Lighting design software: the lux a room will actually get, and a report to prove it
Lighting design software exists because a fitting's wattage says nothing about how much light lands on the desk. CivilOS's Lighting & Lux calculates it properly: direct light point by point from each fitting's photometric table, plus the light reflected off the floor, ceiling and walls by radiosity — with each surface's reflectance taken from the colour it is actually painted. The average lux, uniformity, glare rating and power density are read on the grid EN 12464-1 lays down.
It lives in Interior Studio, so the rooms are the rooms you have already drawn. One click lights every room to its target with the fewest watts; then you move, add, dim or swap fittings and the table updates live. Load the maker's IES or LDT file and the calculation uses the real product. A printable lux report with false-colour plans is one more click.
What you can do
| Feature | What it does | Export / status |
|---|---|---|
| Direct light | Point-by-point from photometric tables; large fittings split by the five-times rule | Report |
| Reflected light | Radiosity over floor, ceiling and walls; reflectance from the painted colour | Report |
| Results | Average, minimum and maximum lux, U0, Ud, UGR, power density, daylight factor | Report |
| Targets | Per room type from EN 12464-1, IS 3646 and NBC 2016 Part 8 | — |
| Photometric files | IES (LM-63) and EULUMDAT (.ldt) read into the same calculation | — |
| Auto-design | Every room lit to standard with the fewest watts across candidate fittings | — |
| Lux report | False-colour plans, isolux lines, values and the fittings schedule |
Numbers you can check
Every figure the panel shows comes from one calculation, at the same resolution on screen and in the report, so the number on the client's copy is the number you saw. The calculation is tested against closed-form answers, and the photometric tables are checked to integrate to exactly the lumens on the label.
The simplifications, stated
Furniture is not treated as an obstruction, light through an opening from the next room is not counted, and generic fittings are textbook distributions until a manufacturer's file is loaded. Those are the simplifications a first-pass room in any lighting program makes, and the report says so rather than leaving the reader to assume otherwise.
How to start
- Open Interior Studio with your plan, and open Lighting & Lux.
- Light every room to standard — or place fittings yourself on the plan or in 3D.
- Read the table: lux, uniformity and glare against each room's target.
- Load the maker's IES or LDT file for the product you will specify.
- Print the lux report for the client or the authority.
What CivilOS does not do
- No annual daylight simulation and no sun-through-window study in the lux figures.
- No emergency lighting design to EN 1838.
- No photo-real rendering. The 3D view shows the lights; it is not a render engine.
- Furniture does not obstruct the light in the calculation.
- A design for checking. A lighting designer or electrical engineer signs off the final scheme.
Where a browser tool fits
Dedicated lighting suites earn their place on stadiums, façades, road lighting to standard and large daylight studies, with manufacturers' full catalogues built in.
The interior designer checking a living room, the architect confirming an office floor meets 500 lux, the electrical contractor choosing between two panels — for them a calculation inside the plan they already drew, with a report in one click, is the faster tool.
Open Interior Studio free → Lighting & Lux → light every room to standardFrequently asked questions
What does lighting design software calculate?
How much light reaches the working plane of a room — the illuminance in lux — from the fittings you place, and whether it is enough and even enough: the maintained average, the minimum, the uniformity ratio, the glare rating and the power used. CivilOS calculates all of these for every room and prints them in a report.
Is it free?
Yes, to start. Create a free account (no card) and the Free plan opens every module, including Lighting & Lux in Interior Studio, with a monthly allowance; prints carry the CivilOS letterhead. Pro, Max and Enterprise Seats plans add more hours and generations and put your own letterhead on every print. The Training Corner, Knowledge Library and Feedback are free without limit.
How is the lux calculated?
In two parts, the way a lighting engineer's calculation does it. Direct light is summed point by point from each fitting's intensity table, E = Σ I(γ,C)·cos θ / d², with large fittings split into smaller sources. Light off the floor, ceiling and walls is added by radiosity, with each surface's reflectance taken from the colour it is painted. The results are evaluated on the grid EN 12464-1 lays down.
Can I use a manufacturer's photometric file?
Yes. Load the IES (LM-63) or EULUMDAT (.ldt) file of the actual product and the room is calculated with its real distribution. Until then the generic fittings use textbook distributions normalised to their rated lumens.
Is it a DIALux replacement?
For the first-pass design of rooms, it makes the same simplifications a first DIALux room makes: furniture does not obstruct, and light through an opening from the next room is not counted. It does not do daylight simulation through windows over a year, emergency lighting design or photo-real rendering.
Do I need to install anything or create an account?
No installation: CivilOS opens in an ordinary browser on a laptop, tablet or phone and can be installed as an app from the sidebar. A free account is needed to open the engineering modules; it takes a minute and asks for no card.
Draft for checking. Every safety-critical output of CivilOS is a preparation document. Drawings, quantities, rates, programmes and inspections must be verified, and the result signed off, by a licensed professional before they are issued, tendered, built or paid against.