggers
Documents and technical reports your retaining wall submission needs
Step-by-step submission sequence and realistic timeline
PUB drainage and ECM checklist for retaining-wall projects
Geotechnical scrutiny and supervision for higher-risk ERSS works
How we approach retaining wall submissions in practice
Work with AECTechnicalSG on your retaining wall submission
FAQ
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Which approvals apply and when: BCA, URA and PUB triggers

Every retaining wall submission starts with the same question: which authorities actually need to see this project. BCA’s involvement is close to universal, since the Building Plan submission requirements list retaining walls among the structural elements a Qualified Person must show on plan. URA and PUB involvement depends on specific triggers tied to height, drainage and site context.

Here is how we triage a project before committing to a submission strategy:

Confirm wall height against planning norms: URA guidance favors walls under 1.5 meters where feasible, with taller walls subject to additional planning consideration.
Check whether the wall changes platform levels, drainage alignment or sits near a public sewer, which pulls PUB into the submission.
Verify lot boundaries and site access early, since these determine whether URA written permission precedes the BCA plan submission.
Flag any excavation depth or soil condition that signals a geotechnical risk requiring a QP(Geo) from the outset.

Resolving these triggers before drafting plans avoids a cycle of resubmissions later.

Documents and technical reports your retaining wall submission needs

A complete submission package goes well beyond a single wall drawing. The Building Control Regulations specify exact plan contents, and BCA’s structural guidelines add further requirements for earth-retaining works.

Site plan: boundaries, north point or georeference, lot numbers, distances to boundaries, existing and proposed platform levels and slopes, as required under the Building Control Regulations.
Retaining wall and ERSS plans: layout, sections, founding depth and minimum embedment, and details for struts, anchors or soil nails, following BCA’s Guidelines for ST Plan Applications, including advisory notes such as Advisory Note 1_09 on ERSS.
Site investigation report: BS5930-based format, AGS(SG) electronic file naming, borehole logs and laboratory records, per BCA’s SI report requirements.
Structural calculations endorsed by the Professional Engineer, with the QP(Geo) and an Accredited Checker signing off on ERSS content where the scheme calls for it.
PUB ECM drawings and report, named and formatted to PUB’s conventions, including cross and longitudinal sections when drainage is affected.

The Building Control Regulations explicitly require plans to show retaining walls, platform levels and founding depth as part of the statutory plan requirements, which means a retaining wall omitted from the site plan is grounds for rejection on its own. Our team’s guide to BCA regulations for residential retaining wall design walks through code-level considerations for smaller projects where this level of detail often gets overlooked.

Step-by-step submission sequence and realistic timeline

The sequence matters as much as the documents themselves, since authorities review in a fixed order and out-of-sequence submissions get bounced back.

Step 1: Appoint a QP, and a QP(Geo) if geotechnical works are expected, then scope and commission the site investigation.
Step 2: Secure URA permission first when height or site constraints trigger planning review, since BCA will not process a plan that lacks required prior clearances.
Step 3: Prepare ERSS and structural plans, the SI report, and PUB ECM documentation where drainage is affected, with QP and PE endorsements attached.
Step 4: Submit building plans to BCA through CORENET, noting that larger or more complex projects route through CORENET X while others use CORENET 2.0, and pay plan fees at first submission.
Step 5: After plan approval, apply for the BCA permit to start structural works, including the BEV_ERSS appendix, and finalize the site supervision plan before mobilizing.

Pro Tip: Run the site investigation and preliminary ERSS design in parallel with URA and PUB checks rather than waiting for each clearance in sequence, since this is the single biggest lever for shortening overall submission time.

Steps 1 and 2 can often run concurrently if the QP starts geotechnical scoping while URA review is pending, which is the main variable that separates a fast submission from a slow one.

PUB drainage and ECM checklist for retaining-wall projects

Any retaining wall that alters platform levels, redirects drainage or sits near a public sewer brings PUB into the submission, and following proper retaining wall drainage practices is essential since PUB’s documentation standards are specific enough that getting them wrong causes real delay.

Confirm whether the project changes platform levels, introduces new drains, or sits close enough to a public sewer to need PUB clearance.
Prepare the ECM report and ECM drawings using PUB’s own naming convention, typically formatted as “ECM Report – Location” and “ECM Drawings – Location.”
Include a colored site plan, spot levels, cross sections and longitudinal sections as PUB’s submission guidelines require.
Secure QECP endorsement where the works fall within PUB’s scope, and package the submission files to PUB’s required naming structure before e-submission.

PUB’s ECM guidelines are prescriptive about drawing naming, required sections and QECP endorsement, and following these conventions from the first draft avoids the back-and-forth that comes with a rejected first pass, as outlined in the ECM submission guidelines.

Geotechnical scrutiny and supervision for higher-risk ERSS works

Not every retaining wall carries the same geotechnical risk, and BCA’s review intensity scales with excavation depth, soil permeability and proximity to existing structures.

Deeper excavations and permeable soils require stronger mitigation measures in the ERSS plan, since ground loss around a sheet-pile wall can propagate quickly in loose or saturated ground.
BCA’s guidance on sheet-pile wall integrity sets mandatory measures to prevent gaps and contingency steps for when soil ingress is observed, with additional controls applying once excavation depth exceeds 6 meters.
Instrumentation such as inclinometers, piezometers and settlement markers should be specified along the ERSS alignment, with spacing tied to the risk profile of the specific stretch of wall.
Supervision responsibilities fall to the QP(D), the QP(S) and the builder, each with documentation obligations that continue through construction, not just at the design stage.

Our article on ERSS in deep excavations covers the geotechnical risk management side of this in more depth, and our page on the Qualified Person’s duties sets out exactly what the QP and QP(Geo) are each responsible for signing off.

How we approach retaining wall submissions in practice

We treat a retaining wall submission as one coordinated package rather than a single drawing handed to BCA. The structural and geotechnical review generally runs the URA check first, since a planning constraint discovered late can force a redesign after the SI report is already commissioned. From there, site investigation and preliminary structural design proceed concurrently, with PUB drainage checks folded in as soon as platform levels are known rather than tacked on at the end.

This sequencing is what keeps a submission moving instead of cycling through rejections. By the time plans reach CORENET, the ERSS scheme, structural calculations and PUB documentation are already aligned, with QP and PE endorsements attached where each authority expects them, and a supervision plan ready for the permit stage that follows.

— Aman

Work with AECTechnicalSG on your retaining wall submission

Retaining wall submissions move faster when one team owns the structural design, the geotechnical input and the authority coordination together, instead of three separate parties handing off documents between them. We offer this as a single engagement.

Structural and geotechnical engineering consultation services covering design, calculations and ERSS planning.
PE endorsement and authority submission support for BCA, URA and PUB documentation.
Shop drawing production and bar bending schedules once the structural design is approved.

If you have a retaining wall project in Singapore that needs a scope review and fee estimate, reach out through our services page and we will walk through the specific approvals your site requires.

FAQ

Do all retaining walls in Singapore need a BCA submission?

Most retaining walls that function as structural elements need a BCA building-plan submission through a Qualified Person, since the Building Control Regulations list retaining walls among required plan items. A small garden edging wall with no structural or drainage function may fall outside this requirement, but confirming with a QP is the safer first step.

When does a retaining wall project need URA involvement?

URA involvement generally depends on wall height and site context, with URA guidance favoring walls under 1.5 meters where feasible and additional planning consideration for taller walls. Checking this early avoids redesigning a wall after geotechnical work has already started.

What triggers a PUB submission for a retaining wall?

PUB clearance applies when the wall changes platform levels, affects drainage alignment or sits near a public sewer, following the PUB ECM submission guidelines. The ECM report and drawings follow PUB’s own naming and formatting conventions.

Who can sign off on a retaining wall submission?

A Qualified Person signs off on the structural plan submission to BCA, and a QP(Geo) is required when the works involve geotechnical design such as ERSS. Our page on Qualified Person duties explains the specific responsibilities each role carries.

What happens after BCA approves the retaining wall plan?

After plan approval, the project moves to the permit to start structural works, which includes BEV appendices such as BEV_ERSS and requires a site supervision plan before construction begins.