What Are the Benefits of Adding Solar PV During a Re-Roofing Project?

If you are already facing the cost and disruption of a full roof replacement, you are in a uniquely well-positioned moment to make a smart, long-term upgrade. Adding solar photovoltaic (PV) panels at the same time as your re-roof is not just convenient — it is almost certainly the most cost-effective window you will ever have to do it. At Severnside Roofing Specialists Ltd, we carry out re-roofing projects across Telford, Shrewsbury and Shropshire every week, and the question of solar PV comes up more and more. This guide explains exactly why combining the two jobs makes so much sense.

You Only Need the Scaffolding Once

Scaffolding is one of the most significant costs in any roofing project. Erecting, hiring and striking a scaffold for a typical two-storey house in Telford or Shrewsbury can add anywhere from £800 to £2,000 to the total bill, depending on the size and complexity of the property. If you have solar panels installed separately — even just six months after your re-roof — you will pay that full scaffolding cost again from scratch. By combining the solar installation with your re-roofing project, you share that cost across both jobs and make substantially better use of the access you are already paying for.

The same logic applies to any additional roofwork carried out at the same time. If you have been putting off adding Velux windows, sorting out a chimney, or addressing flashing around a stack, doing all of it while the scaffold is already in place is almost always the financially sensible move.

A Fresh Roof Is the Right Foundation for Solar

Solar PV panels are designed to last 25 to 30 years. If you bolt them onto a roof that is already fifteen years old and showing signs of wear, you are setting yourself up for an expensive problem further down the line — because when that roof eventually needs replacing, the panels will have to come off, the roof will be stripped and relaid, and the panels will need to go back on again. Each removal and reinstallation cycle adds cost, risk of damage to the panels and potential warranty complications.

By having your panels installed onto a brand new roof, both systems share roughly the same lifespan. Your new slates or tiles, laid as part of a full re-roofing project, will be in excellent condition for decades. There is no risk of needing to disturb the panels while the roof is still under guarantee, and the entire setup — new roof, new panels, new flashings — can be warranted and inspected as one coherent installation.

Roof Penetrations and Flashings Are Done Right First Time

Solar panels are mounted using brackets that penetrate or clamp onto the roof covering. If panels are added to an existing roof, those penetrations must be carefully flashed and sealed around existing tiles or slates that may be brittle, uneven or difficult to work around. Get it wrong and you create the very leak risk you were trying to avoid.

When panels go on during a re-roof, the roofer and solar installer can work in sequence on a clean, freshly laid surface. Roof hooks or clamp systems can be positioned precisely, lead or code 4 flashing can be integrated properly around penetration points, and tile cuts can be made cleanly on brand new material. The result is a watertight, neat installation with no compromises. Our team has extensive experience with roof repairs caused by poor flashing and penetration work — combining the two jobs properly from the outset eliminates that risk entirely.

Reduced Labour Costs Overall

Labour on a roofing project has a significant fixed element — time spent mobilising, setting up, preparing the roof deck and clearing away is spread across the whole job regardless of what else is being done on the same visit. When a solar installation is planned alongside a re-roof from the start, some of that labour overlaps. The roofers are already on site, the materials are already being managed, and certain preparatory tasks serve both jobs simultaneously.

A standalone solar installation on an existing roof also typically involves a separate survey, a separate installation crew, separate vehicles and separate project management time — all of which carry a cost that is passed on to the homeowner. Combining the two removes much of that duplication. For homeowners in Telford and Shrewsbury who are already investing in a significant re-roofing project, the marginal cost of adding solar at the same time is often considerably lower than the cost of a standalone solar installation later.

Better Structural Assessment Up Front

A re-roofing project involves stripping the roof back to the bare rafters, which gives your roofer a clear view of the structural condition of the timbers below. This matters for solar because panels add a modest but real load to the roof structure — typically around 10 to 15 kg per panel — and in older properties with undersized or damaged rafters, this needs to be assessed before panels go on rather than after.

When we carry out a full re-roof, we inspect the rafters, purlins and ridge board as a matter of course. Any timber that is soft, cracked or undersized can be sister-joisted or replaced before the new covering goes on, and any structural concerns about panel loading can be resolved at the same time. If solar is added to an existing roof without this underlying inspection, there is simply no way of knowing what condition the timbers are in — and no cost-effective opportunity to address it if problems are found later. Our building maintenance and new build experience means we routinely assess structural elements alongside the roof covering itself.

Energy Savings Begin Immediately

Every month you delay installing solar panels is a month’s worth of generated electricity you never benefit from. UK electricity prices have remained historically high in recent years and are not expected to fall significantly in the medium term. A well-specified 4kWp system on a south-facing roof in the Midlands will typically generate between 3,200 and 3,800 kWh of electricity per year — enough to cover a significant proportion of an average household’s consumption.

The payback period for a solar installation — typically six to nine years for a modern system — starts from the day the panels are commissioned. Every year of delay pushes that payback period further into the future. If your roof needs replacing anyway, waiting until after the re-roof to think about solar means losing a year or more of generation before the combined project is finally complete. Planning both together means panels can be commissioned as soon as the re-roof is signed off — often within the same week.

Planning and Permitted Development Is Simpler

In most cases, solar PV panels on a domestic roof fall within permitted development rights and do not require planning permission — provided they meet certain conditions around projection above the roofline and impact on the appearance of the property. However, if your property is in a conservation area or is a listed building, restrictions apply and a pre-application discussion with Shropshire Council’s planning department may be needed.

Handling this at the planning stage of your re-roof, rather than as a separate application later, keeps the process streamlined. If there are any conditions attached to the planning consent — for example, specifying the type of panel or limiting the installation to a rear slope — these can be factored into the re-roofing design from the outset, avoiding expensive alterations later. Our team works with homeowners on new builds and major renovation projects across Shropshire and is well placed to advise on what is and is not permissible in your area.

Integrated Roof Systems: In-Roof Solar vs On-Roof Solar

A re-roofing project also opens up the option of integrated, in-roof solar systems — where the solar panels replace a section of the roof covering entirely rather than sitting on top of it. In-roof systems are considerably more flush and unobtrusive than conventional on-roof mounting, which is important on properties where aesthetics matter or where there are planning sensitivities around the appearance of the elevation.

In-roof solar is significantly harder and more expensive to retrofit onto an existing roof covering, because it involves removing and relaying a section of tiles or slates to accept the integrated frame. During a full re-roof, this work is absorbed into the stripping and relaying process at a fraction of the standalone cost. If you are considering in-roof solar for a period property in Shrewsbury or a visible frontage in Telford, a re-roof is almost the only practical opportunity to have it installed properly.

Battery Storage: Plan the Cable Routes Now

Even if you choose not to install a battery storage system immediately, it is worth planning for one from the start. Battery storage allows you to store excess electricity generated during the day for use in the evening or overnight — substantially increasing the proportion of your own solar generation that you actually consume, rather than exporting to the grid at a lower rate.

The cable routes between the solar inverter, the battery and the consumer unit need to be planned carefully, and in a house that is being reroofed and potentially having other work done at the same time, it is far easier to run cables through the structure before everything is closed up and decorated. Adding battery storage as an afterthought in a finished property often involves unsightly surface trunking or expensive remedial work. Plan the infrastructure now and adding a battery later becomes a simple and tidy job.

Warranty and Insurance Alignment

Most re-roofing projects come with a workmanship guarantee — at Severnside Roofing Specialists Ltd, we offer guarantees of up to 25 years depending on the system specified. When solar is installed as part of the same project, the roof warranty and the panel installation warranty are aligned from the same start date by the same coordinating contractor. If there is ever any question about whether a leak or a structural issue is related to the roof covering or the panel installation, there is a single point of contact and a single coherent record of what was done and when.

A separate solar installation, carried out by a different company on a different date, creates a gap in accountability that can be difficult to resolve if problems arise later — each party pointing to the other as the source of any issue. Combining both under one coordinated project removes that ambiguity entirely. For emergency roof repairs and warranty claims, clarity about exactly what was installed and when is invaluable.

Is a Re-Roofing Project the Right Moment for You?

Not every homeowner facing a re-roof will find that solar PV makes financial sense — it depends on your roof’s orientation and pitch, your household’s energy consumption patterns, your plans for the property, and your budget. South or south-west facing roofs with a pitch between 30 and 45 degrees deliver the best generation figures in Shropshire’s climate. East or west-facing roofs can still be viable, particularly if you have high daytime energy usage. North-facing slopes are generally not recommended.

The best first step is a conversation with a roofing contractor who can assess both the roof structure and the panel positioning as an integrated question, rather than treating them as entirely separate projects. If you are in Telford, Shrewsbury or the surrounding areas and your roof is due for replacement, we would be happy to discuss whether combining solar PV makes sense for your specific property. Get in touch with our team for a free, no-obligation survey — we will give you an honest assessment and only recommend work that genuinely adds value.

Severnside Roofing Specialists Ltd are NFRC-approved roofing contractors based in Telford, serving Shrewsbury and all of Shropshire. Our services include re-roofing, flat roofing, roof repairs, dry ridge systems, EPDM rubber roofing, GRP fibreglass roofing and Velux window installation — all backed by up to a 25-year guarantee.