BONSEI! Optimal use of existing buildings – energy efficient implementation of renovation!

The objective of the project BONSEI! is the support of an energy efficient and socially acceptable densification of privately owned residential buildings in urban space and the development of a methodological basis for resource efficient urban areas. The results are used for the conception of an innovative service in order to provide a neutral consulting regarding private densification plans.

Short Description

Starting point / motivation

Due to the extraordinarily high area consumption in Austria and the thereby induced pressure from the population especially in urban regions, there is a need for developing innovative and sustainable solutions to cover housing requirements and increase energy efficiency simultaneously.

An integrative observation of the interactions between different factors such as densification, resource efficiency and energy supply and the pursuit of a systematic, spatially transferable solution is often missing. Great potential of densification as well as large refurbishment backlog has been identified particularly in single and double household structures.

Almost the same applies to small apartment houses. To effectively activate the potentials the predominant private owners need to be contacted and convinced of actions.

Contents and goals

The main objective of BONSEI! is the development of criteria and planning principles for an energy efficient densification as an important basis for the modernisation and sustainable development of urban regions.

On the one hand the factors energy, location quality and mobility should be better integrated into the domain of densification and on the other hand interactions between densification, energy efficiency and energy supply should be better considered in the prioritisation of densification areas.

The innovative criteria which are developed within the project will serve as basis for an exemplary innovative consulting service for the mobilisation of densification- and renovation potentials for single and double family houses.


At first a methodology is designed that automatically identifies potential densification areas. Subsequently, a criteria catalogue is worked out that provides widespread recommendations on energy efficient densification concepts on both parcel and settlement level (e. g. appropriate construction methods and materials, augmented use of renewables, conservation of green spaces etc.).

By ongoing coordination with the LOI-partners in Salzburg, Vorarlberg and Vienna the spatial transferability is ensured. Based on this, a prioritisation of the identified areas is performed with regard to feasibility and urgency of actions to be taken at distinct locations. In the process the defined criteria and their interdependencies along with further local characteristics (housing demand, refurbishment backlog, legal restrictions, acceptance, incentives etc.) are integrated in a standardized mode.

Building on this, the innovative conceptual design of a service offer is supplied that illustrates urgent need and densification options to authorities and may serve as first contact point for citizens interested in objectively advice regarding refurbishment and densification issues.

Expected results

The project BONSEI! uses a cross-system approach and aims at an energy efficient and socially acceptable densification, which supports the resilience of cities and keeps quality of life at a constant level.

Important expected results

  • Transferable methodology for the automatized identification of densification potentials on parcel level
  • Criteria catalogue for energy efficient and socially acceptable densification concepts taking account of interactions between densification and energy
  • Exemplary innovative consulting service offer for the mobilisation of densification potentials

Project Partners

Project management

Research Studios Austria Forschungsgesellschaft mbH, Research
Studio iSPACE

Project or cooperation partners

  • Energieinstitut Vorarlberg
  • Architekt Paul Schweizer
  • Stadt Salzburg

Contact Address

Research Studios Austria Forschungsgesellschaft mbH,
Research Studio iSPACE
Dr. Thomas Prinz
Mag. Sabine Gadocha
Schillerstrasse 25
A-5020 Salzburg
Tel.: +43 (662) 908 585 213