What this is, and why it matters
A field review report sealed by a Professional Engineer is a legal document. It records what an engineer saw on site, how it compared to the approved drawings and the Ontario Building Code, and what the contractor is expected to do next. When a sealed report is later read by a code official, a condo board, a tribunal, or another engineer reviewing the same work, the words in that report carry the force of the engineer's professional opinion.
Writing these reports is not a fringe activity. The corpus behind this analysis is large: real sealed field reviews and condition assessments written by licensed Ontario engineers for real projects, across multiple years and more than a dozen building-science and structural categories that dominate Ontario restoration practice, from balcony repairs and garage decks to curtain wall, roofing, and hydro vault rehabilitation.
What this article reports is not opinion. Every percentage below is measured against the classified corpus. The article exists because sealed fieldwork is undermetered: the industry produces tens of thousands of these documents a year in Ontario alone, but almost no structured data has ever been published about how they are written, what they contain, or where the drafting patterns break down.
Fermito publishes this analysis so the category's conversation about sealed fieldwork can start from data instead of anecdote.
The corpus
The corpus is a broad cross-section of Ontario restoration fieldwork: sealed reports written by licensed engineers for real projects, spanning multiple years and the categories listed above. The firm names are withheld. What matters for this analysis is the combined picture, not any single practice.
Two document shapes sit in the corpus. Most are enumerated field and site review reports: a site visit written up as a sequence of numbered observations. The rest are longer narrative condition assessments, which read as continuous prose rather than a numbered list. The observation-level findings below are measured on the enumerated field reviews, where the numbered observation is the unit of analysis. The condition assessments count toward the report-level patterns, the categories, the years, and the photo evidence, but not the per-observation statistics, because they do not carry a discrete observation to count.
What sealed fieldwork actually documents
Every observation in the corpus was classified by a large language model into one of 26 category labels covering concrete and structure, waterproofing and roofing, cladding and openings, fire and safety, and process work. We checked the model's output on a sample for accuracy. The labels are specific enough to be useful and general enough to hold up across different firms' drafting voices.
The top ten categories, and what share of all observations each one accounts for, are:
- Progress observation - 18.7%
- Waterproofing membrane installation - 9.4%
- Concrete placement - 8.5%
- Windows and doors - 8.5%
- Balcony guardrail - 7.4%
- Drainage and water management - 5.2%
- Sealant degradation - 3.7%
- Concrete deterioration - 3.7%
- Painting and coating - 3.6%
- Roofing assembly - 3.4%
The top five categories account for 52% of all observations; the top ten account for 72%. Restoration fieldwork in the GTA is dominated by a relatively narrow set of recurring conditions. Concrete deterioration, waterproofing failures, and the envelope repairs that follow from them make up the bulk of what engineers are writing about week after week.
Pillar-group rollup
Rolling the 26 labels up into five engineering pillars makes the pattern clearer:
- Envelope and water - 27.4%
- Cladding and openings - 23.7%
- Process and reference - 23.1%
- Concrete and structure - 22.1%
- Fire and safety - 3.7%
Together, the concrete-and-structure and envelope-and-water pillars account for roughly half of all observations. That is not a coincidence. Ontario restoration work is predominantly water management and the consequences of water management failure. When water gets into a reinforced concrete assembly, the resulting corrosion, spalling, and membrane reinstatement work shows up in field review reports for years afterward.
Report length and observation density
Reports in the corpus are shorter than many engineers expect. The median field review runs a few hundred words, shorter than the article you are reading, and the middle half fall between roughly 270 and 590 words. The longest tenth run past 800 words and tend to be final-review summaries covering multiple phases. The shortest are progress notes of a couple hundred words, usually produced during the middle of a multi-month repair when the engineer is visiting weekly.
Observation density matches this pattern. The median field review contains 5 observations, the 75th-percentile report contains 8, and the 90th-percentile report contains 13. Five to ten substantive observations per visit is the central tendency; the corpus rarely shows the kind of 30-item walkthrough list that some firm templates encourage.
This matters for drafting tooling. A generator that outputs 20 observations by default will feel wrong to most engineers. A generator that supports five to ten detailed observations per report, with the option to expand on the rare deeper review, matches what the corpus shows.
Photo evidence is near-universal, and photo density is high
Roughly nine in ten reports cite at least one photograph. The median report contains 5 photo references; the 75th-percentile report contains 7; the 90th-percentile report contains 9 or more.
More than half of observations directly reference a specific photograph by number, using language like "Refer to Photos #3 and #4" or "(Photo 1)". Photo evidence is not optional garnish in Ontario sealed fieldwork; it is woven into the observation itself. An observation without a photo reference is the exception, not the rule.
This has an uncomfortable implication for any drafting workflow. If the engineer cannot capture, caption, and attach photos to observations in the same session that produces the report text, the report is harder to write, and the photo-text linkage weakens. The corpus is effectively a proof that site-visit-to-sealed-draft workflows need photo-first tooling, not text-first tooling.
Regulatory citations are sparse at the observation level
Barely one observation in forty cites a specific code section, CSA standard number, PEO regulation, or named drawing reference inside the observation text. The rest carry the engineer's professional opinion about conformance with the drawings and specifications without anchoring that opinion to a named clause inside the observation itself. The citations that do appear are scattered; none clusters into a single dominant standard family.
This is not a gap in the engineering; it is a pattern in the drafting. Individual observations in the corpus are short. The regulatory context typically lives in the report's opening boilerplate, the referenced specifications, and the shared project drawings. What the corpus does not show is engineers repeating the citation inside every single observation, the way a compliance-checklist template would.
Interpretation. A sparse observation-level citation rate is not a quality judgement. It is a structural fact about Ontario sealed fieldwork that matters for AI-assisted drafting. A tool that tries to force a code citation into every observation will produce reports that look wrong to experienced engineers, because they do not match the corpus baseline. A tool that surfaces the right citation only when the observation type calls for it, CSA material standards for concrete placement, OBC Part 9 clauses for low-rise residential envelope, PEO Regulation 941 for sealing practice, is closer to what the corpus shows.
Revisions and multi-visit projects
Only a small share of reports carry an explicit revision indicator in the filename or document header, a "Rev 1", "Revision 2", "Re-issued", or an R-number suffix. This is a floor on the true revision rate because not every revised report is tagged that way; firms often replace the prior document without marking it as a revision.
A more telling signal of multi-visit drafting is the project chain. Most projects appear in the corpus once, usually because they were one-visit reviews or because only the final report was archived. But a tail of projects runs deep: the longest single-project chain in the corpus reaches dozens of sequential reports, each one a return visit as construction progressed.
The practical implication is that sealed drafting is not a one-shot activity. On the projects that do run long, every re-issue requires the engineer to re-read the prior report, re-construct the context, re-reference the same drawings and photo library, and decide which prior observations carry forward versus close out. Drafting tooling that treats every report as independent misses the single biggest source of productivity leak in that workflow.
Observation-to-recommendation ratio
A complete field review finding has three parts: what was observed, how it compares to the standard, and what should happen next. The corpus tells us the first two are nearly always present. The third is not.
About a third of observations carry an explicit, actionable recommendation, language that tells the contractor what to do next. The remaining two-thirds report a condition without an explicit directive. This is not a failure of the engineers; many observations are pure status notes ("progress is on schedule") where no recommendation is appropriate.
Looking at how observations resolve across the whole corpus, the most common disposition is simply documenting the condition for the record. Where engineers do direct action, the directives cluster into a few types:
- Document for record - 39% of observations
- Contractor to clarify - 10%
- Rework or replace - 9%
- Repair per detail - 6%
- No action / acceptable - 3%
- Further investigation - 3%
- Monitor - under 1%
Categories with the highest recommendation density (observation types where engineers almost always close the loop):
- Waterproofing failure - 67% carry an explicit recommendation
- Structural crack - 62% carry an explicit recommendation
- Windows and doors - 57% carry an explicit recommendation
Categories with the lowest recommendation density (observation types that tend to be status-only):
- Photo reference only - 1% carry an explicit recommendation
- Progress observation - 5% carry an explicit recommendation
- Equipment staging - 23% carry an explicit recommendation
How Fermito uses these findings
The corpus findings above shape what the product does:
- Photo-first, not text-first. Roughly nine in ten reports cite photos, and more than half of observations are photo-anchored. A drafting flow that starts with the photos and writes text around them matches the corpus shape.
- Five-to-ten observation default, not thirty. The median report has 5 observations, not 30.
- Recommendation suggestion as an option, not a default requirement. Only about a third of observations close the loop with a recommendation; forcing one on every observation creates reports that do not look like the corpus.
- Explicit revision chaining. The projects that run long are where the drafting time concentrates; carrying observations forward across a chain beats drafting each report from scratch.
Every percentage in this article is measured against the classified corpus. Firms running sealed work in Ontario that want the full categorical breakdown for internal training can contact Fermito.
