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"How do we obtain the best level of energy efficiency in a 100-year-old building? And how can we pave the way for future energy renovations?" These questions led to the first energy renovation in Holland that transformed a historical building into a passive house according to the Passivhaus Institut in Darmstadt in Germany.

*(ro-en) project_rw_responsible*

Industrieweg 15
NL-6045 JG Roermond
The Netherlands

Phone: +31 475 353 035


*(ro-en) project_developer*

Woonstad Rotterdam

*(ro-en) project_contractor*

BAM Woningbouw

*(ro-en) project_architect*

Villa Nova Architecten

*(ro-en) project_consultancy*


Award winning investment
In 2009, the building block from 1903 on Sleephellingstraat in Rotterdam was transformed into fourteen unique apartments for sale, raising the value of the building significantly.

Sleephellingstraat is one of the best attempts at lowering energy consumption to meet the Passive House Standard in this building type and was the first in the Netherlands to receive the PassiefBouwen Award in 2009 and was nominated for The Golden Phoenix 2011 and The Dutch Building Award.

Renovation behind the facade
"The historic building falls under the historic preservation regulations. The nature of the building and the location in the old town required an approach that would maintain the unique character of the building," explains architect Andries Laane from VILLANOVA Architechten.

To preserve the original façade and at the same time raise the energy efficiency level to a passive house standard, the insulation was integrated on the inside of the building, leaving the exterior untouched.

"ROCKWOOL® insulation is very easy to work with. It is easy to adapt to variations in construction and size. This makes it perfect for renovating old buildings where unforeseen challenges often arise,"the architect says.

The obvious choice
Choosing the passive house model as a renovation method was not an obvious choice for the old building.

"The main reason to choose the passive house principle was to increase living comfort and to cut energy consumption level as much as possible. Since the passive principles provide a constant indoor climate in both summer and winter and create a more comfortable and healthy indoor environment, it seemed like a good idea to try the principle in the Sleephellingstraat building,"saysAgnes Schuurmans, who works with regulations, codes and standards at ROCKWOOL International.

A survey conducted in 2011 by Woonstad Rotterdam, BAM Woningsbound and Ferroli shows that the residents are happy with living in the Sleephelling building. The apartments live up to their expectations, e.g. by having a comfortable indoor climate both during cold winters and hot summers.

A beacon for the future
The passive house principle based on super insulation and a high degree of airtightness of the building shell keeps future maintenance to a minimum while providing significant energy savings.

The renovation reduced the energy consumption level to 27% compared to an Energy Class A house.  Residents pay no more than 10 Euros per month for heating. That is 15% of the heating cost of an average newly built house in the Netherlands.

"The renovation of these historical buildings into low energy standard houses clearly demonstrates that all types of structures can be turned into energy-efficient buildings," says Peter van der Have, BAM Woningbouw Rotterdam and Agnes Schuurmans, ROCKWOOL International.