idw – Informationsdienst Wissenschaft
Nachrichten, Termine, Experten
Nachrichten, Termine, Experten
A consortium involving TU Graz has developed technical methods for the sustainable extension of existing Wilhelminian (Gründerzeit) buildings using modular timber constructions.
It is difficult to reconcile avoiding further soil sealing with the increasing demand for inner-city living space. In the “HOT – Holz-on-Top” (Wood on Top) project, a consortium comprising holz.bau forschungs GmbH, the Institute of Timber Engineering and Wood Technology, the Institute of Architecture Technology, the Institute for Building Physics, Services and Construction (all at Graz University of Technology/TU Graz), and rosenfelder & höfler consulting engineers, methods have been developed to precisely achieve this using sustainable building materials. These methods enable the densification of Wilhelminian (Gründerzeit) buildings using modularised timber construction without compromising their original character.
New living space for tens of thousands
The idea for the project goes back to Ida Pirstinger’s doctoral thesis from 2013 entitled “Gründerzeitstadt 2.1” (Gründerzeit city 2.1), conducted at the Institute of Design and Building Typology at TU Graz. The work focused on the potential for redensification in Gründerzeit neighbourhoods for inner city expansion. The calculations made revealed that this could provide an additional living space for around 35,000 people in Graz alone, provided that only the best and most suitable blocks of flats are redensified. Comparable analyses conducted for Vienna identified a potential to accommodate approximately 54,000 additional residents through increased housing capacity.
“This analysis clearly showed that a lot of living space can still be created in the city centre for further population growth without having to seal off new areas,” says Andreas Ringhofer from the Institute of Timber Engineering and Wood Technology at TU Graz, who is also Chief Executive Officer of holz.bau forschungs GmbH. “In the Holz-On-Top project, we have now developed the technical measures to be able to utilise this potential in practice.”
Surveys of 45 roof trusses
In order to ensure that the measures fulfil the relevant requirements, the researchers began by surveying the current stock. As part of a preliminary study, they inspected 45 roof structures of Gründerzeit buildings in Graz and assessed their structural integrity. One of the findings was that more than 80 percent of the analysed roof structures will require repair within the next five years. For roof structures worthy of preservation, the researchers are planning repair measures to preserve buildings displaying exceptional craftsmanship For roof structures not considered worthy of preservation, a redensification concept was developed that allows for the addition of up to two storeys while retaining the existing roof shape. This concept also meets the requirements of designated conservation zones.
Building on this, the team developed a modular building technology concept and, in collaboration with rosenfelder & höfler consulting engineers, a catalogue of key building physics details for extending buildings by one or two storeys. This concept is based on a grid of reinforced concrete girders covered with cross-laminated timber. The new roof structure comprises a new type of folded girder, which is a triangular cross-laminated timber girder.
In addition to minimal intervention in the existing building, the solution aimed to be broadly applicable. Key factors included a high degree of prefabrication and a correspondingly short construction period. In addition, the floor plan can be designed flexibly to respond to varying spatial conditions and housing requirements (one or more residential units). The team also ensured that the constructions were both resilient and easy to inspect and repair.
Applicable to 85 percent of roof trusses
The integration of the building technology is flexibly designed; the variants range from minimal to extensive features. The common factor is that the lengths of the water-carrying pipes are kept as short as possible and the pipe routing is centralised. This means that the prefabricated, modular building components can be better integrated and remain accessible. To find a sustainable heating solution, the redensification concept includes air-to-water heat pumps.
“We have already analysed the final design of the 'Holz-on-Top' concept with regard to its applicability based on the roof trusses we have examined. It can be applied to 85 percent of them,” says project manager Dominik Matzler. “With our detailed planning guidelines and freely available planning software (CLTdesigner) for calculating timber-concrete composite elements, we have all the tools we need to realise the 'Holz-on-Top' concept – not only for Gründerzeit buildings, but also for other existing buildings. Now it is up to the decision-makers and property owners to adopt this concept.”
This FFG research project (No. FO999896398) is funded by the Austrian Forest Fund, an initiative of the Federal Ministry of Agriculture and Forestry, Climate and Environmental Protection, Regions and Water Management, and carried out as part of the THINK.WOOD program of the Austrian Wood Initiative. The other project partners were: Handler Bau GmbH, Hasslacher Holding GmbH, KLH Massivholz GmbH, Mayr-Melnhof Holz Holding AG, Stora Enso Wood Products GmbH, Lieb Bau Weiz GmbH & Co KG.
Dominik MATZLER
Dipl.-Ing. BSc
holz.bau Forschungs GmbH
Tel.: +43 316 873 4623
dominik.matzler@tugraz.at
Andreas RINGHOFER
Dipl.-Ing. Dr.techn.
TU Graz | Institute of Timber Engineering and Wood Technology
holz.bau Forschungs GmbH
Tel.: +43 316 873 4614
andreas.ringhofer@tugraz.at
https://www.cltdesigner.at/en/ To the freely available CLTdesigner
Modules and a triangular cross-laminated timber girder for adding storeys to the building.
Dominik Matzler
holz.bau forschungs GmbH
PV panels could also be installed.
Dominik Matzler
holz.bau forschungs GmbH
Criteria of this press release:
Business and commerce, Journalists, all interested persons
Construction / architecture, Environment / ecology
transregional, national
Research projects, Transfer of Science or Research
English
Modules and a triangular cross-laminated timber girder for adding storeys to the building.
Dominik Matzler
holz.bau forschungs GmbH
PV panels could also be installed.
Dominik Matzler
holz.bau forschungs GmbH
You can combine search terms with and, or and/or not, e.g. Philo not logy.
You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).
Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.
You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).
If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).
