Green Formula

GDF - green density factor and
GCF - green cooling factor

A specific calculation method to integrate green roofs, green
facades and their evapotranspiration cooling rate into the
general planning procedure of architects and planners

See the GREEN FORMULA – by Climate Architect Dr. Ing. Betzler

The Green Density Factor and Green Cooling Factor will address architects (since roofs and façade surfaces will be affected), developers/planners (detailed decisions based on the predictions) and decision makers (politicians) – as well as a variety of specialists working in the fields of water management, city climate and sustainability. The factors allow to adjust/optimize the entire building regarding its shape, the energy systems and the exterior greenery towards environmental buildings and cities. Furthermore, the factors will allow cities to set guidelines for upcoming construction projects using these factors to set the cooling capacity and/or the amount of greenery which has to be used in order to ensure a cool and sustainable climate surrounding.

Using this approach, architects and city planners are able at a very early stage to include it into a life-cycle-assessment of the building and increase its value through the benefits of the exterior greenery such as the cooling capacity as well as contribute towards a beautiful place to live in.

Green Density Factor (GDF)

The GDF relates the amount of exterior greenery on façades and roofs to the paved footprint of the building. The more exterior areas are vegetated the higher the GDF. Following this approach, the negative effects on the city climate as a result of paved areas can be (over)compensated by exterior vegetation, including other positive consequences that follow. It should be noted, however, that there are other negative effects resulting from paved city surfaces (e.g. on the soil and ground water) that can be partly recovered by vegetated buildings regarding the two factors.

Green Cooling Factor (GCF)

Based on the GDF, the Green Cooling Factor (GCF) will allow to calculate the cooling impact of the building vegetation into the city micro climate. The cooling effect is a result of evapotranspiration of the plants. The cooling capacity measured in Kilo-Watt-hour (kWh) per year will be compared to the building energy used in heating, ventilation and air condition (HVAC), as well as the electrical components of the building installation. Both will be measured against each other, in order to overcompensate the heating of the environment.




Let us develop your sustainable urban environment

It would be our honour to support your need for a healthy and sustainable real estate developments.

For Developers and Architects


  • Increase of building value
  • Decrease of running costs
  • Faster amortisation
  • Able to use a tool to plan green buildings


  • Conceptual design for specific Developments, law AND CODING PROCESSES
  • Certification for sustainable real estate and greenery

For Universities and Conventions


  • Opportunity to create green environments
  • Change the legal framework in ordert o implement a green factor
  • The chance to developed green and healthy urban environments


  • Teachings and presentations for universities and companies
  • Building the City of the future
  • Calculation of the Green Cooling Factor and the Green Density Factor including amortisation and economical gain

For Administration and politics


  • Ability to decrease costs of site development by transfering obejctive to private sector


  • Teaching the possibility to reduce infrastructural costs through climate architecture
  • Applying the GDF/GCF to regional habitats and cities
  • Workshops, planning the city of tomorrow
  • Let us start and join our green revolution now!

We would be happy to provide our wide assortment of services to you, your company as well as public institutions. There are many great ideas within the market, however we have the ability to quantify the effects and make them measurable to utilize the full capacity out of your development. This formula is usable in any scale, from a standard family house to a whole city.