Niklaus Kohler

Karlsruhe Institute of Technology | KIT · Institute of Building Design and Technology

The integrated description of the building geometry and the element attributes of the building information model (BIM) can reduce the effort needed to acquire data for life cycle assessment (LCA) and life cycle costing (LCC) at each design stage while supporting their potential for analyzing life cycle performances and feeding back to the design pr...

The thesis was presented at the Ecole Polytechnique Federale Lausanne (EPFL) in 1986. It was one of the first attempts to estimate the the energy necessary to build, operate and demolish a building during its life cycle. The basic methodology was LCA (life cycle assessment)and Life cycle costs. The building was described with standard building Cost...

The green and the subsequent sustainable building movements have been framed by changing societal contexts. Their main focus has been on the design of new buildings. However, these movements have neglected the life span of existing buildings and the long-term management of building stocks. The reasons why are considered: the changing interpretation...

What are the patterns and influences on the lifespan of the building stock? This paper presents (1) the reconstitution of an urban building stock composed of more than 60 000 buildings, (2) the analysis of the development of this stock over a period of 180 years (constructions and demolitions), and (3) the analysis of building mortality patterns an...

Research is presented on the estimation of the lifespan of cohorts of buildings and building stocks. This is based on the analysis of extensive longitudinal data of the 55 000 buildings in the City of Zurich from 1832 and 2010. The survival probability from different perspectives considers age, construction periods, and demolition periods for both...

Energy efficient, resource conserving and differentiated renovation of historic European building stocks

Uta Hassler and Niklaus Kohler informed that the modern engineering concept of resilience originated from material technology in the 19th century. This modern approach replaced the traditional dimensioning rules by formal rules of calculation to optimize structural safety and the reduced consumption of materials. Development of the resilience conce...

The importance of resilience is contextualized within the sustainable long-term management of the built environment. The built environment is considered as a set of different capitals (natural, physical, economic, social and cultural) with limited possibilities for substitution between the capitals. Resilience is related to other concepts used in t...

Der Beitrag stellt den Ablauf und die Resultate des Wettbewerbs „Energieeffiziente Stadt“ vor. Städten und Kommunen kommt im Hinblick auf die Umsetzung der Klimaziele der Bundesregierung eine besonders wichtige Rolle zu. Die Form des Wettbewerbs, mit expliziten Vorgaben zu den Zielen und zur Zusammensetzung der Projektkonsortien, erlaubte es, die K...

Despite significant efforts involving design and regulatory targets, no significant reduction of overall primary energy consumption and carbon emissions has been realized in the European building stock since 1975. The improved performance of new buildings has been offset by the increased size of the stock and other rebound effects. Significant gaps...

The distinction between deconstruction, demolition, and destruction shows a first attempt to classify and refine the reasons, the objectives, the form and the context of demolitions. Deconstruction is a well-defined field of engineering drawing on construction, structural design, construction management and industrial ecology. Deconstruction has tw...

The methods and technologies for generating large area and high-resolution three-dimensional (3D) building and city models offer new possibilities for realistic visualization as well as for multiple analytical interpretations. The major techniques used in reality-based city model generation are considered for their application to building stocks. 3...

Formulating a unified theory of the built environment may require that the built environment be understood as a complex social-ecological system, where multiple-related metabolisms interact at different scales. From this broad systems perspective, the dividing line between what is considered as nature and what is considered as built environment bec...

During China's rapid urbanization and modernization process, the energy and mass flows as well as the related environmental impacts of the Chinese building and infrastructure stocks deserve attention due to the high volume of construction activity, the possibly short lifespan of the new constructions, and the increasing need for energy and construc...

A new methodology is presented for estimating age distribution and survival functions of an urban building stock. This allows for a random sample of the undemolished stock together with a complete inventory count of the demolished part to create a Kaplan-Meier estimator for the survival function. This method can be applied to any building stock wit...

The built environment is composed of buildings, infrastructures and cultural landscapes (stocks). These man-made artefacts constitute a complex capital (natural, man-made, human, social and cultural) and its evolution is a crucial parameter in sustainable development. Their composition and dynamics can be modelled as flows or as capitals or combina...

Bauprojekte weisen als branchenübergreifende Unikatentwicklungen eine sehr hohe Komplexität und Dynamik auf. Dies resultiert unter anderem aus der starken Vernetzung und Abhängigkeit der unterschiedlichen Planungsaspekte, der Vielzahl an Planungsbeteiligten sowie der Einbeziehung des Auftraggebers und auch zum Teil der Nutzer in den Zielfindungspro...

The Social and Economic Value of Construction (2003), also known as the Pearce Report after its author, has been extensively discussed in the UK, but has not yet attracted the attention of the European construction industry and the wider international research and development community. The international significance of the Pearce Report is that it...

A methodology for estimating the age distribution and survival func- tions of an urban building stock is presented. A random sample of the undemolished part of the building stock together with a complete inven- tory count of the demolished part yields a Kaplan-Meier estimator for the survival function. The method was applied to real data from a Ger...

An example-based methodology is developed for estimating survival functions of large building stocks for which lifetime data is difficult to obtain, e.g. for German townships. By considering demolished as well as undemolished buildings, techniques from censored data are applied: the event considered being demolition, undemolished buildings are then...

Building design, realization, operation and refurbishment have to take into account the environmental impacts as well as the resulting costs over a long period of time. LCA methods had to be developed for buildings because of their complexity, their long life duration and through a large number of actors who are involved. This was realized by integ...

Summary The development of a life cycle structured cooperation platform is described, which is based on an integrated process and goal-oriented project model. Furthermore the structure of a life cycle oriented object structure model and its implementation in the platform are documented. The complete conceptual model is described, which represents t...

Life-cycle thinking is a holistic approach to environmental and social issues. This approach is key to the sustainable construction concept. LCA (life-cycle analysis, or life-cycle assessment) is an important tool for use in applying-life-cycle thinking to building and construction. LCA can yield vital information on material and energy flows. Beca...

Building design, realization, operation and refurbishment have to take into account the environmental impacts as well as the resulting costs over a long period of time. LCA methods had to be developed for buildings because of their complexity, their long life duration and through a large number of actors who are involved. This was realized by integ...

Although assessment models exist for evaluating buildings after they are designed, the problem is creating an appropriate tool for the design team to use during the design process to create sustainable (green) buildings. An integrated, life-cycle-oriented design tool (LEGOE) is proposed and its general criteria identified for use in practice includ...

Activities related to refurbishment of the building stock as a percentage of all building work have been constantly growing in most central European countries over the last 20 years. The main argument in this paper is the need to improve knowledge about composition of the existing building stock, the dynamics of its transformation and to relate thi...

The results of the BEQUEST project on sustainable urban development are reviewed as conceptual contributions and as a dynamic network. The objectives of BEQUEST are considered and compared to the principal achievements. The enlargement of the usual scope of sustainable urban development (SUD) and the insistence on the time and space continuity are...

The objectives and achievements of the international Green Building Challenge project are analysed. GBC is situated within the context of other international environmental methods. The differences between assessment tools, design tools, environmental management and audit tools and the large data problems entailed by these are discussed. Possible de...

Mit dem Auftrag zu einer Studie über Stöffströme und Kosten in den Bereichen Bauen und Wohnen nimmt sich die Enquete Kommission „Schutz des Menschen und der Umwelt“ eines Bereichs an, in dem große Teile der gesellschaftlich erzeugten Stoffströme anfallen. Im Jahre 1991 flossen ca. 20% der insgesamt durch die deutsche Volkswirtschaft ausgelösten Sto...

Die Resultate der beiden Ansätze weisen zum Teil erhebliche Differenzen auf. Validierung und Abgleich sind aufgrund von unterschiedlichen Systemgrenzen und bedingt durch die unvollständige Datenlage erst teilweise gelungen. Es stellen sich beträchtliche Probleme bei der Interpretation der Produktionsstatistik, die durch direkte Befragung der Herste...

Zu Untersuchungen von Stoffströmen, Emissionen, Energieverbrauch und Kosten im Sektor Hochbau wurden im Rahmen dieser Studie zwei Ansätze verfolgt. Der Top-down-Ansatz liefert eine Bilanz der Stoff-und Energieströme im Referenzjahr 1991, die sich auf der Basis makroökonomischer Daten errechnet.

Im ersten Abschnitt dieses Kapitels wird der Versuch unternommen, übergeordnete Ziele für eine nachhaltige Entwicklung im Sektor „Bauen und Wohnen“zu formulieren. Diesen werden Ergebnisse der quantitativen und qualitativen Analysen der Studie gegenübergestellt. Dabei zeigt sich, daß in vielen Fällen gegenwärtige Entwicklungstrends nicht als nachhal...

Aufgrund der starken Differenzen, die sich hinsichtlich der ermittelten Stoffströme in beiden Ansätzen ergeben haben, wurden für das berechnete Szenario zum Teil Ergebnisse aus beiden Ansätzen kombiniert, was im Folgenden bei der Darstellung der Ergebnisse noch genauer erläutert wird. Die detaillierten Betrachtungen hinsichtlich der Belastungen las...

Hier werden fünf mögliche Strategien für eine künftige Politik der Bestandsbewirtschaftung vorgestellt, deren Auswirkungen wir qualitativ diskutieren.

Ein neuer methodischer Ansatz dieser Studie besteht darin, daβ die Ergebnisse der Berechnungen über Stoffströme, Energiefluβ, Emissionen und Kosten für den Bereich Hochbau aus den Berechnungen des Bottom-up-Ansatzes (Bestandsmodell) einerseits und des Top-down-Ansatzes andererseits für das Referenzjahr ermittelt und verglichen werden können. Diese...

Im Bereich Bauen und Wohnen fallen große Teile der gesellschaftlich erzeugten Stoffströme und damit verbundene Umweltbelastungen an. Das Verhältnis zwischen Stoffeintrag und Abfall liegt je nach Systemgrenzen zwischen 3:1 und 5:1. Durch die vergleichsweise hohe durchschnittliche Lebenserwartung von Bauten und Bauteilen werden die heute verbauten St...

New forms of communication and co-operation do not have the same environmental impact pattern as current forms of work. Environmental impacts are produced by work technologies (mainly communication technologies), buildings (construction, maintenance, operation and destruction) and transport (induced by work relations and housing). The thesis that n...

In the European project REGENER, 8 partners of 5 different E.C. countries joined their efforts in order : - to define a common methodology to apply LCA in the building sector, - to develop a design toolbox and - to perform first applications of the methods, concerning e.g. the integration of renewable energies. The research activity of REGENER lead...

Zusammenfassung Die Grundlage der ökologischen Bewertung von Baustoffen, Bauteilen und Bauwerken be-steht in einer möglichst umfassenden und nachvollziehbaren Bilanzierung der Energie-und Stoffflüsse. Die Methodik der Lebenszyklusanalyse (LCA) wurde durch die Wahl geeigneter Systemgrenzen und Allokationsregeln an den Baubereich angepaßt. Für Bausto...

In the framework of the German LEGOE project, an integrated tool is developed for computer aided architectural design (CAAD), quantity surveying (catalogue of building elements), life cycle cost calculation and estimation (construction and refurbishment), direct energy consumption (heating, hot-water, electri-city) and environmental impact assessme...

On behalf of a committee of the German parliament, a study of the mass, energy and monetary flows of the German building stock has been initated. The approach was macro-economic (top-down) for the calculation of the overall flows and process oriented (bottom-up)for the detailed flows created by new construction, refurbishment, demolition and utilis...

The idea of life cycle cost was developed a quarter of a century ago. A wide dissemination of the term was given through a report for the US Secretary of Defense “Life Cycle Cost in Equipment Procuration” [LMI65]. This report was followed by a series of guide lines in the defense field and later on in other government activities. The basic definiti...

Im Rahmen des Jubiläums des Fensterherstellers WERU konnte mit Sponsorenmitteln der Firma ein Projekt realisiert werden, das in den heutigen Institutionen der Wissenschaft und Forschung, aber auch in den Sektoren Baupraxis und Zulieferer selbst, nicht durchführbar erschien: der umfassende interdisziplinäre Dialog über ein so uraltes wie diffiziles...

Die Geschichte der Baustile ist zu einem beträchtlichen Teil die Geschichte des Fensters, durch den entscheidenen Anteil, den ein Fenster zum Erscheinungsbild eines Gebäudes hat. Die Funktion des Fensters spiegelt im weitesten Sinn auch die Entwicklung der Bautechnik wider. Die Entwicklung der Anforderungen an das Innenklima und das Verstehen der k...

Advanced computer-aided architectural applications must model buildings as multi-level compositions supporting distinct points of view. Hierarchies of encapsulated, autonomous elements can be derived from ISO-STEP's General AEC Reference Model and configured for various applications. For analysis of life-cycle costs, we define a Pyramid of evaluabl...

Das Ziel der ökologischen Optimierung eines Gebäudes während seiner Lebensdauer kann zur Zeit sowohl auf Grund von fehlenden Kenntnissen als auch auf Grund nicht angepasster Planungs- und Entscheidungsstrukturen nur in sehr beschränktem Masse erreicht werden. Es gehört heute fast schon zu den Banalitäten, ein gesamtheitliches Denken bzw. Vorgehen z...

The appreciation of the performance and the costs of a building should be carried out over the entire life of the building. The usual life cycle cost approach has to be extended to the external costs. Different models of the building-energy-environment system are proposed. The building description is based on a basic physical process model which is...

Thèse (Docteur Sc.tech.)--École polytechnique fédérale de Lausanne,1986.

The application of Life Cycle Analysis to urban fragments is only relevant if situated within the larger conceptual framework of sustainable urban development. Furthermore, the traditional focus on environmental impacts has to be completed by taking into account the aspects of the long-term resource conservation of the urban fabric. The position pa...

Sustainable approaches in the choice of building components require attentive control of the building design and complex analyses of the behavior of chosen components and their ecological balance. One strategy to support sustainable approaches is the technique of integrated planing. Integrated planing comprises both, horizontal (interdisciplinary t...

In the framework of the German LEGOE project, an integrated tool is developed for computer aided architectural design (CAAD), quantity surveying (catalogue of building elements), life cycle cost calculation and estimation (construction and refurbishment), direct energy consumption (heating, hot-water, electri-city) and environmental impact assessme...

This paper introduces the Virtual Design Studio (VDS), an internet based design studio environment established by ifib. VDS transfers lessons learned through research projects in the field of Computer Supported Co-operative Work (CSCW) being carried out at ifib into design education. By training for interdisciplinary co-operation within the design...

Im Rahmen dieses Beitrages wird das Konzept eines auf die Planungsmethodik der Integralen Planung aufbauenden zielorientierten Kooperationsmodells mit seinen Partialmodellen (Aufgaben- und Zielsystem, Organisationsmodell, Prozessmodell) erläutert und dessen Umsetzung in einer internetbasierten Groupwareumgebung.

ABSTRACT: The design world of architects and engineers is changing. Costs arising during the whole life cycle of a building are being taken into account. Therefore, complex tools to support design decisions are coming up, and an increasing number of experts from a great variety of disciplines will have to cooperate in a more and more interrelated a...

The LCA methodology (SETAC) is applied to buildings. The system limits, functional units and allocation principles are explained. Inventories have been established for 150 buildings materials and linked to the ECOINVENT database. Buildings are described on the basis of specifications which are aggregated to (cost planning)-elements. There is a cata...

The first workshop on computer building representation took place in Chexbres (Switzerland), during October 1989. At that time 40 participants discussed important issues in this field of research. An informal group of participants has maintained contact since then and currently, there is a consensus that intersting work has been done in the meantim...