Glint and Glare Assessments

Glint and Glare Assessments

Independent glint and glare assessments for solar PV schemes, rooftop solar, building façades and other reflective developments.

Glint and glare can become a planning, safeguarding or stakeholder issue where reflected sunlight has the potential to affect aviation activity, road users, rail operations, nearby homes or other sensitive receptors.

Modaxis provides clear, proportionate glint and glare assessments to help developers, planners and project teams understand potential reflection effects, support planning submissions and respond to consultee concerns.

A well-scoped assessment can help identify risks early, inform design decisions and provide technical evidence where a planning authority, airport, highway authority, rail operator or local stakeholder has requested further information.

When a glint and glare assessment may be needed

A glint and glare assessment may be required where a development includes solar panels, reflective glazing, building façades or other surfaces capable of reflecting sunlight towards sensitive receptors.

Assessments are commonly requested where a project is located near aviation, transport or residential receptors. Typical screening distances include:

• Licensed airports and aerodromes, where solar PV or reflective development is located within approximately 10 km

• Unlicensed airfields, where development is located within approximately 5 km

• Roads and residential properties, where receptors are located within approximately 1 km

• Railway infrastructure, where a development is located close to a railway line, typically within approximately 100 to 200 m

These distances are used as a practical starting point. The need for assessment may also depend on the scale and design of the development, the sensitivity of nearby receptors, local topography, visibility, stakeholder requirements and whether a planning authority, airport, highway authority, rail operator or local stakeholder has raised specific concerns.

Assessments are commonly requested for:

• Ground-mounted solar PV developments

• Rooftop solar schemes

• Buildings with reflective façades or glazing

• Developments near airports, aerodromes or aviation activity

• Sites close to roads, railways or residential properties

• Projects where consultees have raised glare, safety or amenity concerns.

Receptors considered

The right receptor scope depends on the site context, development type and stakeholder requirements. Modaxis can consider:

• Aviation receptors, including air traffic control towers, runway approaches, visual circuits, helipads, where the key concern is aviation safety and the intensity of any predicted glare.

• Road users, where the key concern is road safety, particularly where reflections may appear within a driver’s main field of view.

• Railway receptors, including train drivers, signals and other operational railway infrastructure, where the key concern is rail safety, including whether glare may occur within a train driver’s view and whether relevant signals or infrastructure are present.

• Residential receptors, where the key concern is residential amenity, including the duration of predicted effects and whether these exceed relevant daily or annual thresholds.

• Other sensitive receptors, where project-specific concerns have been raised.

What Modaxis can provide

Modaxis can support projects with:

• Early-stage glint and glare risk screening

• Solar PV glint and glare assessments

• Rooftop solar assessments

• Building and façade glare assessments

• Aviation, road, rail and residential receptor review

• Technical modelling and results interpretation

• Figures and clear visual outputs

• Review of receptor visibility

• Mitigation advice where glare risk is identified

• Changes to layout geometry to reduce effects

• Planning-ready reports, technical notes and stakeholder responses

Technical approach

Modaxis predominantly uses ForgeSolar software, based on Sandia National Laboratories’ Solar Glare Hazard Analysis Tool, SGHAT, alongside recognised solar reflection assessment principles and project-specific technical interpretation.

The assessment identifies when solar reflections are geometrically possible and whether they may be visible from relevant receptors. Modelling can consider the position of the sun, the location and orientation of reflective surfaces, receptor locations, viewing heights, terrain, timing, duration and the location of the reflecting area.

The assessment approach is tailored to the receptor type. For aviation receptors, the intensity and location of any predicted glare are key considerations. For roads, the assessment considers whether reflections may occur within a driver’s main field of view. For railway receptors, the assessment considers the potential effect on train drivers and, where relevant, the presence and visibility of railway signals or other operational infrastructure. For residential receptors, the assessment considers the duration of predicted effects against relevant daily and annual thresholds.

The specific glare scenario is then considered on a case-by-case basis, including factors such as receptor sensitivity, distance, sun position, existing screening, proposed screening, stakeholder requirements and the surrounding site context.

Where aviation receptors are relevant, the assessment can also consider relevant stakeholder-specific requirements where appropriate.

The aim is to provide clear, practical and proportionate reporting that explains the results in planning terms and helps project teams understand whether mitigation, design refinement or further consultation may be required.

Mitigation and design advice

Where potential glare effects are identified, Modaxis can provide practical advice to help reduce risk. This may include layout refinement, changes to panel orientation, targeted screening, façade design considerations or other project-specific mitigation measures.

The focus is on helping clients address genuine technical risk while avoiding unnecessary redesign where effects are unlikely to be significant.

Discuss your glint and glare requirements

Send over your site plan, layout, receptor concerns or stakeholder comments and Modaxis can advise on the right level of glint and glare support for your project.