Roofs can provide more than just shelter. They can, for instance, generate energy, store water, lower heat stress and improve biodiversity. However, this potential is generally not used, partly because the business case appears to be challenging.

Rooftop Impact Model provides insight in the effectiveness of various rooftop types

Which rooftop solution is feasible or most suitable, depends on the setting, for instance the party involved, the surrounding location and the building itself. The Rooftop Impact Model provides insight in the underlying factors that need to be considered in deciding on the most fitting solution.

Input for the model can be submitted by entering the square meters of each rooftop type or the percentage of the total rooftop surface. Another starting point is to define a preferred target impact (e.g. X cubic meters of water storage).

The model consists of scientific information on the potential effect of a square meter of a certain rooftop type for a function. For each chosen rooftop type, the model can thus show the resulting effects for all functions. It can also show to what extent the preferred target impact is completed.

Rooftop Impact Model

Rooftop Impact Model

Planned multi-functionality for sound business cases

An advantage of rooftop adjustments is that they often encompass multiple benefits, such as improved air quality and attractive view and water buffering. Some of these benefits are a bonus, and were originally not intended by and are not directly beneficial for the investor. Purposefully planning multiple, harmonious benefits, with multiple investors, enhances the efficiency of rooftop areas and eases the creation of a business case that is attractive for all parties.

Download the Rooftop Impact Model, in an Excel spreadsheet format, here

For an extensive description of the model and the applied numbers on effectiveness, download the ACC report on “Climate Resilience and Circularity in Construction assignments” here