Asbestos Roof Replacement and Solar Installation — Turning a Problem Into an Asset

There are millions of square metres of asbestos cement roofing on agricultural, industrial and commercial buildings across the UK. Much of it was installed in the 1960s, 1970s and 1980s. It is reaching the end of its serviceable life. And for the owners of those buildings, it represents one of the most significant barriers to installing solar panels.

This post is about why that barrier exists, what the options are, and why addressing the asbestos roof replacement and the solar installation together changes the financial case in a way that addressing them separately does not.

Why Asbestos Roofs and Solar Do Not Mix

The problem is straightforward. Solar panels are warranted for 25 years. They are fixed to a roof structure and, in most cases, cannot sensibly be removed and reinstalled without significant cost and disruption. Installing solar panels on an asbestos roof that is likely to need replacing within the next decade is therefore a poor decision, regardless of how good the solar economics look.

Asbestos cement roof sheeting, the corrugated grey material found on the majority of older agricultural and industrial buildings, is a specific category of asbestos-containing material. The cement matrix means the asbestos fibres are generally well-bound and not immediately hazardous in the way that loose-fill asbestos insulation can be. But the material does degrade over time. As it weathers, it becomes more friable. Lichen and moss growth accelerates surface deterioration. And any drilling, cutting or fixing into the sheets, as would be required for solar panel installation, creates a regulatory and health and safety problem that responsible installers will not take on.

The result is a category of building owner who wants solar, can clearly see the financial case and is blocked by the roof condition before the conversation about system design even begins.

The Agricultural Building Challenge

For farming businesses, the asbestos roof problem is particularly acute.

Agricultural buildings are well suited to solar in almost every other respect. Large, south-facing or near-south roof areas. Significant daytime electricity consumption from grain drying, irrigation, refrigeration, water pumping and general farm operations. Rural grid connections that, while sometimes requiring reinforcement, are increasingly supported by DNOs pursuing decarbonisation targets. And a business case for energy cost reduction that has strengthened considerably as agricultural energy costs have risen.

The barrier is the economics of the roof replacement itself.

Replacing the asbestos roof on a large agricultural building is a significant capital cost. It is also, when considered in isolation, a maintenance spend with no financial return. You replace the roof because you have to, not because it generates revenue. For many farming businesses operating on tight margins, that cost is difficult to justify. The roof gets patched and monitored rather than replaced. The solar panel installation that would have made commercial sense does not happen.

This is where the combined approach changes everything.

When the asbestos roof replacement and the solar panel installation are considered as a single project, the financial picture shifts fundamentally. The roof replacement is no longer a sunk cost. It becomes the foundation of an energy-generating asset. The combined capital expenditure starts earning a return from day one of operation. The payback period is calculated against the whole investment, and the solar generation income contributes to recovering the roofing cost alongside the installation cost.

A building that was a maintenance liability becomes a revenue-generating asset. That is not a marginal improvement to the financial case. It is a different financial conversation entirely.

The Industrial and Commercial Case

For industrial and commercial property owners, the calculation is somewhat different but the conclusion is the same.

Industrial and commercial clients typically have capital budgets for building maintenance that can accommodate a roof replacement. The roof will be replaced when it needs replacing, one way or another. The question for these clients is not usually whether they can afford to replace the roof, but whether they have joined up the thinking between the maintenance budget and the energy strategy.

In practice, many commercial property owners replace an asbestos cement roof and then, months or years later, begin a separate conversation about solar panel installation. They end up with a new roof, a solar installation quotation and the realisation that the process would have been significantly simpler and more cost-effective had both been considered at the same time.

The cost of solar installation on a new roof is lower than the cost of installing on an existing roof, then removing panels for future roof work, then reinstalling. The disruption is concentrated into a single programme. The planning and project management overhead is shared. And the business case, as with agricultural clients, is stronger when the full combined investment is treated as a single asset rather than two separate costs.

What the Process of Asbestos Roof Replacement and Solar Installation Looks Like

Managing the asbestos roof replacement and solar installation as a single project requires a contractor who can handle both, or a project manager who coordinates the two workstreams under one point of accountability.

SPI Renewables manages this process for clients where the roof condition is a barrier to solar installation. We work with specialist asbestos cement roofing contractors and act as the single point of contact throughout the project, from initial survey and feasibility through to solar commissioning and long-term aftercare.

The process typically runs as follows.

A combined survey assesses the existing roof condition, the asbestos type and risk classification, the structural capacity of the building for both the new roof and the solar loading, and the solar potential based on orientation, shading and energy consumption.

A combined feasibility report sets out the roof replacement options alongside the solar system design and the integrated financial case, covering the combined capital cost, projected solar generation, energy savings, export revenue and payback period.

The roof replacement is carried out first by specialist contractors working to current asbestos removal and disposal regulations. SPI coordinates this programme and manages the handover to the solar installation phase.

The solar system is then installed on the new roof structure, commissioned and handed over with full MCS documentation, monitoring setup and an aftercare arrangement in place.

One project. One point of contact. The combined outcome is a building with a new roof and a solar installation that starts generating a financial return from the day it is commissioned.

A Note on Asbestos Regulations

Asbestos cement roof replacement must be carried out by licensed contractors working to Control of Asbestos Regulations 2012. The work requires a written plan of work, notification to the Health and Safety Executive in most cases, appropriate personal protective equipment and licensed disposal of the removed material.

This is not a task for a general building contractor or a solar installer who has not worked with asbestos-containing materials. SPI does not carry out the asbestos removal work directly. We work with licensed specialist roofing contractors and manage the overall project. Any contractor we work with operates to the required regulatory standard.

Overcladding, where a new roof is installed over the existing asbestos sheets rather than replacing them, is sometimes proposed as a lower-cost alternative. This approach has significant limitations. The condition of the underlying sheets continues to deteriorate. The structural loading implications require careful assessment. And for solar installation, the additional roof build-up affects the mounting system and needs to be properly engineered. SPI assesses overcladding options where clients raise them and advises on whether they are appropriate for the specific building and solar installation planned.

The Questions Worth Asking Before You Start

If you own or manage a building with an asbestos cement roof and you are considering solar, the conversation needs to start with the roof, not the panels.

What is the current condition of the roof, and what is its likely remaining serviceable life? If the answer is less than 15 years, installing solar without addressing the roof first is not a sound investment.

What is the asbestos type and risk classification? Asbestos cement is generally lower risk than other asbestos-containing materials, but a proper survey by a qualified asbestos surveyor is the right starting point.

What does the combined financial case look like? The roof replacement cost, the solar system cost and the projected solar return need to be modelled together, not in isolation.

Who is going to manage the overall project, and how is accountability structured between the roofing contractor and the solar installer?

SPI Renewables is happy to have that conversation before any commitments are made. A combined survey and feasibility assessment is the right starting point, and it costs nothing to understand whether the numbers work for your building.