The design stage is where many STC problems start. Nobody asks who designed the system until a claim is audited, so it helps to know the rules from day one.
What the two accreditations mean
SAA accredits people in three ways: design only, install only, or design and install. An accredited installer is responsible for the safe, compliant installation. An accredited designer is responsible for a design that meets the standards: panel layout, string sizing, protection, cable selection and so on. The scheme treats them as separate duties.
| Designer | Installer | |
|---|---|---|
| Role | Specifies the system | Installs or directly supervises it |
| Needs an electrical licence | Check SAA’s entry rules | Yes, unrestricted |
| Can be done by the same person | Yes | Yes |
| Appears on the STC claim | Yes | Yes |
| Training | Design units | Install units, plus battery or SPS if relevant |
Accredited solar designer requirements
Requirements for design accreditation include approved design training, identity documents and an application to SAA, with the CPD that keeps it current. SAA’s entry rules differ from installer accreditation, and the categories (grid-connect, battery, SPS) matter. Confirm the current requirements on the SAA site before enrolling, and see the overview.
Who can design a solar system for STCs?
An SAA accredited designer for that kind of system. In a small business, that is often the same person who installs. In a larger one, a design team prepares the plans, and an installer then implements them. A salesperson sketching a roof layout is not enough, and design software does not replace an accredited person’s sign-off. For anything above 100 kW, which is now eligible for STCs from 1 October 2026 under the mid-scale rules, read mid-scale solar STCs because the design and eligibility rules shift with system size.
Do I need both?
- Sole trader doing everything: yes, both, or you cannot sign off the design and the install.
- Installer working for a retailer who supplies designs: you need installer accreditation; the retailer’s designer needs design accreditation.
- Designer working remotely: design accreditation only.
From the desk: an installer who changes the design on site, for example a different string layout, is stepping into the designer role. If you are not accredited to design, escalate to someone who is rather than improvising.
What this means for installers
Decide early whether you want one or both, because the training and fees differ (costs and steps). Design and installation both appear in the audit trail; see how STC audits work. When you are set up, start trading and see the installers hub.