When Is a Glint and Glare Assessment Required in Ireland?

What Is a Glint and Glare Assessment?

A glint and glare assessment is a reflectance impact study that predicts whether solar PV panels will cause problematic reflections at nearby locations — roads, dwellings, aviation flight paths, or rail corridors. It uses specialist software (most commonly ForgeSolar in Ireland) to model the angles at which reflected sunlight from panel surfaces could reach each receptor location.

The output is a set of glare results classified as green (low impact, generally acceptable) or yellow (higher intensity, may require mitigation). The assessment report sets out the methodology, results at each receptor, and any recommended mitigation measures.

When Is It Required?

There is no absolute legal requirement in Irish planning law for a glint and glare assessment in every case. However, in practice:

Always Required

**Ground-mounted solar farms near roads** — This is the most common trigger. If any public road is within approximately 500m of the proposed array, a glint and glare assessment will almost always be requested by the planning authority, either proactively or as Further Information.

**Sites near aviation infrastructure** — Any site within the study zones of airports, aerodromes, or instrument landing systems requires an aviation-specific glint assessment prepared in accordance with Irish Aviation Authority (IAA) guidance.

**Sites near rail corridors** — Iarnród Éireann infrastructure is a prescribed sensitive receptor. Sites within sight of railway lines should include a rail corridor glare assessment.

**An Bord Pleanála Strategic Infrastructure Development (SID) applications** — ABP applies a higher technical standard and consistently requires glint and glare assessments as part of the application pack.

Likely Required

**Commercial rooftop PV near roads** — Large commercial rooftop installations visible from public roads may require an assessment, particularly where panels face south-west and could cause afternoon glare toward road users.

**Sites near residential properties** — Where ground-mounted panels are within 300m of dwellings, most planning authorities will request evidence that glare impacts have been assessed.

**Sites in visually sensitive locations** — National Parks, Areas of Outstanding Natural Beauty, and Natura 2000 sites attract additional scrutiny, and a glint assessment may be required even for smaller installations.

May Not Be Required

**Rooftop solar on domestic dwellings** — Planning-exempt domestic solar typically does not require a glint and glare assessment unless specifically requested.

**Small commercial rooftop installations in urban areas** — Where the installation is not directly visible from roads or sensitive receptors, an assessment may not be necessary. A desktop review is advisable before deciding.

Why Submit Proactively?

Many developers ask whether they should wait and submit a glint and glare report only if the planning authority requests one as Further Information. Our strong recommendation is to submit proactively. Here is why:

A Further Information request typically adds 4–8 weeks to your planning determination timeline. In a competitive development environment, this delay can affect grid connection timelines, financial close, and project programme. Submitting proactively removes this risk at the cost of one report.

Proactive submission also signals to the planning authority that your application is technically thorough — which can positively influence how the overall application is received.

How Long Does It Take?

Our standard turnaround for a glint and glare assessment using ForgeSolar is **2–4 weeks** from receipt of complete site information (site layout drawings, panel specifications, and receptor survey). Expedited delivery in 7–10 working days is available for urgent planning submissions.

Get in Touch

If you are unsure whether your project requires a glint and glare assessment, [contact us](/contact) with your site details and we will advise you within one business day — at no charge.

See also: [Glint and Glare Analysis service](/services/glint-glare-analysis) | [Solar Glare Pre-Simulation](/solar-glare-pre-simulation)

Related Services

Glint & Glare Assessment Glint & Glare Report

Frequently Asked Questions

Is a glint and glare assessment always required for solar planning in Ireland?+

Not always, but most local authorities and An Bord Pleanála request one for ground-mounted solar farms. Even where not mandatory, submitting a glint and glare assessment proactively reduces the risk of further information requests.

What receptors are assessed in a glint and glare report?+

Assessments typically cover residential dwellings, public roads, railways, aviation flight paths, Air Traffic Control Towers, and other sensitive locations within the site's zone of theoretical visibility.

What happens if glare is predicted at a receptor?+

Where glare is predicted, the report will recommend mitigation measures — typically anti-reflective coatings, adjusted panel tilt or orientation, or screening planting — and a revised assessment is submitted.

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