What should a solar panel installation quotation include?

A useful solar panel installation quotation should show how the system was designed for your property, what each part costs, and what assumptions the figures depend on. It should give you enough detail to compare quotations without guessing what has been left out.

The proposed system

The quotation should state the number of panels, their total capacity and their proposed position on the roof. It should show which roof faces are being used and explain any areas excluded because of shade, roof windows, chimneys or other obstructions.

Your roof may look suitable from the ground but still need closer inspection. We look at its condition, access, roof covering and the likely cable route before fixing the design. If repairs or structural work may be needed before installation, the quotation should identify that clearly rather than treating it as an installation-day surprise.

Expected generation should be based on the roof direction, pitch, shading and local conditions. The quotation should distinguish between modelled generation and a guaranteed output. It should also explain how much electricity you may use directly and how much may be exported, rather than presenting one headline saving figure.

Equipment details

Each major component should be named and described. That normally includes the panels, inverter, mounting system, monitoring equipment and any battery. If a battery is included, check that the quotation gives both its total capacity and its usable capacity, along with its intended role in the system.

The inverter controls how the panels’ electricity is converted for use in the home. Its position matters. A quotation should show where it will be mounted, how it will be ventilated and how the engineers will protect it from damp, excessive heat and accidental damage.

A battery quotation should explain how the battery connects to the solar system and what happens when the battery is full. It should also state whether the system can provide power during a grid failure. Solar panels and a standard battery do not automatically keep a house running when the grid is down.

Electrical work and connection requirements

The electrical section should explain the proposed cable route, isolators, protection equipment and connection point. Your existing consumer unit may need changes if it cannot accommodate the new generation equipment safely. The quotation should show this before work starts.

The installer should also consider the property’s earthing arrangement, meter position and the distance between the roof equipment, inverter, battery and consumer unit. Long or difficult cable routes can affect labour and materials, so they should be visible in the design rather than hidden in a general installation allowance.

Some systems need approval from the electricity network operator. A clear quotation should say whether an application or notification is required, who will make it and whether any network restrictions could affect the system’s export capability. This can matter when a battery is included or when the proposed generation is relatively large.

Access and work at the property

Roof work may require scaffolding, edge protection, lifting equipment or temporary access through the property. The quotation should say which access arrangements are included and which depend on the survey. It should also identify any likely disruption, such as access restrictions around the scaffold, drilling for cable routes or work in a loft or utility area.

An older, solid-wall or listed property may need more careful cable routing and a different approach to mounting equipment. If planning permission, listed building consent or another approval may apply, the quotation should flag that responsibility clearly. It should not assume that a standard roof installation is suitable for every building.

What the price actually covers

Ask the quotation to separate the main cost areas, even if they are later shown as one total. Look for the equipment, mounting materials, electrical work, access arrangements, commissioning, testing and documentation. Any optional battery, bird protection, roof repairs or monitoring package should be clearly marked as optional.

Potential extra costs should be specific. For example, a quotation may need to identify what happens if the survey finds damaged tiles, asbestos-containing materials, inadequate consumer-unit space or a cable route that cannot be used. A general clause allowing unlimited additional charges does not give you a useful basis for comparison.

Warranties and responsibility

The quotation should separate the manufacturer’s warranty for each component from the installer’s responsibility for the fitting work. It should explain who you contact if a panel, inverter, battery or monitoring system develops a fault, and whether any warranty depends on registration or regular maintenance.

It should also state what happens if one component fails while the rest of the system continues to operate. Clear fault-finding and warranty arrangements matter more than a long warranty period that is difficult to claim against.

Certification and export payments

For a solar installation, MCS certification gives you a route to apply for the Smart Export Guarantee with an eligible electricity supplier. The quotation should confirm whether the proposed system will be installed under the relevant MCS requirements and explain what certificates and handover documents you will receive.

The paperwork should cover the electrical test results, system information, commissioning details and any network notification. You should not have to reconstruct the system design later from invoices and photographs.

Questions to ask before accepting

• Which roof areas and shading assumptions were used for the generation model?
• Does the design include changes to the consumer unit, earthing or cable route?
• Are scaffolding, access equipment and making good included?
• What is the battery’s usable capacity, if one is proposed?
• Could the network operator limit export, and who deals with that process?
• Which certificates and monitoring details will be handed over?
• What work would be treated as an extra if the survey finds a problem?

We prepare quotations around the roof, electrical installation and way you expect to use the electricity. That makes the proposed equipment and predicted performance easier to understand before you decide, particularly where an older property needs more than a standard roof installation.