Review: Vabi Daylight Ratio and Lighting

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The performance or suitability of a building design is often not known till late in the design phase. Using a suite of low-cost Revit add-ons from Vabi, it is now possible for architects to check throughout the design process. By Martyn Day

Dutch developer Vabi is perhaps better known for its domination of the building performance analysis market in the Netherlands. But in May the company launched a broad range of design-checking add-ons for Autodesk Revit, all linked to an intuitive ‘dashboard’ metering system, for instant performance feedback.

While Revit add-on applications are not new, Vabi is trialling a unique monthly low-cost subscription model for its applications, which can be turned on and off each month.

The company believes that customers should be able to download and use additional functionality when it suits their project phases. With each application offering bite-sized capabilities they are easy to learn, and utilising the dashboard provides clear feedback on just how well a design conforms to building regulations or meets the customer’s brief.

Suite of apps

Vabi is developing a range of applications that aid designers in five key areas: Financial, Comfort, Functional, Green Building and Security/Safety. Each application is initially available on a 15- to 30-day free trial followed by a monthly price of $10 to $30.

While Vabi can call on four decades of research for building performance analysis it also offers a range of applications which are extremely useful to architects to increase productivity and spot design errors or omissions at each stage of the design process.

Daylight ratio evaluator

Just how well lit is each room in a design — either by sunlight or internal lighting systems? It is a common problem that is initially assessed by a designer’s experience, and rule of thumb, but after analysis, may require changes to a design further down the process. Vabi’s second generation Daylight Ratio Evaluator takes all the relevant information from Revit to provide a room by room assessment on the ratio of daylight to room area.


Vabi’s DRE runs a ray trace analysis of each room, to first define boundaries, find windows and glazing areas and compare the window to the floor area.

Extracting information from the model, reports are generated providing room number/name, floor area, glazing area, and the resulting daylight area. By selecting the lists in the report the respective Revit element is highlighted, so it is quick to edit failing rooms. On a reasonable Revit workstation, results for 1,000 rooms can be generated after about two minutes of processing. After the analysis the performance indicator is displayed in the dashboard, showing the percentage compliance of the whole design to the specified daylight ratio.

Lighting organiser

Coming soon, Vabi’s Lighting Organiser provides additional analysis to Revit MEP. Essentially the application checks each designated space for the number of lights and can assess if these spaces meet the specified lux levels, which can vary from room to room.

The software gives feedback on average luminance, lighting comfort level and electricity use.

It is designed to help architects pick the most efficient lighting strategies while meeting their lighting requirements. The analysis does not take into account material reflectance. Again the results are displayed in the Dashboard for a ‘quick look’ performance guide.


Two applications provide essential feedback on both daylight and artificial lighting, ensuring the glazing area meets requirements and the lux levels are met on a room by room basis while being the most energy efficient.

Since Vabi launched its suite of apps it is clear that its product line is rapidly developing beyond performance analysis, to offer architects additional capabilities to Revit. Feedback from customers is also helping to improve each application, and the lighting apps have been specifically in demand.

Subscription, while popular among Autodesk and Adobe, is relatively new to third party applications and here the low-cost of Vabi’s apps is also a new concept, especially acknowledging that customers are in control of switching them on and off, like lights.

Price: $9.99 a month

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