The structural half of a building plan submission is a small, predictable set of documents. Most of the delay in getting a permit is not the engineering — it is a package that is missing one sheet, or drawings that no longer match the architect's latest plan.
Requirements differ by state and by authority, and they change. What is below is the shape of a typical submission for a residential building; confirm the specifics with the physical planning authority for your state before you print anything.
The four documents
- The structural drawings — the set below.
- The structural calculations — a bound sheet showing how the members were sized, not just the answers.
- The soil investigation report, where the authority asks for one, stating the allowable bearing pressure the foundations were designed to. See soil bearing capacity for when that stops being optional.
- Professional certification — the drawings and calculations signed and stamped by an engineer registered to do it, with the architectural drawings signed by the architect. Engineering practice in Nigeria is regulated by COREN, and an unstamped structural drawing is the single most common reason a package is not even looked at.
The drawing set, sheet by sheet
| Sheet | What it must show |
|---|---|
| General notes | Concrete grades by element, steel grades, cover by element, design code, imposed loads assumed, soil bearing pressure used, and what is to be confirmed on site |
| Foundation layout | Every footing located and dimensioned off a setting-out grid, with a footing schedule — size, depth, reinforcement — and the founding level stated |
| Foundation details | Sections through each footing type showing the bars, the blinding and the ground beams |
| Column layout and schedule | Column positions per storey, sizes, main bars and links, and where a column changes size or stops |
| Floor framing plan | Beam and slab layout per suspended floor, with member marks tying back to the schedules |
| Slab reinforcement | Bar size, spacing, direction and extent, top and bottom, per panel |
| Beam details | Elevations with bar arrangements, curtailment, links and their spacing zones |
| Staircase details | Section through the flight, waist, bars, and the landing connection — see stair design |
| Bar bending schedule | To BS 8666, per member mark, with shape codes and cutting lengths |
The set is a chain of references, and that is what a reviewer checks first. A beam called B3 on the framing plan has to be B3 in the beam details and B3 in the schedule. Marks that do not line up read as a set assembled from two different revisions — because usually they were.
What the calculation sheet has to show
A page of results is not a calculation. What a reviewer is looking for is the ability to follow the load from the roof to the soil:
- The loading assumed — dead load built up item by item, imposed load with the occupancy it came from, and the combination used.
- A load takedown showing the column loads accumulating storey by storey.
- Each member designed with the formula, the substituted numbers and the check — not just the final bar size. "T16 @ 150" with nothing behind it cannot be reviewed, only believed.
- The serviceability checks, especially deflection, which is what actually governs most slabs and stairs.
- The foundation design, with the bearing pressure stated and its source named.
- Any assumption that would change the answer if it were wrong, written where it can be found rather than held in the designer's head.
What gets a package sent back
| Cause | The fix, before you submit |
|---|---|
| Structural does not match architectural | Check the revision of the architectural plan you designed from is the one being submitted. Column positions and openings are where they diverge |
| No stamp, or the wrong person's | Signed and stamped by a registered engineer, on every sheet, not just the cover |
| Calculations absent or results-only | Submit the workings, in order, load path first |
| No soil data for the foundation used | State the allowable pressure and where it came from; attach the report if one exists |
| Drawings not to a stated scale | Scale on every view, with a title block and a revision box |
| Missing sections and details | A plan alone does not show a stair, a footing or a beam-to-column arrangement |
| No bar bending schedule | Include it — it is also what the steel is ordered and checked against on site |
Where Structura fits, and where it does not
Being exact about this matters more than selling it. Structura produces:
- The calculations, as a step-by-step sheet with the formula, the substituted values and a PASS or FAIL on every check — exported as a branded PDF report with the load takedown, every member and the assumptions listed.
- A foundation layout general arrangement, with the footings located and a schedule beside them.
- A column application plan with its schedule — one per storey where the building steps in, with the columns that have stopped below drawn dashed so a gap cannot be read as an omission.
- A floor framing plan per suspended floor and for the roof: every slab panel marked, with its thickness and the way it spans, and every beam marked along its line, tying back to the member sheets and the schedules.
- A detail sheet per member — sections and elevations to scale, dimensioned, with bar callouts and the bar bending schedule on the sheet — as PDF to issue or DXF to open in AutoCAD and drop into your set.
- The bar bending schedule to BS 8666 and the costed quantities.
It does not produce the architectural background or any setting-out beyond the structural grid, and it does not stamp anything. The output is the engineering, in a form a technician can assemble into a set and a registered engineer can review, correct and take responsibility for. A PASS from the engine is not an approval, and every sheet it prints says exactly that.
It has real ceilings too, and they belong in this conversation rather than after it: no seismic design, no piles, no settlement calculation, and a wind method that is a clearly labelled simplification. What it will not do is a page of its own, written so you find out before you rely on it.
Get the calculations done first
The calculation sheet is the part of the package that takes the longest and gets queried the most. Structura designs the whole building — takedown, slabs, beams, columns, footings, stairs — and prints it in the order a reviewer reads it. Single members are free to run, as many as you like, so you can check a member you have already sized by hand before you commit to anything.
Open Structura in your browser
On Android, get it on Google Play; on iPhone and iPad, get it on the App Store — same account as the browser.