The Solar Installation Process: What to Expect from Survey to Switch-On

Initial Consultation and Quote

Most installers offer free initial consultations by phone or video call. You will discuss your energy usage (annual kWh from your bills), roof orientation, and budget. The installer provides a preliminary quote based on this information, but it is not final — site surveys often reveal factors that adjust pricing.

Expect quotes within 3–7 days. A proper quote should specify the panel model and quantity, inverter type, mounting system, total cost, estimated annual generation, and payback period. Vague quotes lacking this detail suggest the installer has not properly assessed your needs — treat it as a red flag. For more on what a good quote looks like, see our guide to comparing solar panel quotes.

Site Survey

Site surveys typically take 1–2 hours. The installer assesses your roof condition, measures dimensions, checks orientation and pitch, inspects your consumer unit (fuse box), and identifies any obstacles such as chimneys, skylights, or shading from trees and neighbouring buildings.

They will also check loft access — inverters are often installed in lofts, requiring adequate space and ventilation. If your loft is inaccessible or heavily insulated, the inverter may need external mounting, which slightly increases costs.

Use the survey as an opportunity to ask questions: why did you recommend this panel configuration? What happens if we remove that tree? Could we add more panels in future? Good installers welcome questions and adjust designs based on your input. If they seem dismissive, that tells you something about their aftercare approach too.

Planning Permission and DNO Notification

Most residential solar installations do not require planning permission — they are classed as permitted development. Exceptions include listed buildings, conservation areas, flats, and installations where panels would protrude significantly above the roofline. Your installer should identify any planning requirements during the site survey. If you live in a conservation area in Durham or Newcastle, this is particularly worth checking.

All installations require Distribution Network Operator (DNO) notification. The DNO manages the local electricity grid and must approve your system’s connection. This process takes 1–4 weeks and is typically handled by your installer. Approval is usually automatic for systems under 3.68 kW; larger systems occasionally require grid capacity assessments.

Installation Day

Installation takes 1–3 days depending on system size and roof complexity. A typical 4 kW system on a straightforward roof is completed in one day. Larger systems or complex roofs require two days.

Day one involves scaffolding erection (if needed), mounting frame installation, and panel fitting. Day two covers the electrical work: inverter installation, wiring, consumer unit modifications, and grid connection. Some installers complete everything in a single day; others split mechanical and electrical work across two days.

You do not need to be home for roof work, but someone must be present for electrical work and the final handover. Expect noise from drilling, and power cuts of 1–2 hours for consumer unit work.

Commissioning and Handover

After installation, the system is commissioned: the installer tests all electrical connections, verifies the inverter communicates with panels correctly, and confirms the system exports to the grid. They will demonstrate the monitoring system (usually a smartphone app) and explain how to interpret generation data.

You will receive commissioning certificates, an MCS installation certificate (required for SEG registration), warranty documents, and system specifications. Keep these safe — you need the MCS certificate to claim Smart Export Guarantee payments, and the warranties for any future claims.

After Installation: SEG Registration and Monitoring

Register for the Smart Export Guarantee within 3–6 months of installation. You will need your MCS certificate and export meter readings (or half-hourly smart meter data). Compare SEG rates before committing — differences between suppliers amount to hundreds of pounds annually. Rates currently range from 4p to 15p per kWh depending on your supplier and tariff.

Monitor your system regularly via the app. Generation should match the installer’s estimates within 10–15%. Significant underperformance suggests faults or shading issues the installer missed. Contact them immediately if generation drops unexpectedly — most issues are resolved quickly if caught early.

Want to estimate what your system could save? Use our savings calculator to get a personalised estimate, or compare MCS-certified installers in your area to get started. Before you sign with anyone, make sure you know how to verify their credentials.