These terms are the agreement between you and GreatCallie International Ltd (Nigeria) for the use of Structura — the mobile apps, the web app and the server behind them. Creating an account or signing in means you accept them.
Questions about anything here: calistusokwudili@gmail.com. See also the privacy policy, which covers what we hold about you.
The part that matters most
Structura is a preliminary design tool, and you are the reviewing engineer. A PASS on a calc sheet means the design checks out for the loads and dimensions you entered. It does not mean a building is safe to build, and it is not an approval.
Every output must be reviewed and approved by a licensed structural engineer before construction. Nothing Structura produces is a substitute for that judgement, for a site investigation, or for the approvals your jurisdiction requires.
What the engine does and does not do
Structura implements BS 8110-1:1997 in plain, deterministic code, and shows its working: formula, substituted values and a PASS or FAIL on every check. Its limits are stated on the sheets themselves and are part of these terms:
- No seismic design, no piled foundations, and settlement is not calculated.
- Gravity-only designs stop at three suspended floors; above that a wind path is required.
- Wind uses a simplified static method, and the basic wind speed you enter is used as given — as an effective gust speed, with no terrain or height factor applied on top. There is no Nigerian wind map built in.
- Bar bending schedules use simplified anchorage and lap assumptions, stated on the sheet, to be confirmed at detailing. Beam–column joint design is not included.
- Fire and robustness-tie figures are tabulated standard values for a stated exposure. The real requirement depends on occupancy, aggregate and exposed faces, which the app does not know, so they must be confirmed.
- Quantities in the bill are priced with rates you set. The rates are yours; the prices they produce are yours.
A design that fails is meant to fail loudly and say what to change. If you believe a result is wrong, tell us through Help → Feedback in the app rather than working around it.
Your responsibilities
- The inputs are yours: spans, loads, soil bearing capacity, material grades and everything else. A design is only as good as them.
- Check every result before it leaves your desk, and hold the professional registration and insurance your work requires.
- Keep your password to yourself. An account is for one person, and what happens under it is treated as done by you.
- Give an address you can receive mail at — it is how a password is reset.
Credits and payment
- Single members — slab, beam, column, footing, stair, lintel, raft, wind — are free, however many you run.
- A credit unlocks one project: a whole-building takedown or a column grid. Revising that project, re-running it and re-exporting it stay free afterwards, with no time limit.
- Credits are bought on this website, in the currency shown, through Paystack. Card details never reach Structura.
- Prices are set on the server at the moment of purchase. What you are charged is what the pack cost when you bought it.
- Credits are not refundable, and are forfeited if you delete your account — except where consumer law says otherwise. If a payment is taken and no credits arrive, write to us and we will fix it.
- An unpaid design still runs in full and still tells you whether the building passes and what is wrong with it. What a credit buys is the calc steps, the bar schedule, the bill of quantities and the drawings.
What belongs to whom
Your work is yours. The designs, calc sheets, schedules, bills and drawings you produce with Structura are yours to use, issue and be paid for, with no claim from us and no attribution asked.
The software, the engine and the site remain ours. You may not resell access, share one account across a practice, automate the API outside the app, or attempt to extract the calculation engine.
Availability, warranty and liability
Structura is provided as it is. We work to keep it correct and available, but we do not warrant that it will be uninterrupted, or that every result will suit every case. Service may be interrupted for maintenance or by our providers.
To the fullest extent the law allows, our total liability to you for anything arising out of Structura is limited to what you have paid us for it in the twelve months before the claim. We are not liable for construction cost, delay, rework, or loss of profit or reputation.
Nothing here limits liability that cannot lawfully be limited, including for death or personal injury caused by negligence, or for fraud.
Ending it
You can stop at any time and delete your account — in the app at Settings → Delete account, or at /delete-account. What is removed and what is kept is set out there and in the privacy policy.
We may suspend or close an account that is used to break these terms or the law. Where we do that without cause, unused credits are refunded.
Changes, and the law that applies
These terms may change as Structura does. The date at the top says when they last did, and material changes are notified by email to the address on your account. Continuing to use Structura after that means accepting the new terms.
This agreement is governed by the laws of the Federal Republic of Nigeria, and the courts of Nigeria have jurisdiction.