How to Choose As-Built Surveys for Ontario Owners and Contractors

Choose an as-built survey by agreeing the accepting designer’s or authority’s requirements before requesting a quote: what needs measuring, what evidence is available and who takes responsibility for the drawings.

1. Define the record the recipient needs

Identify who will review the completed-work record and its intended use. Ask that recipient to confirm the quotation brief in writing.

The OAA/OGCA’s 2010 joint best-practice statement recommended agreeing detail, accuracy, copies, medium, software format and incorporated contractor information before contracting. Use it as a scoping checklist, not a current universal approval rule.[3]

• Coverage: identify the site, completed work and features to measure.
• Recipient and purpose: name the reviewer and intended use.
• Document: establish whether the recipient wants measured drawings, contractor as-builts or professionally verified record drawings.
• Accuracy and references: specify critical tolerances, coordinates, control and elevation datum.
• Evidence: list contractor records and change documents to incorporate.
• Outputs: specify file formats, software versions and copies.
• Responsibility: name who measures, prepares, reviews and signs, and who handles revisions.

Separate the recipient’s required scope from optional additional measurements or outputs so quotations cover the same work.

2. Separate measurements from concealed-work records

Request evidence labels beside relevant features, using these procurement categories:

• Field-measured: identify what was measured and the survey date.
• Contractor-supplied or record-derived: identify the source document, reference and date.
• Unverified or inaccessible: identify what could not be checked and why.

The OAA/OGCA statement assigns contractors responsibility for gathering construction field information, including concealed conditions.[3] PEO’s July 2018 terms of reference—not a completed practice guideline—identifies reinforcing steel, concealed beams and columns, buried foundations and underground infrastructure as potentially difficult, costly or impossible to verify after construction.[4]

Ask what supporting records exist and what additional investigation the accepting professional requires. Keep unresolved gaps visible beside the affected features rather than relying on a general limitation note.

3. Check advertised measurement and drafting capabilities

Use service pages to identify capabilities to confirm in the quotation, not to define the commission.

For staged measurement and drafting, Ontario Construction Surveying advertises as-built surveys and drawings at multiple construction stages, from a single detail to extensive project information. It says field information can transfer directly from surveyors to drafting staff, with CAD or PDF outputs ranging from simple sectional drawings to multilayered 3D drawings.[1] Ask whether its proposed scope covers the required completed features and design checks.

For site coverage and professional responsibility, AKM Surveying advertises service throughout the GTA and Ontario. Its stated scope includes building locations and footprints, finished grades and elevations, driveways, retaining walls, utilities and deviations from the original construction layout. AKM says every deliverable is reviewed for accuracy and signed by a Licensed Ontario Land Surveyor.[2]

Confirm how any advertised capability applies to the project. Ask what “utilities” coverage includes, what is observable and which information would come from records.

4. Specify accuracy, references and deviations

Ask the recipient to identify critical accuracy zones. The OAA/OGCA statement recognises contracts may call for greater accuracy in selected areas; it does not establish a universal tolerance.[3]

Agree survey control, coordinate reference, horizontal and vertical datum, units and the design revision used for checking. Specify how measured positions and elevations should be reported against that design reference.

Name who will assess whether deviations are acceptable. Keep measurement reporting distinct from an assessment of engineering compliance.

For each deviation, request an identifier, description and link to the relevant change order, RFI, submittal or instruction. Procore describes revision clouds, delta symbols, annotations and revision blocks as ways to flag changes, with reference numbers linking them to supporting records.[5]

5. Agree usable CAD, PDF or model outputs

Put the requested outputs into a file schedule covering format, software compatibility, drawing detail and copies. The OAA/OGCA statement recommends specifying format and software rather than leaving “electronic drawings” open to interpretation.[3]

• CAD: ask whether editable source files and external references are included, and agree layer conventions.
• Models: establish the intended use and recipient’s requirements before commissioning.
• Evidence and revisions: specify where survey dates, source labels, limitations and revision identifiers appear.

Get the file schedule confirmed before commissioning. Ask the recipient to review the proposed outputs alongside the measurement scope and professional responsibilities—not simply the file extensions.

6. Define professional responsibility

The document labels carry different responsibilities in the Ontario professional sources. The OAA/OGCA statement assigns contractor as-builts to the general contractor and treats architect-prepared record drawings as a separately agreed service, with limitations identifying reliance on contractor information.[3]

PEO’s terms of reference quotes a different distinction: third-party-based as-builts are unverified by the engineer and described as not to be sealed; record drawings are verified for accuracy and sealed by the engineer.[4] These are attributed definitions from that document, not a substitute for confirming the professional’s project-specific role.

Ask who measures, incorporates contractor records, reviews and signs or seals each document. Define those tasks rather than requesting a generic “certified as-built.” A surveyor-signed package should not be assumed to cover an architect’s or engineer’s separately agreed responsibilities.[2][3][4]

7. Confirm fees, terms and revisions

Request an itemised quote for measurement, drafting, investigation, professional review and revisions, with exclusions. The OAA/OGCA statement supports agreeing additional record-drawing services and fees in advance.[3]

The cited OCS and AKM pages do not state project prices, minimum terms, turnaround, cancellation terms or insurance details; OCS’s page also leaves precise municipal coverage, tolerances and licensed-signatory status unstated, while AKM’s leaves file formats and tolerances unstated. AKM offers a free quote.[1][2]

What to confirm with each provider

• Scope: coverage, tolerances, evidence limits, files and signatory.
• Fees: pricing basis, exclusions and extra charges for restricted access, missing records or repeat visits.
• Terms: quote validity, turnaround, payment milestones, cancellation and insurance.
• Revisions: included rounds, response times and responsibility for recipient comments.
• Changes: when extra work requires written scope and fee approval.

8. Check the handover against the brief

Cross-check changes against change orders, RFIs and submittals. Procore also identifies authority inspections, contractor inspections and the owner’s deficiency walkthrough as verification inputs.[5]

Before closing the commission, check:

• Agreed features, accuracy information, references and survey date.
• Measured-versus-supplied evidence labels and concealed-work limitations.
• Deviations linked to design and change records.
• Specified files and supporting documents.
• Named responsibilities, revision status and unresolved comments.

Keep receipt of files separate from the recipient’s review outcome. Record outstanding comments, who will answer them and whether further measurement or revisions are needed.

References

1. As-Built Construction Drawings & Surveying (ocsurveying.com)
2. As-Built Survey Toronto| Accurate Construction Surveys (akmsurvey.com)
3. Joint Best Practice Statement As-Built and Record Drawings (on.ca, 2010)
4. Terms of Reference Guideline for Preparing As-built and Record Documents (on.ca)
5. Understanding As-Built Drawings in Construction | Procore CA (procore.com)