How to Choose a Lighting Consultant
Lighting is judged after handover, when changing it is expensive. The choice of consultant decides whether the result was calculated or hoped for.
Lighting design is a multi-disciplinary field. It calls for knowledge of physics and optics, electrical engineering, ergonomics and the physiology of vision, together with codes, environmental requirements and construction technology — and the design craft to reconcile them.
EN 12464-1 derives its requirements from three human needs: visual comfort, visual performance and safety. Its 2021 edition also accounts for the non-visual effects of light on well-being and performance.
The consultant reconciles those layers into one set of decisions: which values govern, at what energy cost, in what relation to structure and services, and in service of what architectural intent. It is a design and analysis service, upstream of supply and not the same thing as it.
That distinction has commercial consequences. A specification written by the party that also sells the equipment tends to grow toward its own catalogue. Separating advice from supply keeps the specification proportional to the project.
Lighting is calculated, not sketched.Photometry before rendering · the model before the mood board
What good looks like.
Eight points that separate proposals which look comparable on paper.
The work happens in the model, not beside it. Luminaires are placed in Revit as families carrying photometric data, so position, mounting height, type code and count are read from the model rather than maintained in a parallel spreadsheet that quietly stops matching.
Calculation native to the model. This is the sharpest technical question you can ask. DIALux and Relux are capable tools, but the usual workflow exports geometry, calculates elsewhere and brings results back — and every export is a moment where the calculation and the building can drift apart. ElumTools calculates point-by-point illuminance inside Revit, on the same families, geometry and surface materials the model already holds, and returns a radiosity view of the result. A consultant fluent in both approaches can match the tool to the project instead of forcing every project through one.
Clash detection that includes light, not only bodies. Two different checks. The first is geometric: luminaire against duct, sprinkler, structure, ceiling grid, and access for maintenance. The second is beam obstruction — a beam or a duct that registers no geometric clash at all can still take half the light off the surface it was aimed at. The second check is the one usually missing.
Photometrically honest visualisation. A render should be produced from the same photometric data as the calculation, so that what the client approves is what the calculation predicts. An image assembled from a daylight photograph with light painted on afterwards is a sketch of an intention, not a prediction of a result.
Survey capability for existing buildings. In revitalisation the model does not exist yet, and the drawings rarely describe what was actually built. Laser scanning and photogrammetry, processed through ReCap into a point cloud and then into a Revit model, give a base that matches the building as it stands — including the voids, beams and services that decide where a luminaire can physically go.
Standards named, not implied. EN 12464-1 for indoor work places, EN 12464-2 for outdoor work places, and the metrics that come with them: maintained illuminance, uniformity, colour rendering and glare rating. A consultant should say which standard governs this project and what target values apply, before anything is modelled.
Data that survives handover. Luminaire schedules extracted from the model, placement plans, quantities and an as-built model reconciled with what was actually installed — not a folder of drawings that stopped matching the building on the day it was issued.
Independence from supply. Worth writing into the enquiry as a separate line.
Questions to ask before you appoint.
Eight questions that separate advice from supply within one meeting.
- Will lighting be modelled in Revit, or documented separately in CAD?
- Do you calculate natively in the model with ElumTools, or export to DIALux or Relux — and why that choice for this project?
- Which standard will the scheme be calculated against, and what target values apply?
- How do you check beam obstruction as distinct from geometric clash?
- Are visualisations produced from the calculated photometric data, or composed separately?
- For an existing building, how is the base model produced — laser scan, photogrammetry, ReCap?
- What happens to the data at handover: schedules, circuits, as-built model?
- Do you supply the luminaires you specify?
What to avoid.
Signals that the proposal is a picture rather than a prediction.
- Visualisation without calculation. A convincing night render with no illuminance report behind it. The most common one, and the easiest to check.
- Image editing used as the simulation tool. Light painted onto a photograph in Photoshop. It sells the meeting and predicts nothing about the built result.
- Calculation performed once, at the end. Photometry used to confirm a decision already taken, rather than to shape it while changing it is still cheap.
- No model, only PDFs. Lighting documented outside the project model drifts from the building and reappears as site queries.
- Clash checked on bodies only, with no test of whether the light actually reaches the surface.
- The consultant is also the supplier.
- Standards invoked generically — “compliant with European norms” — without naming which standard and which values.
- In revitalisation: designing on the old drawings. Existing buildings are not what their drawings say they are.
How Lucid approaches it.
What the above looks like in practice.
The workflow is BIM-first and structured on ISO 19650. Luminaires live in the model as Revit families with photometry attached, carrying a type code, mounting, finish, status and revision as shared parameters, so schedules and placement plans are generated from the model rather than maintained beside it.
Calculation runs natively in Revit with ElumTools where the project benefits from staying inside the model, and in DIALux or Relux where the scheme calls for it. Illuminance, uniformity, colour rendering and glare are checked against the standard agreed at the outset; for exterior schemes, so is light spilling beyond the target area.
Coordination covers ducts, sprinklers, structure, ceiling grid, cable routes and maintenance access, and separately the obstruction of the beam itself. Issues are raised and tracked as BCF, with an owner, rather than as screenshots in an email thread.
For existing buildings and revitalisation, the base is produced by laser scanning and photogrammetry, processed through ReCap into a point cloud and modelled in Revit — so the design is made against the building that stands, not the building that was drawn.
Visualisations are produced from the calculated data, not composed separately, so the image and the report describe the same scheme.
Where a manufacturer provides no BIM family for a specified luminaire, we model that family from scratch — from the datasheet and the photometric file — so the model stays complete and every luminaire appears in the schedules. Lucid is an independent consultancy and does not supply luminaires.
Frequently asked.
What does a lighting consultant actually do?
Carries a lighting scheme from criteria to documentation: establishes which requirements govern and at what values, proves the solution by photometric calculation, coordinates it against architecture, structure and services, and documents it so it can be built. It calls at once for knowledge of physics and optics, ergonomics, codes and energy accounting, and for the craft to reconcile them. It is a design and analysis service, upstream of supply and independent of it.
Why does it matter whether lighting is calculated inside the BIM model?
Because every export is a chance for the calculation and the building to drift apart. Calculating inside Revit uses the geometry, families and surface materials the model already holds, so the result reflects the current design rather than a snapshot taken weeks earlier. External tools remain useful, but the round trip has to be managed deliberately.
Can a lighting visualisation be trusted?
Only if it comes from the same photometric data as the calculation. An image built by painting light onto a photograph communicates an intention and predicts nothing. Ask whether the render and the illuminance report describe the same scheme.
How is an existing building surveyed for a lighting project?
By laser scanning or photogrammetry, processed through ReCap into a point cloud and then modelled in Revit. Existing buildings rarely match their drawings, and in lighting the discrepancies that matter are exactly the ones drawings omit: ceiling voids, beams, ducts and the real positions of surfaces the light has to reach.
Related guides.
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