WG1 review of urban IA studies. Case Linz

WG1 review of urban IA studies. Case Linz
                               Gerald Leindecker. IAPL

Plan of Urban Sustainability Indicators

   1. Scope of study
Context of the studies:

The study was set up to monitor the example of a new town development in Linz
(Solar City) It is a part of a comprehensive planning exercise, started in 1999 of
creating a low carbon environment in a new planning area.

The city planning lay out was done according to solar principles. Building design and
the used of material was planned according to thermal principles and to minimize
running costs. Solar City was designed as new urban development for approximately
5000 inhabitants in close proximity to the regional capital of Linz. All buildings were
done according to low energy standards and some housing units were duplicated in
passive house standard as well. The idea of a living lab was introduced to measure
and monitor the performance of buildings. The start for realization was also based on
an agreement of the 12 social housing companies involved to have common
standards in energy figures such as hot water solar panels and prime energy figure of
below 44 kWH/ (m2a). This energy performance figure was also applied towards
public buildings (schools, kindergartens and similar facilities).

                                          Picture 1: Arial Picture: Solar City (picture: Stadt Linz)

Driving parameters:
An estimated 12,000 persons were looking for apartments in Linz at that time. A
further aspect was the fact that Linz, with a population of 200,000, was the location of
nearly 178,000 jobs1.

What are the questions which these projects address?

       -   Is it possible to achieve an integrated city planning model and carry it into
           reality in a realistic time span?
       -   What are the deviations of the planned figures versus the actual measured
           figures?

What is modelled?

The evaluation within the scope of a federal research program “Building of
Tomorrow” was developed by the City of Linz to evaluate urban development
schemes with the name: “LES-LINZ Developes City).

A catalogue of target criteria for sustainable urban development was designed and
can be applied also to evaluate large construction projects.

Aspects of sustainable urban development are combined with social aspects, energy
performance and related economic factors, and also mobility issues.

One of the key elements of the evaluation tool was the requirement to be easy
useable within a city administration structure.

Various variables are projected (alternative scenarios are built especially for material
use and construction methods:

       -   Land use:
             o Avoid further urban sprawl and have a controlled expansion of the city

       -   Population growth and household average size evolution
             o Total population scenarios and one household size scenario are used.
       -   Economic activity
             o The scenario is to supply further mainly work force for Linz and to avoid
                long distance commuting on a daily basis.

1
    http://www.linz.at/english/life/3199.asp

-   Mobility
           o The nature of the remote satellite town connected with a single way
              public tram is considered to serve for the transport purpose. Travel time
              should be below 30 minutes to go to the centre of Linz.

     -   Urban planning policies
           o Several alternative urban planning policies were analysed: strict anti
              urban-sprawl policies (a green belt), flood-risk zoning, mixed ownership
              of apartments: rent, rent to buy, full ownership of apartments.

[1]. Picture 2: Study of sub-centres ( Ribbon concept) : Institut für Kulturwirtschaft und Kulturforschung, JKU,
     Linz, (2008),

     -   Transport technologies and emissions
            o There was an initial plan of several ribbon town developments along the
              new transport line. This has not been fully accomplished. The new
              planning directive in Linz moved towards a concept of densification in
              the dens urban centre.
     -   Climate

o The climate data has been feed into the scenario modelling to achieve
              the desired energy demand on the building level.
    -   Building insulation regulations
          o 2 parallel scenarios are used to compare the models for energy figures.
              This has been executed not only in modelling simulation, but also in
              actual real scale buildings to provide data for a living lab.

   2. Methodology/disciplines or academic fields

Basically, the aim of the projects is to make a coupling between spatial urban
development planning and energy demand on the building level.

The measuring and testing enables to compute the actual energy demand of
buildings and neighborhoods and to compare the calculated and predicted energy
demand. In respect to building materials identical buildings are built with a variation of
construction method and materials used, such as wood, brick, concrete and
insulation.

On top of the project several additional measures such as flood risks and urban
sprawl and a leisure Park are taken care of.

Urban model
The original plan of a comprehensive master plan for 5000 inhabitants was done in
1992 by the Austrian architect Roland Rainer. The first step of realisation was done in
1994, including the formulation of the READ group (Renewable Energies in
Architecture and Design) with the partnership of Norman Foster/GB, Richard Rogers
and Thomas Herzog and the energy planer Norbert Kaiser, and sponsored also by
the European Commission DG XII.
In 1995 the total of 1300 apartments on 32 Hectare land was foreseen and in 1996, a
specialist on solar architecture was also responsible for additional area. The project
was also supported by landscape architects and sociologist, such as the Wohnbund
Salzburg.
The building phase lasted from 1999 up to 2008, the first apartments, however, were
finished in 2003. (1)
The area is situated along the river Danube and is ecological sensible. Therefore the
new settlement was considered to cover the aspect of recreational facilities and re-
cultivation of a small river and a lake. It also has a concept for grey water use.

Picture 2: Master Plan Solar City, Linz (picture: Stadt Linz)

European wide showcase of district planning including alternative use of energy in
1995.
Linz is a city with 178.000 work places and approximately 200.000 inhabitants. This
creates a pressure towards housing expanses in the centre as well as heavy day to
day commuting. That was the starting point for a new town development.
The start for realisation was also based on an agreement of the 12 social housing
companies involved to have common standards in energy figures such as hot water
solar panels and prime energy figure of below 44 kWH/ (m2a). This was also applied

to public buildings such a schools, kindergartens and similar facilities. The basic idea
was to provide at least 34% of hot water by solar panels. Reality shows a figure
almost close to 50 % and the average figure of energy/ building below 36 kWh/
(m2a). The goal was also supported by subsidies by the municipality of Linz and
resulted in a total of 3500 m2 of solar panels mounted on roofs. (2)
The problem of overheating in summer was already considered in the planning phase
and every social housing company involved had to prove by calculation to stay below
the problematic temperature. The basic orientation of buildings and its height, the
quality of the building envelope as well as the use of active and passive use of solar
energy as modelled and tested and constantly monitored in each planning phase.
The concept of low energy was introduced by combination of technical details, good
ration of volume to square metres and orientation of building blocks.
In Solar City a wide variation of typology buildings and apartments were used. It
ranges from east-west oriented rather wide building blocks including large scale
windows to south oriented houses with 6 meters high winter glass houses to passive
house standard buildings in different variations. It is meant to create a mix of various
attitudes in the spirit of solar building concepts.

                                             Picture 3 : Kindergarden, 2012 (picture: Stadt Linz)

Picture 4 : Apartment building Neue Heimat (picture: Stadt Linz)

    District Heating
Energy supply for all buildings is done by a district heating supply system. It contains
pipes of 150 mm in diameter and is linked to the overall district heating system of
Linz. The transport pipes of steel are specially insulated with polyurethanfoam
resulting in a loss of only 8% from heat generation to end –user.
The system was combined in realisation with a biomass-heating/energy plant.

    Infrastructure
The centre of the solar city is a square with facilities such as banks, grocery store,
coffee shop, a church and also a urban office dealing with social matters of
inhabitants.
Schools, and also a high education facility (Gymnasium) are in place. Close to the
centre in the north is a recreational facility.
A public tram was opened in 2005 to link the solar city by public transport to the city
centre of Linz in half an hour.
The individual transport remains with a point to point situation due to its geographic
situation and creates traffic problems during rush hours. (3)

Monitoring

A net-based assessment tool for municipalities for big urban developments in respect
to sustainability, social aspects as well as mobility and energy matters were
developed and applied to monitor the living –lab. This tool was used further on for a
sustainability check and ongoing assessment.
One example of the monitoring is the data log of various indoor –temperature in
relation to heating periods over 3 years.

                                                                                                      1
                            Picture 5 : Temperature for heating (picture: Project Eval-solar City-2010)

       3. Data sources

       1
[1].      Treberspurg, M., Smutny, R., Ertl-Balga, U., Neururer, C.Methodik
       Energiebilanz und Treibhausgasemmissionen; Forschungsprojekt Evaluation der
       Solar City- Linz-Pichling., Anhang; Arbeitsgruppe Resourcenorientiertes Bauen,
       BOKU, Wien, (2010), Seite 29

-   Linz city council data
    -   Linz, census
    -   Statistik Austria
    -   GIS-work related with ortophotos.

   4. Links with policy makers/Urban planners
These projects are developed in close collaboration with City of Linz municipality,
especially the urban planning department to achieve the overall goal of energy
reduction at the building level as well as on the urban system.

Consultation and published plans:

-Urban Master Plan.

- Urban Master Plan Revision

- District Heating

- The Lake: “Kleiner Weikerlsee”

- The Landscape park plan

- The restoration of the Aumühlen Stream

- City Map “ Doris easyMap”

   5. Results of the case studies
The Linz case has made it evident, that there is a considerable effort put into original
lay out and goals to achieve planned result.

Furthermore it had been a joint effort of the city administration, international
architects, local social housing agencies and national experts of special planning
issues to create an extension of living area in close vicinity to Linz.

The new town development was build during the early stage of CO2 neutral planning.
It is an attempt to accommodate energy efficient elements in mass housing
apartments as well as on city planning scale.
The modeling has proved realistic and the contractual goals in respect to the energy
demand are all meet.
Whereas all apartments are occupied, the problem of traffic to and from the city of
Linz was not solved satisfactorily.

It takes 30 minutes by public transport to reach the centre and considerable individual
commuting by private car very common among inhabitants of the Solar city. The
promised 2 lane rapid train connection did not materialize yet.

Main references
[2]. Treberspurg, M., Stadt Linz (Eds.), , solarCity. Linz Pichling. Nachhaltige
     Stadtentwicklung. Sustainable Urban Development 1, 1, 195; Springer Verlag,
     Wien, New York; ISBN 978-3-211-30562-1
[3]. Treberspurg, M., Smutny, R., Ertl-Balga, U., Neururer, C. (2010): Evaluation der
     solarCity     Linz-Pichling.      Detailauswertung       Passivhäuser       und
     Niedrigstenergiehäuser der EBS           und GIWOG.         Energiebilanz und
     Treibhausgasemissionen. Stadt Linz, Land Oberösterreich, EBS, GIWOG
[4]. [Lins 2009] Lins, J., Sozialwissenschaftliche Evaluierung der solarCity Pichling.
     (2009)
[5]. Wojciech Czaja, DER STANDARD, Print-Ausgabe, 4.2.2009
[6]. http://www.linz.at/leben/4677.asp (assessed on 03/24/2013)
[7]. Schmid, E., Daniela Fürst, Michaela Gusenbauer, Cornelia Hochmayr, Ingo
     Mörth Pchling ( Solar City) ; Institut für Kulturwirtschaft und Kulturforschung, JKU,
     Linz, (2008),
[8]. GNER, W., JÄHNIG, D. (2006) Messergebnisse der “Haus der Zukunft”
     Demonstrationsgebäude. Vortrag im Rahmen des Workshops „Haus der Zukunft
     in der Praxis. Themenworkshop 10: Qualitätssicherung und Messergebnisse von
     "Haus der Zukunft"-Demonstrationsgebäuden“. Graz 20.01.2006.
[9]. Treberspurg, M., Smutny, R., Ertl-Balga, U., Neururer, C.Methodik Energiebilanz
     und Treibhausgasemmissionen; Forschungsprojekt Evaluation der Solar City-
     Linz-Pichling., Anhang; Arbeitsgruppe Resourcenorientiertes Bauen, BOKU,
     Wien, (2010)

Website : http://www.linz.at/english/life/3199.asp