What is an MCS solar survey and what does it involve?

Before any panels go up, a survey establishes whether your roof is suitable and how the system should be designed. Done by an MCS-certified installer, it underpins both performance estimates and the certification you need. This page explains what it covers.

What MCS is and why it matters

The Microgeneration Certification Scheme (MCS) is the UK's quality assurance standard for small-scale renewable technologies, including solar PV. It certifies both the products used and the companies that install them, so an MCS-certified installation signals that the work meets a recognised standard.

It matters for two practical reasons. First, an MCS certificate for your system is normally required to enrol on a Smart Export Guarantee tariff and be paid for the electricity you export. Second, MCS certification gives you documented evidence that the system was designed and installed to standard, which is reassuring at the time and useful when you come to sell the property. Choosing an MCS-certified installer is therefore central to getting both a sound installation and access to export payments.

It is worth being clear that MCS certifies the company and the products, not a one-off inspection you arrange yourself. When you appoint an MCS-certified installer, the certification flows from their accreditation and the standards they work to, and the certificate is issued for your specific system once it is commissioned. That is why the choice of installer matters so much: an uncertified firm may fit perfectly good panels, but without MCS you would lack the certificate that suppliers require, and you would generally be shut out of the Smart Export Guarantee. The survey is the first visible step of working with a certified installer, but the certification underpins the whole process.

What the survey assesses

The survey is where the installer establishes whether your property suits solar and how to design the system. Typically it covers:

• Roof structure and condition — whether the roof can bear the load and has enough remaining life, since it is best to recover an ageing roof before fitting panels.
• Orientation and pitch — which way the roof faces and at what angle, both of which strongly affect generation (south-facing at a good pitch is ideal, but east and west work well too).
• Shading — chimneys, trees, aerials or neighbouring buildings that cast shadow, which may steer the design toward microinverters or optimisers.
• Available area — how many panels physically fit, setting the practical system size.
• Electrical system — the consumer unit, existing wiring and where the inverter and any battery would go, plus grid connection considerations.

From these findings the installer designs the array, estimates realistic annual generation for your specific roof, and confirms the system can be installed to MCS standards.

Indicative survey scope for guidance only. Source: MCS.

What you get from the survey

The output of the survey is a system design and a realistic proposal for your property: the recommended number and layout of panels, the inverter type, whether a battery is sensible, and an estimate of annual generation based on your actual roof orientation, pitch and shading rather than a generic figure. This is far more reliable than an off-the-shelf quote, because it reflects your specific home.

It also confirms that the installer can deliver an MCS-certified installation, which is what produces the MCS certificate you will need for the Smart Export Guarantee. If the survey flags an issue — an ageing roof, heavy shading, or an electrical limitation — it is far better to know before installation than after. A thorough survey is therefore a good sign of a careful installer, and it gives you the information to decide whether to proceed and to compare like-for-like with other quotes.

How to use the survey when comparing quotes

Because each installer surveys your roof and designs to it, the survey is also your best tool for comparing quotes fairly. Two proposals can differ for sound reasons — a different panel layout to work around shading, a different inverter choice, or a different view on whether a battery is worthwhile — and the survey detail is what lets you understand why. A few things are worth looking for:

• A realistic generation estimate tied to your roof's orientation, pitch and shading, not a generic national figure.
• A clear panel and inverter specification, so you can compare like with like rather than just headline prices.
• An honest assessment of any issues — an ageing roof, awkward shading or an electrical constraint — rather than a quote that glosses over them.
• Confirmation of MCS certification, since that is what underpins both quality and your access to export payments.

An installer who carries out a careful survey and explains their design is demonstrating exactly the diligence you want, because the survey is where a system is made to fit a home rather than imposed on it. If a quote arrives without a proper survey, or with an estimate that looks generic, that is a reason for caution. Used well, the survey turns solar from a leap of faith into an informed decision: you know what will be installed, roughly what it will generate, and that it will be certified to the standard the Smart Export Guarantee requires.

Frequently asked questions

Sources & further reading

• MCS — The Microgeneration Certification Scheme
• Energy Saving Trust — Solar panels

Figures on this page are typical UK ranges drawn from published sources and depend on your specific home. They are guidance, not a quotation or guaranteed saving.