A structural engineer's report records what was seen, the likely cause and what should be done. A shorter letter gives the same opinion in brief. Stamped drawings are a repair design: member sizes, grades, fasteners, footings and notes a contractor builds from and a permit office reviews. Stamping, signing and dating means the licensed engineer takes professional responsibility for that document.
- Match the document to the need: a letter for an opinion, a report for detail, drawings for a permit and a build.
- Every good report states its scope and limits, such as visual only, no destructive testing and areas not accessible.
- Stamped drawings are instructions, not suggestions; substitutions need the engineer's written approval.
- Field reviews and a completion letter close the loop and are valuable at resale.
- Keep every engineering document with the house records; they transfer value to the next owner.
01 /What is a structural engineer's report?
A structural engineer's report is a signed document that records the condition of a structure, the engineer's opinion on the cause of any problem, and recommendations. For houses it usually follows a site visit and is written for the owner, although lenders, insurers, buyers and municipalities may also read it. The report's value lies in its specificity: which member, how much movement, what caused it and what to do, in what order.
Reports range from a one-page letter to a twenty-page condition assessment with photos and floor elevation plots. Longer is not better; the right length depends on the question. A buyer asking whether a crack is a concern needs a clear opinion quickly. An owner with a settling corner, three contractors quoting different fixes and an insurer asking questions needs the full record.
02 /What should a structural report include?
A useful structural report covers seven things. If one is missing, ask for it before you rely on the report.
- Purpose and scope
Why the engineer was engaged, what was examined and what was not. "Visual review of the basement and main floor framing; the attic was not accessed" is the kind of sentence that matters later.
- Description of the building
Age, construction type, foundation type, framing system and relevant renovations, so the reader understands the context.
- Observations
What was seen, with locations, photographs and measurements: crack widths and offsets, wall bow, floor elevations, member sizes and spans, moisture readings.
- Opinion on cause
The engineer's professional opinion on why it is happening, and how confident they are. Good reports say when a cause is probable rather than certain.
- Whether it is active
Stable, seasonal or progressing, and on what evidence. When the evidence is not there yet, a monitoring plan with dates.
- Recommendations and priority
Immediate, short-term and long-term items, specific enough for contractors to price, and whether engineered design is needed.
- Limitations
The standard statement that the review was visual and non-destructive, that concealed conditions may differ and that the report is not a warranty. These are normal and honest, not a sign of a weak report.
03 /What is the difference between a letter, a report and drawings?
| Document | Length | Answers | Right for |
|---|---|---|---|
| Site visit letter | 1–3 pages | Is this structural? What is the likely cause? What next? | Most homeowner questions, pre-purchase opinions |
| Condition assessment report | 5–20+ pages | Full record, measurements, cause, options, priorities | Complex or disputed problems, insurance, larger repairs |
| Repair design drawings | 1–6 sheets | Exactly what to build and how | Permits, contractor pricing and construction |
| Design calculations | Varies | The engineering behind the sizes | Sometimes requested by the permit office |
| Field review report | 1–2 pages | Was each stage built as designed? | Before footings are poured or framing is covered |
| Completion or compliance letter | 1 page | The work observed generally conforms with the design | Permit close-out, resale files |
A letter or report says what should happen; drawings say how. A report that recommends "install a beam to support the joists" cannot be built or permitted until someone designs the beam. If the recommendation involves new members, footings or piers, expect a separate design step, and a separate fee, before contractors can give firm prices.
04 /How do you read structural drawings?
Residential structural drawings are usually a few sheets combining plans, sections, details and notes. Read them in that order: the plan shows where, the section shows how things stack, the detail shows the connection and the notes govern everything.
- Plan view. Looking down on a floor: which joists, beams and posts are new or existing, spans, member marks (for example B1, P1, F1) and dimensions from known walls.
- Schedules. A table that defines each mark: B1 might be a built-up laminated veneer lumber (LVL) beam of stated plies and depth, P1 a steel post of a stated size, F1 a concrete footing of stated plan size and thickness.
- Sections. A slice through the house showing the load path from roof or floor down to the footing, including blocking that carries a post's load through floors.
- Details. Enlarged connections: hangers, bolts and their spacing, bearing lengths, how a sister joist is fastened, how a brace attaches to the floor framing.
- General notes. Material grades, concrete strength, fastener types, temporary shoring requirements, sequence, and which stages the engineer must review. Notes carry the same weight as the drawings.
- Title block. Project address, drawing number and revision, date, and the authenticating stamp, signature and date.
If something on site does not match the drawings, such as a joist that is smaller than shown, a duct where a post should go, or no footing where one was assumed, the contractor should stop and ask the engineer. A good engineer answers with a written clarification or revised sketch, which becomes part of the record.
05 /What does it mean when drawings are stamped?
A stamped (or sealed) drawing has been authenticated by a licensed engineer, who takes professional responsibility for its content. Each regulator sets the rules. In Alberta, APEGA's practice standard on authenticating professional work products, revised effective November 1, 2024, requires the licensed professional's stamp, their APEGA ID, a signature across the stamp and the date; the firm's Responsible Member separately validates the work with permit information. Digital authentication in Alberta uses an approved digital signature rather than a pasted image.
Practical consequences for a homeowner:
- Do not alter stamped drawings. A marked-up stamped drawing is no longer the engineer's document. Changes go back to the engineer for a revision.
- Substitutions need approval. A contractor wanting a different beam material, post or fastener needs the engineer's written acceptance, even if the substitute seems stronger.
- Check the stamp is current. Verify the engineer on the regulator's public directory, such as APEGA's member directory in Alberta, if you have any doubt.
- Keep them. Stamped drawings, field reviews and completion letters answer a future buyer's or inspector's questions better than any receipt.
06 /What are field reviews and why do they matter?
A field review is a site visit by the engineer, or someone under their supervision, during construction to check that the work generally conforms with the design at critical stages. For house repairs, typical review points are footing excavations before concrete, reinforcement before a pour, beam and post installation before drywall, pier installation records, and bracing before finishes cover it.
Some municipalities require engineer field reviews and a final letter when engineered drawings form part of a permit; others leave it to the engineer's drawing notes. Either way, reviews are cheap insurance. A post placed over a buried pipe instead of a footing, or a bolt pattern halved to save time, is easy to fix before drywall and expensive after. Ask the engineer up front which reviews they need, schedule them with the contractor, and do not let finishes go up until the relevant review is done.
Ready to engage an engineer? Read what a structural engineer does for hiring steps and fees, and structural repair permits for how drawings fit the permit process. HAUSE Home, the independent network behind StructuralRepair.ca, is not an engineering firm, but you can send a request and the desk will reply with next steps.
FAQQuestions people ask
What is a structural engineer's letter?
A short signed document, usually one to three pages, giving the engineer's opinion after a site visit: what was observed, the likely cause and recommended next steps. It is the most common document for homeowners and buyers.
Can I use a structural report to get a building permit?
Usually not on its own. A report recommends what to do; a permit usually needs drawings showing exactly what will be built. If the repair is engineered, the engineer prepares authenticated drawings for the application.
How long is a structural engineer's report valid?
There is no fixed expiry, but it describes conditions on the date of the visit. If the problem is active, or months have passed before a purchase or repair, ask whether an update visit is needed.
Can a contractor change an engineer's design?
Not on their own authority. Changes, substitutions and field fixes need the engineer's written acceptance, because the engineer carries professional responsibility for the design.
Do I need a completion letter from the engineer?
Sometimes a municipality requires one to close a permit, and it is always useful at resale. It confirms that the work the engineer observed generally conforms with the design.
Why does the report say it is not a warranty?
Because engineering assessments are professional opinions based on what could be seen and measured. Stating the scope and limits is standard practice and protects both you and the engineer from misunderstandings.