Calculating large projects: Room-by-room calculation in DIALux evo

Large projects, many rooms, countless luminaires, anyone who has ever calculated a complex lighting design knows how time-consuming and memory-intensive it can be.
With very large projects, classic calculation methods often hit physical memory limits: in some cases, the project can no longer be calculated in full.

With the new room-by-room calculation, we are introducing a procedure in DIALux evo 14 that makes lighting calculations faster, more flexible, and above all more scalable.
By calculating individual rooms or areas step by step, even very large projects can be processed without issues, no need to recalculate everything from scratch.

Room-by-Room Calculation

Room-by-Room Calculation is a new calculation method that allows lighting calculations to be performed per room or per section. 

Instead of calculating the entire project at once, DIALux evo saves partial results and adds them up to a total result. 

This means you can calculate only specific rooms, selectively recalculate changes, and still display the overall result correctly. 

The process is based on an additive principle: calculated rooms retain their values while others are added later. This keeps the calculation modular and traceable.

What’s in it for me as a designer?

With the new room-by-room calculation, you gain numerous advantages in daily work:

• Save time: Recalculate only the areas that have actually changed.
• Work flexibly: Calculate and compare rooms independently of each other.
• Maintain stability: Areas that have already been calculated remain unchanged, even when work continues elsewhere. 

The familiar calculation settings also work with the new room-by-room method. Options such as “calculate direct light only” or “calculate calculation surfaces only” can still be used and will shorten calculation times even further when quick interim results or comparisons are needed. In short: less waiting, more designing and finally the ability to calculate large projects in full.

How to use the room-by-room method

The new method can soon be activated with just a few steps:

• Activation in the calculation settings:
  Open the calculation settings in DIALux evo. Where context calculation used to be activated, you will soon find the option “Room-by-room calculation.” Once enabled, DIALux evo will calculate only the currently selected room when you start the calculation, instead of the entire project.

• Calculation via context menu:
  Alternatively, in the building or room view you will soon be able to right-click a room. The context menu will include the option “Calculate room.” This lets you recalculate a single room quickly and easily, without reprocessing the rest of the project.

With these two options, controlling calculations remains flexible and intuitive. You can decide exactly which rooms to update and when.

Known conditions

The room-by-room method brings new flexibility but also changes how certain situations are handled. 
Keep these points in mind:

• Light exchange between rooms: 
  If rooms exchange light e.g., through openings or windows this light exchange is not considered. 
  Each room is calculated on its own.
• Overlapping rooms and areas: 
  If an area spans multiple rooms or rooms and areas overlap, you can calculate either the area itself or the affected rooms, not both at the same time.
  In this case, the most recently calculated result takes precedence and replaces the previous calculation.
• Geometry changes: 
  If the project geometry changes, such as moving walls, adding openings, or inserting/moving furniture, all previous calculation results become invalid.
  DIALux provides a simple function to automatically update and recalculate all previously calculated rooms. 
  This saves time and ensures results remain correct and consistent at all times.
• Display of results: 
  In the respective view (room, floor, building, or outdoor area) it is always clear which areas have already been calculated and which are still missing.

With the new room-by-room calculation, DIALux evo is taking a big step toward efficient, modular lighting design. 
The new calculation method makes large projects manageable, speeds up changes, and gives you more control in the design process. 
The familiar calculation options remain, only the flexibility is new.

The new room-by-room method will be available soon with version 14 of DIALux evo.