Volksschule – Angergasse 18

Name and address

BEST 18 |Volksschule – Angergasse 18

Map

City map highlighting the surface occupied by the demo site

Building block 1+2

Description

Within 12 weeks (mostly during summer holidays), 14 classes of the primary school Angergasse underwent a major refurbishment process. Measurements related to energy efficiency, general upgrading and accessibility have been implemented. Final work lasted until December 2016. Energy savings of 89 % (heat energy demand) were achieved.

Ownership

Innsbrucker Immobilien IIG

Gross volume: n/a

Gross surface: 3,073 m²

Treated floor area: 2050 m²

Energy performance

BEFORE

227.1 kWh/m2a (total), heat energy demand 119 kWh/m² a

TARGET/AFTER

47.1 kWh/m2a (total) heat energy demand 13 kWh/m² a

Detailed characteristics of the building

The building consists of 4 small complexes of buildings shaped like an U. Building block 1+2 in the South were part of the refurbishment.

Plot map

Detailed implantation

Building envelope

Building block 1 and 2 had different types of outer wall construction: (a) concrete (38cm), (b) reinforced concrete (20cm) plus mineral wool (3cm), (c) aerated concrete (5cm) plus reinforced concrete (25cm) and 3-layers plate (5cm) (d) or bricks (38cm). Windows had Uw between 2.5 and 3.7 on average.

Technical system

Natural gas for heating

Thermal imaging before refurbishment

Energy performance certificate

Category B

Other relevant technical aspects

Not applicable

Concept

The school was refurbished to Enerphit Passivehouse standard, including:

• Thermal insulation of walls (perimeter insulation, thermal insulation composite system (External Thermal Insulation Composite Systems (ETICS)) with 22cm EPS;
• Drainage of the basement;
• Insulation of the uppermost ceiling (35cm cellulosis);
• Installation of triple-glazing windows (Uw 0,69-0,73).

Additional measures:

• fire safety;
• accessiblity (incl. preparation of elevator shaft);
• functional improvements (daycare center, school kitchen).

Energy solutions

• PV-Installation on the roof (58kWp, around 364 m², 219 Solarwatt Blue 60P – glass-foil module);
• Hydraulic compensation of the heating adjustments
• LED-lightening systems

Performances targets

Total energy savings of about 80%

Financing model

100% public

Layout plan

• Building block 1+2
• Thermal insulation of walls (perimeter insulation, thermal insulation composite system (External Thermal Insulation Composite Systems (ETICS)) with 22cm EPS;
• Drainage of the basement;
• Insulation of the uppermost ceiling (35cm cellulosis);
• Installation of triple-glazing windows (Uw 0,69-0,73).

Envelope details

Windows

Technical system

Mechanical ventilation: 

• Comfort ventilation system with heat recovery;
• School: Pichler RG 4.4, air volume flow 8050 m³/h with 87% heat recovery;
• Kitchen: Pichler RG 2.2, air volume flow 2600 m³/h with 89% heat recovery.

Electric renewable integration:

Installation of a PV system on the roof. Characteristics are as bellow:

Nominal power: 58.035 kWp (363 m²)

Mounting type: Roof mounted parallel

Elevation: 574 m a.s.l.

Model: Power reduction for consumers

Stakeholders involved

Contracting authority

IIG - Innsbrucker Immobilien GmbH & Co KG

Project manager

DI Walter Aistleitner, IIG

Architect

DI Michael Schafferer, Architect

Technical system designer

Ingenieurbüro A3

Windows supplier

Huter&Söhne

Weithaler

Costs and financing

Refurbishment costs

4,33 M€ including general function improvements such as accessibility, after-school-care club, and lunchroom.

Financial resources

IIG, plus public subsidies for various energy efficiency measures through Austrian federal environmental support schemes and the EU.

Implementation planning

1 - Signature consortium agreement: 2015

2 - Start of refurbishments: 05-2015

3 - Completed refurbishments: 12-2016

Work progress

The main challenge was the short refurbishment time during the school summer holidays.

Photos of the building after refurbishment

Thermal imaging after refurbishment

Yearly prognosis

Total production of solar energy 2017: 59.283,33 kWh

Share of self-sufficiency: Within a test period from 1/17 to 4/17 the solar fraction has been determined and was in order of 42 percent. Surplus electricity is feeding into the public grid

Renewable energy sources

Total production of solar energy in 2017: 59.283,33 kWh
Share of self-sufficiency: Within a test period from 1/17 to 4/17 the solar fraction has been determined and was about 42%. Surplus electricity is fed into the public grid.

Energy performance certificate

Monitoring System

A public tender has been performed for purchasing the monitoring equipment, calibrating and installing them at the refurbished buildings.