Tectonic Use of Reclaimed Timber: Design Principles for Turning Scrap into Architecture

Increasing the use of timber has been proposed as one step towards more sustainable architecture and construction. Timber's renewability and the capability to store carbon have dominated this discussion. At the same time, viewpoints related to material efficiency and recycling, equally important aspects to sustainability, have been neglected. Unfortunately, recycling wood can be challenging, and countries that already build a lot with timber tend to rely on incineration at the end of the life cycle. Reusing wood could, however, save emissions from manufacturing new timber and disposing of demolished timber and prolong the time the carbon stays sequestered. Embedded in new architectural ensembles, salvaged components could also transmit the past to the contemporary viewer and thus, result in more evocative architecture. Barriers preventing reuse in general have been documented in literature, but few solutions have been proposed. The obstacles include, among other things, inconsistent quality and quantity, difficulty of dimensional coordination and negative perception, which are all issues connected to design. This paper employs literature review and design simulation in addressing the challenges of architectural design from reclaimed timber. With the help of literature, the tectonic nature of reclaimed wood material is elaborated in more detail. The design simulation was conducted during a special timber architecture course with the help of 36 students, whose design projects form the empirical research material of the paper. Engaging in a discussion with literature and the research material, the study results in recognizing how reclaimed timber essentially differs from virgin timber and proposes ten design principles for managing the inconsistencies associated with the salvaged material. The presented discussion demonstrates that reclaimed materials should be considered as materials of their own; they should not be expected to simply comply with conventional construction methods and design practices. Since the salvaged components already exist, their architectural and structural design cannot be differentiated from each other. Therefore, tectonic expression endogenous to reclaimed materials needs to be developed in order to actuate their more widespread reuse. Whereas historical and vernacular construction methods withhold many insights for architectural design from reclaimed timber, contemporary computer-aided design offers novel tools for the execution of these ideas. The remarks of the paper are not only valid in Western contexts, but may be highly relevant for architects working in developing countries

Understanding demolition

This special issue explores when, why, and how demolition occurs with the aim to understand its environmental, socio-economic and cultural drivers and consequences in policy and practice alike. Based on previous research, demolition is known to have many adverse effects. The potential for avoiding building replacement (demolition and subsequent new build) and favouring retention is also in this special issue’s interest. The papers in the issue contribute insights from different scales, from the level of a building to that of a city. As a whole, the articles touch upon all types of impacts, i.e. environmental, economic, and socio-cultural aspects. Eight case studies from various contexts, mainly Europe but also the US and Australia, contribute novel methods, findings, and policy insights. This editorial sets the need and background for research into demolition, classifies the included papers to three categories, explains their contributions to research and practice, and outlines outstanding research gaps and agenda for further research. The papers are categorised as: (1) drivers and policies on demolition vs. retention; (2) environmental and social impact assessment on building level; and (3) practical demolition decision-making. The contributions suggest, among other findings, positive environmental impacts from building retention as opposed to demolition, and discuss how policy designs from the city to the building level can either encourage or discourage retention. Due to its implications, many of which remain understudied, demolition and its alternatives should gain importance on research, design, planning, construction and real estate agendas in the years to come.Non peer reviewe

Building 'Post-Growth': Quantifying and Characterizing Resources in the Building Stock

Building stocks will play growing roles in the extraction of secondary construction materials in future. Moreover, as there is a need to decouple buildings’ service provision from their material consumption, building stocks should, in fact, be considered not only as deposits of raw materials but also as reserves of space. Despite of their significance, these stocks tend neither to be well known nor systematically analysed. The end-of-life phase of buildings is especially poorly covered in research, although the aspects of buildings’ mortality and survival are fundamentally intertwined. The omission is highly problematic, because it precludes understanding the fundamental dynamics of the stock.The current study is situated in Finland, where the basic composition of the stock is relatively well established in the Building and Dwelling Register, contrary to many other countries. Taking advantage of statistical description, this dissertation explores the geography and characteristics of obsolete parts of the Finnish building stock, that is, demolished and problematically vacant buildings. The dynamics, or the relations, within the stock are also considered on a very basic level, with the help of a simple correlation analysis. In order to exemplify refining the results of this kind of top-down research, the study then switches to a bottom-up approach and zooms into the more specific composition of a selected age-use cohort, the 1960–80s blocks of flats. The types and dimensions of the cohort’s components, or concrete panels, are inventoried, and the results are compared to the current requirements for dimensioning living spaces. Furthermore, the spatial configurations of flats, the service provided by these physical structures, are also investigated using graph theory informed typological methodology. The findings consist of a typology of flats characteristic to the cohort. Lastly, the extents of the reserves in the entire stock of demolished buildings, the stock of problematically vacant residential buildings and the exemplary cohort (its existing, vacant and demolished parts) are quantified and proportioned to each other and new construction, inter alia.By highlighting the magnitudes of secondary deposits of materials, components and spaces, this dissertation suggests that public policy should start paying more attention to the building stock and the potentials embedded within it. Even though an unambiguous relation between vacancy and demolition was not identified, the key finding from the resource perspective is that significant amounts of obsolete buildings are geographically concentrated on cities. In order to practice sustainable policies on the building stock, planners and decision-makers should be better aware of these reserves and acknowledge their adaptation and modification capacities.<br/

Quality assurance plan for the ReCreate project

This document is the Quality Assurance Plan for the ReCreate project. The document describes the procedures to be used throughout the project to coordinate the timely delivery of high-quality deliverables, other publications, and project outcomes. This plan will act as a guide for the project leadership to ensure that quality is assured in due course before deliverables and/or other publications are submitted. In addition, the plan will help all project partners to understand their responsibilities in terms of the quality of project processes, deliverables and outcomes. The plan defines the steps of quality assurance to make it easy for the responsible partners to identify the tasks that are important for ensuring high-quality outputs and sufficient communications between relevant partners. It helps to monitor the project’s progress and to foresee difficulties that may result in delays, and defines actions to be undertaken in the occurrence of such situations.publishedVersio

Project handbook for the ReCreate project

This document is the Project Handbook for the ReCreate project. The purpose of the handbook is to support the ReCreate partners in implementing the project activities. It should be understood as an internal guidebook and a reference for the project execution. The handbook contains pieces of key information from the Grant and Consortium Agreements in an easily understandable and accessible format. It is a dynamic document that will be updated as needed throughout the lifetime of the project.publishedVersio

How changes in urban morphology translate into urban metabolisms of building stocks : A framework for spatiotemporal material flow analysis and a case study

Anthropogenic stocks are increasingly seen as potential reserves for secondary resources, which has led to a rapid development in research of urban metabolic systems. With regard to buildings and their associated material stocks and flows, one of the most critical shortcomings in the state-of-the-art is the knowledge gap for drivers, dynamics, patterns, and linkages that affect the urban metabolism. This paper presents an approach that highlights the intertwined nature of changing urban morphology and building material stocks and flows in space and time. It provides an analytical framework, based on the principles of material flow analysis, for an integrated, spatiotemporal study of urban morphology and urban metabolism of buildings, using building and plot data as the input and identifying internal processes of the urban metabolism as the output. The identified processes include greenfield development, infill construction, building replacement and shrinkage, which have tangible yet different material and environmental consequences in the form of embodied materials and CO2. The use of the framework is demonstrated with a case study in the Finnish city of Vantaa in 2000–2018. The case study shows patterns pertaining to a growing city unrestricted by geographic or historic factors, manifested as vast greenfield developments and replacement of notably young building stock. As sustainability may soon call into question both these strategies, uncovering the material consequences of a city’s past urban (re)development strategies lay the foundation for using the presented approach proactively in planning support, in pursuit of more circular economy-based and low carbon cities.publishedVersionPeer reviewe

Guidelines for a BIM-aided pre-deconstruction audit

The BIM-aided pre-deconstruction audit process is mainly a process of collecting and digitalizing data of precast concrete elements in a donor building, from which they will be deconstructed. The digital information is stored in a database that architects and structural designers can use when designing a new building with reused precast concrete elements. The ReCreate project tests the process of harvesting and reuse of precast concrete elements in four real-life projects in Europe. The goal is to gather knowledge in a wide range of topics directly connected to the reuse of precast concrete elements in structures of new buildings. By reusing these elements, they get a second life and the environmental impact of construction a new building is significantly reduced. The insights gained in the pilot projects contribute to a kind of ‘roadmap’ for collection information on donor buildings and their precast concrete elements in what we call a ‘pre-deconstruction audit’ (as opposed to the more familiar ‘pre-demolition audit’). The audit process contains all the steps necessary to start an efficient and (structurally) safe deconstruction process of a donor building. The audit process starts by collecting data from various archives and the internet, such as Google Maps and Street View. The data is entered into a visual database, a 3D BIM model. This 3D BIM model offers great advantages in managing and validating the collected data. To validate the data, determine its reliability and complete missing data, a visual inspection is performed. Additional testing supports the data and the reliability of the data. The information obtained is incorporated into the 3D BIM model in order to create a final, complete and reliable 3D BIM database containing all the necessary information of the precast concrete elements. The roadmap for collecting the data, creating a 3D BIM model (database), verifying and managing the data of the donor building and precast elements is laid down in this document as a recommendation.publishedVersio

Methods for evaluating the technical performance of reclaimed bricks

Reusing deconstructed materials and components can help to decrease the environmental burden of buildings. To safely reuse reclaimed items in new construction, methods are needed to reliably identify the essential technical properties of the deconstructed products. This paper looks at salvaged bricks and examines different indirect test methods to assess their properties. The explored test methods include visual observation, pitch of a sound, ultrasonic pulse velocity (UPV), and thin section. Reclaimed clay bricks and calcium silicate bricks were used in the research. They originated from four different buildings and from different kinds of structures. New bricks of the same kinds were also tested for reference. The assessed properties entail initial rate of water absorption, water absorption capacity, compressive strength, and freeze-thaw durability. The results show that it is possible to assess the deviation of properties and sort out exceptional bricks from a series with visual observation and pitch of a sound. The deviation of different properties can also be assessed with the help of UPV. A correlation was found between UPV and water absorption, compressive strength and freeze-thaw durability. Lower UPV values mean higher water absorption capacity and vice versa. Compressive strength of bricks is clearly lower when the UPV value is low and higher when the UPV is high. Bricks with lower UPV values ( 3.0 km/s) were found to be non-durable. Between the mentioned two values, the freeze-thaw durability varied. Thin section was only used to assess freeze-thaw durability and it was found to be unreliable as a method.publishedVersionPeer reviewe

Renovate or replace? : Consequential Replacement LCA framework for buildings

Is it more environmentally friendly to replace an existing building with a new one or to renovate the existing property? This paper addresses how to frame and evaluate this question. Although several previous studies exist, their methods lack a harmonised set of practice. A new framework is introduced that adopts the concept of consequential replacement framework (CRF) for life cycle assessment (LCA) which had previously been applied to vehicles. The application of the CRF to buildings is demonstrated with case studies on school buildings in Finland. Three alternative cases are examined: the refurbishment of a 1950s school; extending it with an annex; and demolition and replacement with a new concrete or timber building. As the European environmental impact regulation of buildings pertains to CO2 emissions, the paper also focuses on CO2. The case studies demonstrate that refurbishment in Finland is a more climate-friendly alternative to demolition and new build. The studied new buildings’ better energy efficiency is set off for decades by the carbon spike caused by the embodied CO2 in their materials. The CRF is shown to be a methodologically sound, easily approachable framework for evaluating immediate environmental consequences of decision-makers’ retention or replacement choices, suitable to different contexts. Policy relevance As the global CO2 budget is running out, the need to combat the escalation of the climate emergency is imminent. Decades-long payback times for embodied CO2 investments in new replacement buildings, as in the paper’s case studies, are not helpful in this effort. The introduced framework helps to uncover the climate change mitigation potential in building preservation, which is presently poorly understood and considered in policymaking. The new framework provides a useful decision support tool and evidence for both policymakers and planners. Current policy initiatives in Europe focus on CO2 regulation for new build and renovation. However, replacement situations are not yet regulated. In contexts where renovation clearly proves to be more climate friendly (as validated by this method), policymakers should recognise the greenhouse gas-mitigation potential in building retention and create policies to encourage renovation over new build.publishedVersionPeer reviewe

Betonielementtien uudelleenkäyttömahdollisuudet

Rakennusten purkaminen keskittyy Suomessa kasvukeskuksiin: sitä enemmän puretaan mitä enemmän rakennetaankin. Suurin osa 2000-luvulla purettujen betonirakennusten neliömetreistä on peräisin teollisuus- ja varastohalleista sekä liike- ja toimistorakennuksista. Asuinkerrostalojen purkaminen on toistaiseksi ollut vähäistä. On kuitenkin todennäköistä, että betonirakennusten purkaminen vain lisääntyy tulevaisuudessa. Betonirakentamisen volyymistä johtuen pienikin kasvu betonirakennusten purkamisessa lisää betonijätteen määrää ja prosenttiosuutta huomattavasti. EU:n jätedirektiivi vuodelta 2008, jonka mukaiseksi Suomen jätelakia muutettiin 2011, määrittelee, että kokonaisten tuotteiden valmistelu uudelleenkäyttöön on asetettava murskaavan materiaalikierrätyksen edelle. Vaikka useimpia elementtijärjestelmiä ei ole erityisesti suunniteltu elementtien ehjänä purkamista ja uudelleenkäyttöä silmälläpitäen, on erilaisissa koehankkeissa saatu siitä myös positiivisia kokemuksia. Suomen varsin nuoresta rakennuskannasta huolimatta siinä esiintyy huomattavasti korjaustarvetta. Tällaisten säälle alttiina olleiden rakenteiden uudelleenkäyttö on aina selvitettävä tapauskohtaisesti. Sellaisenaan niillä ei ole mahdollista saavuttaa nykyisin yleisesti vaadittavaa vähintään 50 vuoden käyttöikää. Sen sijaan rakennusten sisäolosuhteissa olevat rungot ovat yleensä moitteettomassa kunnossa. Rakennusten sisäilmaongelmat ovat jo pitkään olleet yksi merkittävä korjaustarvetta ja usein myös rakennusten purkamiseen johtava tekijä. Sisäilmaongelmat ovat hyvin tyypillisesti paikallisia ja ne syntyvät usean eri tekijän yhteisvaikutuksesta. Rakenneosien uudelleenkäytön kannalta huomionarvoista on, että sisäilmailmaongelmaisissakin rakennuksissa on yleensä lukuisia rakenneosia, joissa ei ole minkäänlaisia kosteus- tai mikrobivaurioita. Rakenneosien uudelleenkäyttöön vaikuttaa merkittävästi rakennuksen ja sen materiaalien ikä, rakennuksen käyttötarkoitus ja rasitus, jolle rakenteet ovat altistuneet sekä uusi käyttötarkoitus. Suurin uudelleenkäyttöpotentiaali on sellaisilla betonielementeillä, jotka voidaan irrottaa ja uudelleen asentaa helposti. Uudelleenkäyttöä suunniteltaessa pitää ottaa huomioon, että betonirakenteet, jotka on alun perin suunniteltu sisäympäristöön, eivät saa altistua uudessa käyttötarkoituksessa alkuperäistä ankarammalle rasitukselle. Runkorakenteiden merkittävin vaurioitumisriski on purkamisen ja kuljettamisen sekä muun käsittelyn aikana. Erityisesti aukollisten elementtien purkamisessa vaurioitumisriski on suuri. Betonielementtirakentamista ohjaavat normit ja ohjeet ovat muuttuneet useasti elementtirakentamisen alkuajoista lähtien. Kuormitukset ja rakenteiden kapasiteetit on tarkistettava aina tapauskohtaisesti ja tarvittaessa suunniteltava rakenteiden vahvistukset. Nykyiset lämmöneristysmääräykset edellyttävät myös lisälämmöneristystä vanhoihin ulkoseinäelementteihin. Pilari-palkkirunkoisen hallin hiilijalanjälkitarkastelut puoltavat hallin rungon uudelleenkäyttöä, sillä merkittävimmän hiilidioksidipäästöt syntyvät betonielementtien valmistamisesta. Elementtien kuljettamisen päästöt ovat vähäisiä verrattuna elementin valmistukseen, mutta ne on otettava huomioon hallin uudelleenkäytön hiilijalanjälkitarkasteluissa.<br/