Categorie archief: publications

COP22 : CO2 budgets and buildings

The past week I could participate in COP22 during Buildings Day, with a presentation on the consequences of the Paris agreement for the buildings and the building sector. We have a maximum budget of 800 GT CO2 that can be emitted before the 2 degree threshold is passed, and what should the building sector do as fair share ( Around 40 % of CO2 emissions is built environment related) . Verder lezen


Housing corporation award jury

At the National Dutch congress “Sustainable built” , a award will be given to housing corporation with the most creative approach regarding climate change.  As member of the jury I was asked to give a a impression of the implications of  climatechange ambitions.  It has been published as a column on the conference website (in Dutch) :

The congress and award ceremony is 16 November.



Retrofit: Energy-saving or energy-generation?

Just published : our research into the optimal balanced materials package for 0-energy building retrofiit, ZEB . As previous exploring research already showed regarding renovation for row house: better insulate less and add some more PV panels. (B in left graph) . In other words, passivehouse is not the optimal choice from materials perspective in case of 0-energy and beyond. The operational energy in all cases is not relevant since all cases are ZEB: its the materials input that determines the most optimal solution, since that is the fossil energy based impact remaining for a ZEB. This paper shows the results for row houses and detached houses, both calculated for 4 alternative packages.

Preparation of Articles for the Symposium Report Preparation of Articles for the Symposium Report

Ritzen,M., Haagen T., Rovers R., Vroon Z., Geurts C., Environmental impact evaluation of energy saving and energy generation: Case study for two Dutch dwelling types Building and Environment, Volume 108, 1 November 2016, Pages 73–84

for some backround on the MAXergy methodology , visit

for some background on the new situation for building evaluations after eliminating operational energy impact, see Rovers R., Zero-Energy and beyond: a paradigm Shift in assessment, Buildings, 5 (1) (2014), p. 1-13


COP21 survey for Sustainable Built environments

iiSBE , the international initiative for a Sustainable Built Environment, has developed a survey to solicit views from our key members and contacts on the possible measures to reduce the impact of the built environment on climate change.

Its contributed in several ways to the COP21 meetings in Paris. iiSBE is the only independent organization addressing sustainable building, consisting of individuals, most of them related to a university or knowledge institute .

The results will be further discussed during the Sustainable Built environment conference series organized in 16 countries worldwide , coordinated by among others iiSBE .

The report can be downloaded here : iiSBE COP21 survey report 22Nov15