An ERSS plan submission is required whenever an excavation exceeds 1.5 meters (or 1 meter where the retaining structure is not reinforced concrete or steel), and it must go through BCA via CORENET or CORENET X. The immediate action for any Qualified Person facing this threshold is straightforward: commission a site investigation report, get it PE-certified, and file it in the correct format alongside the ERSS plan before submission.

TL;DR:

• ERSS plans are required for excavations over 1.5 meters, or 1 meter if the retaining structure isn’t reinforced concrete or steel, with thresholds decreasing for GBW and deeper excavations.
• Appointing the correct Qualified Person and Accredited Checker depends on excavation depth, with additional geotechnical specialists beyond 4 meters and further checks past 6 meters or when classified as GBW.
• Site investigation reports must be formatted as standalone PDFs with accompanying structured data files, accurate borehole coordinates, and full test results to avoid rejection delays.
• Submissions need precise signatures, proper document formatting, correct coordinate matching, and detailed contingency plans reflecting actual site risk, especially for deep or high-risk excavations.
• Using up-to-date BCA circulars, engaging early with reviewers, and considering external consultants like Aectechnicalsg can significantly reduce submission rejections and streamline approval.

Table of Contents

• ERSS Submission Requirements: When Does BCA Actually Require a Plan?
• Who Must Be Appointed, and What Each Party Certifies
• SI Report Format and Minimum Content BCA Expects
• What Goes Into the Technical Submission Package
• Choosing Between Deemed-to-Satisfy and Rigorous Assessment
• Forms, CORENET Workflow, and What Happens After Completion
• Why ERSS Submissions Get Rejected, and How to Avoid It
• How Aectechnicalsg Supports ERSS Submissions
• Treat Monitoring and Contingency Planning as Safety Deliverables
• Contact Aectechnicalsg for ERSS Submission Assistance
• BCA Guidelines and Circulars to Reference Before Submitting
• Sources
• FAQ

ERSS Submission Requirements: When Does BCA Actually Require a Plan?

Most delays on ERSS projects trace back to one avoidable mistake: assuming a shallow excavation is automatically exempt. It isn’t always. BCA’s structural plan submission framework sets excavation depth as the primary trigger, but the exceptions matter as much as the rule itself.

Plan approval is generally required once an excavation exceeds 1.5 meters. That threshold drops to 1 meter if the earth-retaining structure isn’t built from reinforced concrete or steel, which catches a surprising number of timber-shoring or sheet-and-strut arrangements that contractors assume fall under “minor works.” Beyond 4 meters, the project needs both a Qualified Person and an Accredited Checker involved. Past 6 meters, or where the works are classified as Ground-Related Building Works (GBW), you need QP(Geo) and AC(Geo) added to the team.

Not every excavation triggers this chain. BCA’s First Schedule exempts certain insignificant works from plan approval entirely, and localized pits treated as isolated, small-footprint excavations sometimes escape the full ERSS process, though QPs should never assume this without checking the specific area and depth cutoffs that apply to their site.

Utility trenches carry their own carve-outs. A narrow trench dug for a small-diameter pipe often doesn’t need an ERSS submission, but the exemption depends on pipe diameter and trench depth together, not either factor alone. Once trench depth crosses into the 1.5 meter to 2 meter band, or the pipe diameter pushes the excavation width past what a standard exemption covers, the project needs a proper ERSS submission regardless of how “routine” the trenching feels.

Here’s the part that trips up even experienced QPs: how you calculate depth when a site has multiple localized pits within one larger excavation footprint. BCA doesn’t let you assess each pit in isolation if they sit close enough together to interact geotechnically. The correct approach is to look at the overall excavation depth across the site, then apply the depth thresholds to that combined picture rather than to each individual pit.

A quick decision checklist for site visits and early scoping:

• Measure actual excavation depth first, not the design depth on paper. Site conditions and As-built levels sometimes differ.
• Confirm the retaining structure material. Non-RC/steel systems trigger the lower 1-meter threshold.
• Check whether adjacent pits should be combined for depth calculation purposes.
• Verify utility trench diameter and depth together against current exemption bands.
• Flag any depth beyond 4 meters immediately. That’s your signal to lock in QP and AC appointments before design work goes further.
• Flag depth beyond 6 meters or GBW classification as an automatic trigger for QP(Geo) and AC(Geo).

Pro Tip: Don’t wait until the design is finalized to check depth thresholds. Run the exceedance check during the feasibility stage, because retrofitting an AC(Geo) appointment into a project that’s already midway through design almost always costs more time than starting with the right team.

Who Must Be Appointed, and What Each Party Certifies

The appointment chain for ERSS work isn’t optional paperwork. It’s a legal structure defined under the Building Control Act, and BCA checks it against the depth and GBW classification of your specific excavation before it looks at anything else on the plan sheet.

For excavations up to 4 meters that don’t involve GBW conditions, a Qualified Person for structural works, QP(ST), typically carries the design and certification responsibility. Once depth crosses 4 meters, an Accredited Checker (AC) joins the process to independently review the QP’s design before submission. This isn’t a rubber stamp. The AC’s review covers the adequacy of the retaining system, the calculations behind it, and whether the proposed monitoring regime matches the risk profile of the site.

Past 6 meters, or when the works qualify as Ground-Related Building Works, the geotechnical specialists step in. QP(Geo) takes over the geotechnical design elements, including soil parameters, groundwater assumptions, and wall stability calculations. AC(Geo) then independently checks that geotechnical work, and their review scope under the Building Control Act regulations is specific: they assess SI adequacy, the geotechnical parameters used, the analysis methods applied, the instrumentation design, and how monitoring results get interpreted during construction.

What This Means for Your Appointment Chain
Depths beyond 6 meters or GBW-classified works require four distinct sign-offs on a single ERSS submission: QP(ST), QP(Geo), AC, and AC(Geo). Missing even one of these appointments is one of the fastest ways to get a submission bounced back before technical review even starts.

The certification forms expected on plan sheets follow a consistent pattern across submission tiers:

• QP(ST) certification appears on structural drawings and calculation sheets, typically as a signed and stamped endorsement on both the first and last sheet of the calculation set.
• QP(Geo) certification covers geotechnical design sheets and the interpretation of SI data feeding into the ERSS design.
• AC certification confirms independent structural review has been completed and documents any conditions or comments raised during checking.
• AC(Geo) certification confirms the geotechnical review, with particular attention to whether the SI data supports the design assumptions made.

One nuance worth flagging: AC(Geo) duties aren’t limited to a paper review. Under the regulatory framework, they’re expected to assess whether instrumentation placement and monitoring frequency actually match the risk the excavation poses, not just whether a monitoring plan exists on paper. A submission with a thin monitoring section, even from a well-qualified QP(Geo), tends to draw AC(Geo) queries that push the timeline back. Engaging your AC early, before the design is locked, tends to surface these gaps while they’re still cheap to fix.

SI Report Format and Minimum Content BCA Expects

Getting the site investigation report right on the first submission saves weeks. BCA’s guidelines on site investigation report requirements are specific enough that most rejections at this stage come from formatting errors, not from inadequate soil data.

1. Submit the SI report as a standalone PDF. File naming follows the convention SGO_SI_xxxx.pdf. Do not merge the SI report into the QP’s design report. BCA treats these as two distinct deliverables, and reviewers expect to find the SI data in its own file.

2. Attach a companion AGS(SG) file. This is a structured data format (.ags extension) that lets BCA and downstream engineers parse borehole and lab data programmatically rather than hunting through scanned tables. Both the PDF and the AGS(SG) file need to be submitted together.

3. Include borehole coordinates in SVY21, Singapore’s standard projected coordinate system, along with elevations referenced to Singapore Height Datum (SHD). Coordinates given to three decimal places materially reduce ambiguity when adjacent projects or utility corridors are involved.

4. Report termination depths for every borehole, along with the justification for why drilling stopped where it did, whether that’s refusal, target depth reached, or a specific geological marker.

5. Provide full field and laboratory test results, not summary tables alone. This includes standard penetration test (SPT) N-values, undrained shear strength data, and any specialized testing like vane shear or piezocone results relevant to the site’s soil profile.

6. Attach calibration certificates for testing equipment. Reviewers increasingly ask for these when unusual test values appear without supporting calibration evidence.

7. Reference recognized standards explicitly in the report, including BS5930 for site investigation practice and Eurocode 7 (EC7) principles for geotechnical design where relevant, alongside any applicable Singapore Accreditation Council (SAC) technical notes governing testing laboratories.

Annex A of the BCA guidelines lays out the minimum data items in table form, and it’s worth printing that table and checking it line by line before submission rather than relying on memory of what “usually” gets included.

Pro Tip: Present borehole data as clearly labeled tables with a simple plan showing borehole locations relative to the excavation footprint. Reviewers spend less time cross-referencing when the SVY21 coordinates on the plan match the coordinates in the AGS(SG) file exactly. Discrepancies here, even minor rounding differences, are a common source of query letters.

The SI report needs certification by the appropriate PE, generally the QP(Geo) on GBW-classified projects, confirming the data has been reviewed and is fit for the design purpose it’s being used for. A well-structured SI deliverable, with clean AGS(SG) formatting and clearly labeled borehole tables, tends to move through administrative screening noticeably faster than one assembled as an afterthought.

What Goes Into the Technical Submission Package

Beyond the SI report, BCA expects a coherent package covering drawings, calculations, monitoring provisions, and contingency planning. Each piece needs to demonstrate that the design accounts for real construction risk, not just theoretical soil mechanics.

Drawings and calculation sets follow a fairly standard structure across ERSS submissions: plan views showing the excavation footprint and retaining system, sections through critical points, and a calculation set demonstrating stability, structural adequacy, and deflection estimates. Endorsement placement matters more than most QPs expect. BCA reviewers look for PE signatures and stamps on both the first sheet of the calculation set and the last, treating both as bookends confirming the entire document has been reviewed as a whole rather than assembled from disconnected fragments.

The instrumentation plan is where many submissions fall short on technical merit even when the paperwork is otherwise clean. For high-risk sheet pile walls, particularly in reclaimed soils common across much of Singapore’s coastal development zones, instrument clusters combining inclinometers, piezometers, and settlement markers should be specified at spacing typically between thirty and forty meters, with additional instruments placed at every utility gap along the excavation perimeter.

Reporting frequency needs to scale with risk. A shallow excavation with stable soil conditions might justify weekly instrument readings. Deep excavations exceeding 6 meters, especially those near sensitive existing structures, typically warrant daily or even continuous monitoring during critical construction phases, tapering to a reduced frequency once the structure reaches a stable state.

The Depth Threshold That Changes Everything
Excavations exceeding 6 meters require construction supervision and explicit contingency measures written directly into the approved plans, not left to site discretion during construction. This includes pre-planned stop-work triggers and remedial action sequences for scenarios like sheet-pile gaps or water ingress.

Movement criteria need to distinguish clearly between an alert level, an action level, and a critical limit, sometimes called the “traffic light” system in practice, though BCA plans should spell out the actual numerical thresholds rather than relying on that shorthand alone. When monitoring data crosses the action level, the plan should specify what happens next: increased monitoring frequency, a site inspection by the QP or AC, and a documented decision on whether construction proceeds, pauses, or triggers remedial works.

Contingency wording deserves more attention than it typically gets. Vague statements like “appropriate remedial measures will be taken” don’t satisfy reviewers anymore. Specify what happens if a sheet-pile gap is detected: immediate notification protocol, temporary grouting or plugging method, and a defined inspection sequence before work resumes. For soil ingress or water gush-in scenarios, name the stop-work trigger explicitly, identify who has authority to call it, and describe the remedial sequence, whether that’s additional grouting, dewatering adjustments, or temporary bracing, in enough detail that a site supervisor unfamiliar with the design intent could still execute it correctly.

Choosing Between Deemed-to-Satisfy and Rigorous Assessment

BCA gives QPs two distinct paths for demonstrating that a GBW design is adequate, and picking the wrong one wastes both time and money.

The Deemed-to-Satisfy approach works from established design rules and conventional analysis methods that BCA has effectively pre-approved as adequate for standard conditions. Most straightforward excavations, reasonably uniform soil profiles, no unusually sensitive adjacent structures, and excavation geometry that fits within familiar parameters, can be justified this way without needing advanced numerical modeling. It’s faster to prepare and faster to review because reviewers are checking your work against known benchmarks rather than evaluating a bespoke analysis from scratch.

The Rigorous approach is performance-based and numerically driven. It typically involves Finite Element Method (FEM) modeling to predict ground movement, wall deflection, and the interaction between the retaining system and adjacent structures under specific, quantified performance criteria rather than relying on conventional rules of thumb.

Choose the Rigorous approach when any of these conditions apply:

• Existing adjacent structures sit close enough to the excavation that even modest ground movement could affect their structural integrity or serviceability.
• Groundwater conditions are complex or poorly understood, particularly where dewatering could trigger settlement in surrounding areas.
• The excavation geometry, depth, or soil profile falls outside the range that standard Deemed-to-Satisfy methods were calibrated for.
• A previous nearby project experienced ground movement issues, making regulators and neighboring stakeholders understandably cautious about a repeat.

Our geotechnical analysis guide walks through the practical steps for structuring an impact assessment under either approach, which is worth reviewing before committing design resources to a full FEM study that might not be necessary for your specific site conditions.

Forms, CORENET Workflow, and What Happens After Completion

The administrative path for ERSS submissions runs almost entirely through CORENET or CORENET X, and knowing which forms attach where saves real back-and-forth with reviewers.

1. Form BEV/A1 typically accompanies the initial structural plan application, establishing the basic project and applicant information BCA needs before technical review begins.

2. Form BEV/A2 or ACC documents the Accredited Checker’s certification where one is required, confirming independent review has taken place and recording any conditions attached to that review.

3. Form BEV/A3 and the associated ERSS annexes cover the specific technical content BCA expects, including ERSS_Annex A through E, which set out movement control limits and, notably, a monthly reporting obligation under Annex E for ongoing monitoring data.

4. Processing timelines differ meaningfully depending on whether an AC is involved. Structural plan applications without Accredited Checker certification are generally processed within 7 working days once documents are complete. Applications with AC certification take longer, typically 10 to 14 working days, reflecting the additional independent review step. CORENET X joint submissions, where multiple authority approvals are bundled, run on a longer window of up to 20 working days.

5. On project completion, record plans and C-forms come due. Form C1, C2, or C3, depending on the nature of the works, must be submitted along with as-built record plans. The QP responsible for supervision needs to submit their completion certificates within 14 days of ceasing supervisory duties.

Missing these completion deadlines isn’t a minor administrative lapse. Late or absent C-form submissions can hold up the statutory completion process for the entire project, which becomes a genuine problem when a developer is trying to obtain Temporary Occupation Permit sign-off on a tight schedule.

Why ERSS Submissions Get Rejected, and How to Avoid It

Practitioners consistently point to the same handful of issues causing resubmission cycles, and most of them have nothing to do with engineering complexity.

Administrative issues account for a disproportionate share of delays:

• Design certificates missing a signature or stamp on either the first or last sheet of the calculation set.
• SI files submitted in the wrong format, merged into the design report instead of standing alone, or missing the AGS(SG) companion file entirely.
• Coordinate errors, particularly SVY21 coordinates that don’t match between the SI report, the AGS(SG) data, and the plan drawings.
• Missing appendices that were referenced in the main submission but never actually attached.

Technical issues tend to be more consequential when they surface, because they signal a genuine design gap rather than a paperwork slip:

• Insufficient SI data density, boreholes spaced too far apart to reliably characterize soil variability across the excavation footprint.
• Instrumentation plans that exist on paper but don’t specify realistic spacing or reporting frequency matched to the actual risk level.
• Contingency measures written in vague, generic language that doesn’t tell a site team what to actually do if a trigger condition occurs.

The fix for most of this is procedural rather than technical. Run an internal pre-submission quality check against BCA’s own Annex A checklist before the package goes anywhere near CORENET. Bring your AC into the conversation while the design is still flexible rather than after it’s finalized, since early AC engagement measurably reduces iteration cycles compared to treating the AC as a late-stage gatekeeper.

Pro Tip: Keep a template library of contingency wording for common scenarios, sheet-pile gaps, groundwater ingress, unexpected obstructions, so your team isn’t drafting this language from scratch under deadline pressure on every project. Specific, pre-tested wording clears review faster than language improvised at the last minute.

How Aectechnicalsg Supports ERSS Submissions

Preparing an ERSS submission that clears BCA review on the first pass takes coordination across geotechnical design, PE certification, and CORENET administration, and most in-house teams don’t run this process often enough to keep every detail current.

Consultancies like Aectechnicalsg assist project developers and contractors with critical components for ERSS submissions, including PE endorsements for structural and geotechnical ERSS design elements requiring certified sign-off.

• Site investigation coordination, from scoping the borehole program through formatting the final SI report and AGS(SG) file for submission.
• Monitoring plan drafting that matches instrumentation spacing and reporting frequency to the actual risk profile of the excavation.
• CORENET and CORENET X filing assistance, including tracking which forms and annexes apply to a given submission tier.

Whether it makes sense to bring in outside support or manage the submission in-house usually comes down to how often your team handles ERSS work. A developer running one deep excavation project a year rarely has the standing familiarity with current BCA circulars that a specialist consultancy maintains day to day. Our PE endorsement and authority submission services page outlines the specific deliverables involved in that engagement model.

Treat Monitoring and Contingency Planning as Safety Deliverables

BCA’s review priorities have shifted noticeably toward risk-based outcomes rather than pure documentation completeness. A submission with clean paperwork but a thin monitoring section still draws scrutiny, because reviewers are increasingly asking whether the plan would actually protect the site if something went wrong during excavation, not just whether the required boxes are checked.

That shift rewards QPs who treat instrumentation spacing and contingency wording as core engineering decisions rather than boilerplate to fill in before submission. Getting your Accredited Checker involved while the monitoring plan is still being drafted, rather than after it’s finalized, tends to surface the gaps reviewers would otherwise flag. Aectechnicalsg’s work across geotechnical and structural submissions consistently shows that projects treating monitoring as a genuine safety deliverable move through BCA review with fewer queries.

— Aman

Contact Aectechnicalsg for ERSS Submission Assistance

Getting an ERSS plan through BCA on the first attempt takes more than technical competence. It takes current familiarity with formatting conventions, annex requirements, and the specific documentation standards reviewers check line by line.

Aectechnicalsg is the alternative to assembling an ERSS submission team project by project. We coordinate the structural and geotechnical engineering design, PE certification, SI report preparation, and CORENET filing under one engagement, so developers and contractors aren’t chasing separate consultants for each piece of a single submission package. That coordination is where most timeline slippage actually happens on ERSS projects, not in the engineering itself.

Our structural and geotechnical engineering consultation services cover the full range of ERSS-related work, from initial feasibility scoping through submission and post-approval monitoring support. If you’re preparing an excavation project and want a pre-submission review before filing, reach out through our services page to scope the engagement.

BCA Guidelines and Circulars to Reference Before Submitting

Every ERSS submission should be checked against the current versions of these documents before filing, since BCA updates circulars periodically and working from an outdated PDF is a common, avoidable cause of rejection.

• Structural plan submission guidelines, covering depth thresholds, appointment requirements, and processing timelines.
• Site investigation report requirements, governing SI format, naming conventions, and Annex A minimum content.
• Sheet pile wall integrity guideline, setting monitoring and contingency requirements for excavations beyond 6 meters.
• The Building Control Act and its regulations, which establish the legal basis for QP and AC appointment requirements.

Bookmark these rather than relying on secondhand summaries during plan preparation, since the exact wording of movement criteria and annex requirements matters when a reviewer is checking your submission line by line.

Sources

• Structural Plan submission | Building and Construction Authority
• Guidelines on requirements for site investigation reports
• Guideline on ensuring integrity of sheet pile wall to prevent ground loss

FAQ

What Are BCA’s Excavation Requirements for ERSS Plans?

Excavations exceeding 1.5 meters generally require ERSS plan approval, dropping to 1 meter where the retaining structure isn’t reinforced concrete or steel. Depths beyond 4 meters require QP and AC involvement, while depths beyond 6 meters or GBW-classified works require QP(Geo) and AC(Geo) as well.

What Permit Do I Need to Carry Out Structural Works?

Structural works, including ERSS installations, generally need a structural plan approval from BCA before construction begins, submitted through CORENET or CORENET X. The specific forms and certification required depend on excavation depth and whether an Accredited Checker is mandated for the project.

What Are the Requirements for an Accredited Checker Under the Building Control Act?

An Accredited Checker must independently review the QP’s design, covering structural adequacy, SI data sufficiency, and monitoring provisions, as set out under the Building Control Act regulations. AC involvement becomes mandatory for excavations beyond 4 meters, with AC(Geo) added for depths beyond 6 meters or GBW classification.

What Are BCA’s Piling Requirements?

Piling works generally fall under structural plan submission requirements similar to other earth-retaining or foundation systems, needing QP certification and, depending on scale and site conditions, AC review. Record plans and completion certificates, including the relevant C-form, must be submitted once piling works are complete.

Can Aectechnicalsg Help With an ERSS Submission That Was Already Rejected?

Yes. Reviewing a rejected submission against BCA’s Annex A checklist and current circulars often identifies the specific administrative or technical gap causing the query. Aectechnicalsg’s services page outlines the consultation options available for resubmission support.

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