One job. Six stages. Entered once.
Below is a consumer unit change on a three-bedroom semi, walked from the first question to the signed certificate. The safety engine and the certificates are free on every tier; the job workflow that holds a board change in running order is Pro+, and the priced quote is Pro. Nothing in the sequence asks you to retype something you have already told it.
Add the job
Open the app and pick the job type from cards rather than a menu. Ring final, lighting circuit, shower, EV charger, three-phase board, and seventeen more. Consumer unit replacement and consumer unit layout are their own way in, on top of those.
Then Ohmly asks what it actually needs: the supply arrangement, the earthing system, Ze, the number of ways, the circuits going back in. One question per screen, large targets, answerable one-thumbed with gloves on.
Every wizard asks where the circuit is. That is not a nicety. Without it, the Section 701 bathroom checks cannot run, so the question is asked rather than assumed.
The circuits are drawn
The diagram is generated from the answers, using a consistent symbol set and BS 7671 conductor colours. Cable size, protective device and RCD selection are applied as it draws, not bolted on afterwards.
Then it becomes an open canvas. Drag components to match the way the board is actually laid out, add from the component tray, redraw a connection. The wizard builds the scaffold. The canvas is where you make it match reality.
Live power-path tracing runs the whole time. Green where the path is complete, amber where something is missing and it can tell you what, red where it will not work or is not safe.
Lighting circuit with two-way switching, as generated.
The checks run
Every determination is made against this design, on this supply, in this location. Not against a generic template, and not as a checklist you tick yourself.
Every figure Ohmly uses is checked against the published standard, read from a named edition and re-derived from the printed formula.
Where a determination needs something Ohmly has not been told, it names the input rather than assuming one. An EV circuit on a PME supply will not produce a design at all until the open-PEN decision is recorded, and that refusal is enforced where the circuit is assembled, not in the wizard where it could be skipped past.
All of this is on the free tier. A red critical cannot be dismissed. It can only be fixed.
Materials and quote
The parts list is extracted from the circuits you drew: cable by type and length, accessories, protective devices, glands and enclosures. Quantified, not estimated. Priced materials, costing and the customer quote are Pro.
Priced against your own figures, with your day rate, callout charge, markup and VAT status set once in your profile. Labour comes off the work in the design rather than being guessed at the end of the evening.
Then the customer quote is produced from the costing. You review it and send it. This is the half hour, most of it given back.
Figures are illustrative. Ohmly prices against the rates you set.
Checklist and tests
Safe isolation first, as five recorded steps rather than a single tick. Then the installation checklist, generated for the work in front of you rather than a generic list you have to filter.
Test results are entered against the expected values Ohmly already calculated from the design. Measure a Zs and it is compared to the maximum for the device you specified, on the spot, rather than back at the van.
The checklist and safe isolation are free on every tier. A measurement is stored as you typed it, so a 12.5 m run stays 12.5 m.
The certificate
Everything above is already in the certificate. The installation details, the supply characteristics, the schedule of inspections, the schedule of test results and the circuit details all come from the job rather than from you typing them again.
You review it, sign it on the device, and it is issued: numbered from your own register, locked against later editing, and logged when you send it.
Anything Ohmly was not told prints as "Not stated" rather than as an empty box that reads like an answer.
Illustrative layout. Ohmly designs its own certificate carrying the required content.
Three ways into the same six stages.
Most work is a change to something already installed. That is treated as a first-class route, not as an awkward version of designing from scratch.
New circuit
Designing from scratch. Answer the wizard, get the drawing, carry on down the chain.
Add to existing
Describe what is already installed and Ohmly renders it as a greyed baseline. Your change is drawn on top of it, so the diagram shows old and new. Fixing issues from an inspection report starts here too: describe what the report found, design the fix, and carry the observation through to the record of what was done about it.
Condition report
Survey a whole installation, board first. Ohmly opens a job flagged as a condition report, walks the boards and circuits as found, and steers the paperwork to an EICR at the end.
Learning is built in, and it is free. Lessons with a searchable index, a glossary, the symbol library and a safe isolation reference sit inside the app rather than on a website you cannot reach in a basement. It cites the regulation number for you to look up. It does not reproduce regulation text, which stays in the book you already own.
Quote to certificate. All in one place.
Add the job. Ohmly draws the circuits, runs the checks and writes the paperwork.