Solar Roof Tiles in Ireland

Solar roof tiles are small solar units that take the place of the roof covering. The Energy Saving Trust notes that solar roof tiles are also called solar slates or solar shingles. Ordinary panels sit on rails above your tiles; solar tiles replace them. SEAI's homeowner guide describes the type, saying some solutions “allow for an integrated, ‘flush’, connection where the roof tiles are removed and replaced with the solar panels”. The grant is paid pro rata on the capacity installed, which is where this gets interesting for anyone re-roofing.

Tiles, In-Roof Panels and On-Rail Panels

All three turn up on quotes. They are not the same thing.

In-roof panels, the middle row in that table, are worth knowing about. EST says fitting the frame and panels to replace a section of the roof covering “gives them a cleaner, more streamlined appearance, but they're still noticeable since they look different to the remaining roof tiles”.

GB-Sol is a Cardiff maker of solar slates. Its PV Slate has been MCS accredited since 2018. It calls the product “a small solar panel that looks like a row of 4 natural slates”. The units lock into the slates around them to keep water out. They screw to ordinary roof battens with stainless steel screws. The wiring is nothing unusual. Standard MC4 connectors run back to an inverter, as GB-Sol puts it, “like any other solar installation”.

The Area Penalty Is the Real Number

Your south-facing slope is a fixed size, so output per square metre decides how big a system fits.

SEAI describes a conventional module as typically about 1.8m by 1.0m and around 20kg. GB-Sol gives a figure for its own product. PV Slates “can provide a peak solar output of 1kW from a roof area of around 7 square metres”. Compare that against the area a panel quote says it needs. Our guide to solar panel sizes and dimensions explains why watts per square metre is the number to compare.

The Energy Saving Trust's UK guide gives the general version: solar tiles are “less efficient per area than solar panels – typically producing only 80% of the electricity for the same area of solar panels”. Turned round, that means the same output needs about a quarter more roof. EST also says you can make up the gap by covering more roof, because the smaller units can be installed over a higher proportion of it. The situations it lists are awkward spots on angled roofs, roofs with dormer windows and other complicated layouts.

The figure that counts is the one on the datasheet for the product you are quoted, so ask for it.

Does the SEAI Grant Cover Solar Tiles?

The Solar Electricity Grant pays €700 per kWp up to 2 kWp, then €200 per extra kWp up to 4 kWp, capped at €1,800. SEAI pays it pro rata on the capacity installed. So the figure that sets your grant is the kWp on the roof.

A re-roof runs into several of the scheme's conditions harder than an ordinary job does.

• Approval comes before you buy. Clause 3 says you must have grant approval before “proceeding with any product purchase or installation work”. Spend before that and the cost is ineligible. It “may result in the entire Grant being withdrawn”. So do not order slates to suit the roofer's start date.
• The contractor has to be on SEAI's list. Clause 25 requires a Solar PV Company on SEAI's registered list, active when you apply and while the work is carried out. On the product side, SEAI's own words are that it “does not approve, guarantee, or warranty a company or their works”. The product rule is the Code of Practice. Clause 27 makes that a condition, and clause 35 lets SEAI claw back funds for “incorrect products as per the Code of Practice”.
• UK certification is not the Irish test. MCS is the British scheme, tied to British export payments. The Irish requirement is the one in clause 25: a company active on SEAI's registered list. Read MCS as a quality signal and check the registered list separately.
• A cheap job caps its own grant. Clause 4: the grant “shall not exceed the total cost of the works undertaken”. Where the works cost less than the grant, SEAI pays the cost of works only.
• The electrical sign-off still applies. Clause 28 requires an electrician registered with Safe Electric Ireland. Clause 29 requires a Safe Electric Certificate Number 3. Roofing work does not satisfy that. SEAI's registered installer is the one who signs the Declaration of Works.
• Age and ownership rules still apply. Clause 11 requires the owner of an existing home built and occupied before 1 January 2025. A new build does not qualify, whatever goes on its roof.

Together, those conditions point at one way to buy. GB-Sol says its slates “can be installed by an experienced roofer once trained”. For grant work, though, the contract sits with a registered Solar PV Company. Your roofer either works inside that contract or alongside it.

The VAT Split Nobody Mentions

Since 1 May 2023, solar on a private home is zero-rated for VAT when one firm supplies and installs it. Revenue's manual defines the term widely: “Solar panels include photovoltaic panels, solar windows, and solar walls.” A photovoltaic slate falls within that definition. Equipment that goes with it is zero-rated in the same contract. Revenue lists “the wiring, the controller, the combiner box, the batteries”.

The rest of the roof is not zero-rated. Revenue deals with exactly this case:

“Where solar panels are included in a supply and install contract that involves a range of other fixtures, the zero rate may continue to apply to the supply and installation of the solar panels and ancillary equipment to the solar panels; the other fixtures will be taxed at the appropriate rate (i.e. the reduced rate or standard rate).”

So picture one contract covering battens, membrane, natural slates round the edges and a solar slate array. The solar part is zero-rated. The roofing part is not. Revenue then applies a two-thirds test to the non-solar fixtures. If those fixtures come to two thirds of the contract value or less, the contract is charged at the reduced rate of 13.5%. Above that, the standard rate of 23% applies. Either way the solar element stays zero-rated.

One more line in the manual matters for how you buy. “The standard rate will apply to the supply of the solar panels if there is no installation contract in place with the supply of the goods.” Buy the slates yourself and hand them to your own roofer, and you pay 23% on the product. The work is then not being carried out by a registered Solar PV Company, which clause 25 requires. That is two problems from one decision.

Planning: Where Tiles Earn Their Price

Start with the ordinary house. S.I. No. 493 of 2022 rewrote Class 2(c) to exempt “the placing or erection on a roof of a house” of a solar PV system, with no cap on area. SEAI confirms the old 12 m² and 50% limits are gone nationwide.

Two conditions do apply to any roof array. Panels must sit no more than 15cm above the plane of a pitched roof, or 50cm on a flat one. And they must be “a minimum of 50cm from the edge of a roof on which it is mounted”.

On a tile roof, check the setback. The 50cm edge distance still applies. GB-Sol does specify a border: “Two natural slates are required around all edges of the roof and features such as roof windows.” It also sells a full-roof version taken “edge-to-edge” with custom infill slates. Get your installer to show you, on the drawing, that the PV units sit the full 50cm back from every edge. If they do not, the job is not exempt, whatever the brochure shows.

Protected structures are the real case for solar slates

The planning exemption is made under section 4(2) of the Planning and Development Act 2000. For a protected structure, section 57(1) of the same Act sets a further test on top of it. Despite those regulations, works to a protected structure “shall be exempted development only if those works would not materially affect the character of” the structure. The same test covers any element that gives it special architectural, historical, archaeological, artistic, cultural, scientific, social or technical interest.

On a protected structure, a rack of black rectangles is likely to count as affecting character. A grey slate that matches the slate around it may not.

The Act also lets you find out before you spend. Under section 57(2) an owner may ask the planning authority, in writing, for a declaration on what works would or would not affect the character of the structure. Under section 57(3) the authority has 12 weeks to issue it. A declaration that names solar slates is worth far more than an installer's assurance.

Condition 8 of Class 2(c) applies to an Architectural Conservation Area, and it restricts free-standing solar installations rather than roof-mounted ones. SEAI still advises that heritage homes, listed buildings and homes in Special Areas of Conservation contact their local authority before starting. It adds that a protected structure or a conservation area may bring further requirements. Our guide to solar panel planning permission in Ireland covers the general rules.

What They Cost

Two published figures are worth holding together. Neither is a quote for your roof, so get a quote as well.

For normal solar, SEAI's homeowner guide puts home PV at “around €1,500 - €2,000 per kW installed (ex-VAT)”. For tiles, the Energy Saving Trust's UK guide prices a typical 4 kWp tile job at about £12,000. It says that is more than panels fitted onto or into a roof, and puts tiles at normally about 1.5 times a panel install. EST calls panels the cost effective option for fitting onto an existing roof. That price leaves out stripping the old tiles, and it leaves out scaffolding. Our Irish solar panel cost page sets out what panel systems quote here by size.

There is a credit on the other side of the sum. EST notes tiles go on instead of normal tiles or slates during a re-roof, so “you'd have less material and installation costs for your new roof”. So the fair sum is not tiles against panels. It is a new roof plus tiles against a new roof plus panels, with the slates you no longer buy taken off one side.

EST is clear about the case where the roof has years left in it. Tiles are “only really cost effective if you are renovating the roof or building a new home”. It adds that if you are not redoing the roof, panels set into the roof may work out cheaper.

Durability and the Warranty to Ask About

A solar tile does two jobs. It keeps water out and it makes electricity. So the warranty has to cover both.

GB-Sol's PV Slate carries 25 years on product, performance and weatherproofing. Power output is warranted at 90% of nominal for 10 years and 80% for 25. GB-Sol notes that rivals built from plastics and adhesives “are often only able to offer warranty periods of 10 years”. The slates are tested to BS EN 61215 and BS EN 61730, plus EN 15601:2015 for weathertightness and a BS 476-3 EXT.S.AA fire rating. They are lighter than what they replace, up to 50% less weight than traditional slates.

Read the weatherproofing cover closely. SEAI calls water tightness the main risk in roof-integrated work: “The most important consideration for homeowners is that the water tightness of your roof is not affected by the installation.” Its guide also warns that installers “should not be permitted to drill into roof tiles to connect the PV panels, as this could lead to future leaks in your roof”. With tiles, the product and the roof covering are one object. A leak is a product problem and a roofing problem at once. Get both named in writing, with who covers each and for how long. Our guide to how long solar panels last in Ireland covers the lifespan side.

So Should You Fit Them?

Three common situations, and the sensible move in each.

One note on timing, from the clauses above: if the roof is coming off, line three things up early. Get the grant approved before anything is bought. Put the contract with a registered Solar PV Company. Ask for the VAT split on the quote.

Frequently Asked Questions