Case Study: nZEC - Energy refurbishment of 129 dwellings in Tirschenreuter Ring, Berlin, Germany

Short Description

The aim of the project was a living world-oriented, comprehensive refurbishment of the building.

The main technical objectives of comprehensive energy-related modernisation were:

1. significant reduction of energy consumption and thus the warm operating costs, in minimum the halving of the energy consumption in residential buildings
2. the implementation of a life-world-oriented concept of the facade and the equipment of the bathrooms
3. the significant reduction of the current maintenance costs, here at least a halve maintenance costs is aimed
4. the appreciation of residential buildings by considering of barrier-poor measures, in particular in the design of the building entrances
5. the sustainability of technical measures, i.e. qualitative implementation of all construction work to realize of a defect-free life cycle process of the components of the building by at least 30 years.

The individual measures were:

- the facade renovation in accordance with Energy Saving Ordonance 2009, as heat insulation system is insulated with a colour design on the basis of the life world concept
- window replacement
- roof and basement ceiling insulation
- use of smart meters
- supplement of the district heating plant by 2 CHP to cover the base demand (1 CHP natural gas, 1 CHP biogas)
- closing of the waste discharge system to ensure an ecological waste separation and reduction of cold operating costs
- complete renovation of the water installation

The construction amounted to 13 months (02.07.2012-31.07.2013). The tenants were informed during a renovation in the inhabited State about the nature and scope of the work (tenant meeting, modernization announcement, contact during the construction period). It was promoted by the KfW-bank.

Key Elements

Certification

The energy objectives were: Primary energy consumption better than a new building (Energy Saving Ordinance) and Final energy demand between a new apartment building and a new single-family building.

Project Management

technical inventory for each apartment, construction material investigations, pollutant studies.

Work with Residents

Tenant meetings with presentation of energy-related measures. Modernization-accompanying events (Festival of tenants, sports, etc.)

If the building shell is generally airtight following to modernisation, particular attention must be paid to the ventilation of the building. Tenants get an instruction manual for their apartment, with several issues, for example proper ventilation (prevention of mold growth).

Environmental Design

Closure of waste disposal systems, since no correct separation of waste was ensured through the shafts. Creating garbage dumps with waste separation outdoors. Local district heating by two CHP (one CHP with biogas), primary energy factor of 0.39.

Funding

Financing carried by a KfW loan (program title: energy efficient refurbishment).

Thermal Insulation

Conventional thermal insulation materials (mineral wool insulation WLG 035), minimization of thermal bridges.

Air Tightness

Installation of new airtight windows  with defined openings for the ventilation of apartments, Central fan vent on the roof.

Windows and Shading

Double glazed windows with Uw = 1.3 W / m² K, no shading.

Ventilation

mechanical ventilation, ventilation of bathrooms by a central fan on the roof, back flow of air through defined openings in the windows.

Heating and Hot Water

Local heating, base load coverage with CHP, one CHP plant is powered by biogas.

Other Renewables

One CHP plant is powered by biogas.

Electricity Saving Products

Energy-saving lamps in the entrance,  staircase and corridors as well as in the basement (public areas).

Water Saving

Water-saving taps.

Main Results

Measured energy use:

Lessons learned

Development of conceptual basis for marketing and communication before, during and after the renovation:

• Cross-generational living in the country
• New name: Mariengrün
• Regular Newsletter (modernisation newsletter)
• Press tours
• Rental campaign, marketing
• Integration of the tenants, foto-shooting
• Facade banner and large posters

Development and implementation of the relocation and new letting concepts:

• Dwellings in residential buildings already completed are offered to tenants for permanent relocation or furnished dwellings for temporary relocation during the construction period.
• Attracting new tenants, care of new tenants before, during and after the construction period

Development and implementation of short-term, mid-term, long-term measures to stabilize the neighbourhood, image change of the district and stabilization and/or improvement in the tenant structure. Central fields of activity:

• Participation of tenants
• Communication
• Cooperation
• Service
  
  
  

Additional Information

Ms Ingrid Vogler
GdW Bundesverband deutscher Wohnungs-und Immobilienunternehmen e.V.
E-mail: vogler@gdw.de
Web: www.gdw.de