Case Study: nZEC - Energy refurbishment of 49 dwellings in Schultheißallee, Nürnberg, Germany
Name of organisation: WBG - Nürnberg GmbH Immobilienunternehmen
Stage of development: completed
Year of finalization: 2012
Type of project: refurbishment
Area: urban
Scale: individual buildings
Type of building: Apartment in a block of six to ten stories
Number of units/dwellings: 49
Tenure: social rental
Street: Schultheißallee, 34
Postcode: 90473
City: Nürnberg
Region/ County: Bavaria
Country: Germany
Last Update: 14.04.2015
Short Description
The 1964 constructed residential building in the Schultheißallee with 49 dwellings has been refurbished in the scope of the 4th project phase of the German Energy Agency (dena) model project "Low-energy house model for existing buildings".
- Insulation of outside walls, pedestal body and roof, replacement of the windows, improvement of fire protection in important areas.
- Removal of the old reinforced concrete balcony construction, installation of pre-set steel balconies.
- Removal of the window parapets and installation of passive house windows for the access to the balcony. Thereby improvement of the living.
- Refurbishment with passive house components consequently avoiding thermal bridges. All construction works have been done in inhabited condition.
- New installation of transfer station of the existing district heating, insulation of the heating cable according to Energy Saving Ordonance .
- All bathrooms were connected to the hotwater heating system, new groundworks. Installation of a controlled ventilation system under further use of the existing ventilation lines.
- The thermal solar installation with tube collectors on the roof contributes to high solar coverage of the warm water needs.
Key Elements
Certification
- Annual primary energy requirement QP=12,9 kWh/(m²a)
- Specific transmission heat loss HT´=0,26 W/(m²K)
- Annual final energy requirement Qe=34,7 kWh/(m²a)
- HT´ 52% better compared to Energy Saving Ordonance
- QP 24% better compared to Energy Saving Ordonance
Work with Residents
Refurbishment while being occupied. Special challenge for planning, construction management and construction companies.
Funding
Partly KfW financed, DENA model project "Low-energy house model for existing buildings.
Thermal Insulation
Outside wall ETICS with 20 cm EPS insulation U = 0.15W/(m2K), Insulation of basement ceiling 16 cm EPS with flanking insulation of inside and outside walls. Outside basement wall perimeter insulation with 20 cm XPS insulation until 1 m under the surface. Insulation for roofs: replacement of the wooden rafter roof by EPS tapered insulation U = 0.10W/(m2K).
Air Tightness
Foil sealing, insulated attic cantilever with external channel. Installation of controlled exhaust system with fans on the roof surface, ventilation window opening.
Windows and Shading
Passive house windows Uw 0.71 with triple glazing Ug = 0,50, G-value 51% - Wooden fireproof glazing in the stairwell with F30 glass.
Ventilation
Exhaust air system with heat recovery.
Heating and Hot Water
Central heating with district heat (88 % cogeneration). New installation of hot water distribution in all bathrooms while being inhabited. Distribution of warm water and heating in separate trains with insulation according to Energy Saving Ordonance. Replacement of the old gas boilers one apartment after another, transfer station with calorimeter and fire resistant collar for each apartment. Hydraulic balance. Thermal solar installation with tube collectors on the roof surface for support of hot water production.
Solar Thermal
Thermal solar installation with tube collectors on the roof surface for hot water production.
Main Results
Lessons learned
Additional Information
Ms Ingrid Vogler
GdW Bundesverband deutscher Wohnungs-und Immobilienunternehmen e.V.
E-mail: vogler@gdw.de
Web: www.gdw.de