The Commercial Solar Installation Process: Step by Step

Embarking on a commercial solar project can feel daunting if you have never done it before. The good news is that a well-managed installation follows a clear, predictable process with defined milestones and deliverables at each stage. Understanding this timeline helps you plan around operational downtime and set realistic expectations.

The process begins with a free site survey and energy assessment. An accredited surveyor visits your premises to evaluate roof structure, electrical infrastructure, shading patterns, and orientation. They also review your last 12 months of electricity bills to model consumption patterns and size the system accordingly. This stage typically takes one to two weeks, and you receive a detailed feasibility report including financial projections.

Once you approve the proposal, the design phase begins. Our engineers produce structural calculations confirming the roof can safely support the panel array, along with electrical schematics and single-line diagrams. Simultaneously, we submit a Distribution Network Operator (DNO) application to connect your system to the grid. DNO approval can take four to twelve weeks depending on your local network capacity, which is why we submit immediately after contract signature.

Planning permission is rarely required for rooftop solar on commercial buildings, but there are exceptions. If your building is listed, in a conservation area, or the installation exceeds certain size thresholds, a permitted development assessment is necessary. Our team handles all planning liaison as standard, keeping your project on track.

The physical installation typically takes one to three weeks depending on system size. Scaffolding goes up first, followed by rail mounting, panel placement, inverter installation, and DC/AC cabling. Most commercial installations can proceed without interrupting your normal operations, though brief electrical isolation may be required during final connection.

After installation, the system is commissioned by a certified MCS installer and tested to confirm it meets all safety and performance standards. We then register your installation on the MCS database and submit your Smart Export Guarantee application. Finally, we provide a full handover package including operation and maintenance manuals, performance monitoring login credentials, and a 25-year panel warranty certificate. From first survey to switch-on, most projects are completed within 12 to 16 weeks.