Human-Centric Lighting Research &amp; Design Guides

LEED v5 EQc2 Option 5: The Lighting Data a Submission Has to Carry

LEED v5 EQc2 Option 5 asks for luminance under 6,000 cd/m² or UGR 19, plus CRI 90 or TM-30 values. The data each test needs, and what the text leaves open.

Daytime Light Averages 75 lx Melanopic EDI: What Field Measurements Show, and What a Specification Can Do

A nine-site study found 24.0% of daytime minutes reached 250 lx melanopic EDI. What the measurements show, how 75 lx is misread, and five spec clauses.

27 min read

Hong Kong BEEO Stage Two: The Lighting Numbers Building Owners Must Audit, Disclose and Defend from 20 September 2026

The second stage of Hong Kong's Building Energy Efficiency (Amendment) Ordinance 2025 took effect on 20 September 2026. The audited building list grew from 2 types to 11, the audit interval halved to five years, and Form EE-D now publishes two lighting numbers as a percentage of lighting area coverage: lamp type mix and automatic lighting demand control. This article sets out what to measure before the audit window opens.

ISO/CIE 8995-1:2025: When Workplace Lighting Standards Adopt Melanopic EDI

ISO/CIE 8995-1:2025 puts melanopic EDI into workplace lighting. What its public record shows, what it does not, and the data to demand from suppliers.

Jewellery Lighting: CRI 97, TM-30 Rf/Rg & Colour Shift Δu′v′

CRI 97 measures eight colour samples and says nothing about R9, nothing about the spectrum after two years on a case. A supplier-facing specification guide to Rf, Rg, Rcs,h1 and the two colour-shift statements a jewellery counter needs.

31 min read

WELL v2 Lighting Requirements: A Supplier Checklist

Two preconditions, seven optimizations, eighteen points — and only three features closed out by a measurement in the space. A document-by-document checklist of what a WELL v2 lighting project must produce.

26 min read

Tunable White 2700K–5000K: Office Daylight Curves

An office daylight curve is a schedule, not a colour mode. How to set the 2700K–5000K band, anchor nodes to solar noon in Hong Kong, keep ramps below detection, and specify Duv.

Research & Evidence

13 min read

Flicker-Free Specification: Why SVM Matters

"Flicker-free" is not a number. This guide explains SVM (stroboscopic visibility measure), the EU's 0.4 limit, and the clause to write into a lighting specification.

13 min read

Circadian Lighting Singapore vs Hong Kong: What Changes in the Spec

A market-by-market spec guide: what stays identical and what must change when a circadian lighting program moves between Singapore and Hong Kong.

8 min read

Boutique Retail Lighting: Time-Spectrum Programs & Dwell Time

A practical guide to time-spectrum lighting for boutique retail — the schedule, the evidence, and how to extend dwell time with a deployable program.

8 min read

Human-Centric Lighting Hong Kong: The Complete Office Guide

A practical guide to human-centric office lighting in Hong Kong — productivity evidence, WELL alignment, and a ready-to-deploy tunable white schedule.

16 min read

The SME Office HCL Retrofit Guide: Better Light, No Rewiring

A practical guide for SME office owners: how to upgrade an existing 100–500 sqm office to human-centric lighting using wireless Matter drivers — no rewiring, no structural changes, measurable results from week one.

13 min read

One App, Every Light: The LTECH Smart Life Ecosystem Explained

One gateway, one app, up to 300 devices. Here is how LTECH Smart Life connects your entire HCL lighting system — from the wall panel to your phone — without a dedicated server or IT setup.

Research & Evidence

20 min read

The M/P Ratio: The One Number That Separates Real HCL From Expensive Marketing

Every supplier now claims human-centric lighting. The M/P ratio is the single parameter that separates a calibrated circadian system from a rebrand. A specifier's guide to what it measures and how to require it.

Research & Evidence

14 min read

Why M/P Ratio Is the Metric That Matters

Most lighting designers still specify by lux and CCT. Here is why the melanopic-to-photopic ratio is the single number that determines whether a space supports or disrupts circadian health.