Analyse comparative de l’approche bioclimatique et de la méthode LEED en architecture

Motivé par l’évolution de la production architecturale durable dans les pays d’Amérique latine, et plus particulièrement en Colombie, mon projet de recherche porte sur l’adaptation de l’architecture à ce nouveau contexte. L’approche architecturale traditionnelle à la prise en compte de l’énergie et du climat est l’architecture bioclimatique : reproduite à partir de connaissances et techniques ancestrales remontant à la conception de l’abri, cette dernière étudie les phénomènes physiques associés au confort thermique afin de les reproduire dans une nouvelle architecture. De nouvelles méthodes d’évaluation environnementale se sont développées dans les dernières décennies pour améliorer l’intégration environnementale des bâtiments. Ces méthodes privilégient la normalisation des solutions et utilisent des systèmes de certification pour reconnaître la performance environnementale et énergétique des bâtiments. Le résultat visé est la conformité aux standards internationaux de durabilité. Ce mémoire porte sur l’analyse comparative de l’architecture bioclimatique et de la certification environnementale à partir de la structure des sujets abordés par LEED, une des méthodes les plus connues d’une telle certification. Cette comparaison permet de constater que les deux approches sont motivées par les mêmes préoccupations environnementales mais que leurs méthodes d’intégration de ces préoccupations diffèrent, en particulier quant à la prise en compte des facteurs locaux et globaux.

Ernesto N. Rogers y la preesistenza ambientale en las Escuelas Nacionales de Arte de La Habana

La influencia de Ernesto Nathan Rogers fue decisiva en la formación de gran parte de los arquitectos de la posguerra europea. A través de los numerosos libros' y escritos que publicó, entre los que destacan sus editoriales de la revista Casabella, que dirigió entre 1953 y 1965, desarrolló un corpus teórico en el que intentó establecer un puente entre la modernidad y la tradición. El pensamiento de Rogers quedó esbozado en el primer editorial que escribió para la revista Casabella a la que añadió el famoso término Continuitá. Las enseñanzas de Rogers calaron profundamente en tres jóvenes arquitectos que se formaron bajo el influjo de sus teorías: dos de ellos italianos, Vittorio Garatti y Roberto Gottardi, y otro cubano, Ricardo Porro. Durante sus años de formación, los tres entraron en contacto con la figura de Rogers. Garatti lo tuvo como profesor en el Politécnico de Milán. Gottardi fue el que más contacto tuvo, trabajando en su oficina entre 1956 y 1957, antes de su partida hacia Venezuela. Y Porro, de forma más efímera, a través de un curso de verano del CIAM en el año 1951 que se desarrolló en Venecia, en el que Rogers participó. Las Escuelas Nacionales de Arte de La Habana fueron sin lugar a dudas un laboratorio experimental donde estos tres jóvenes arquitectos idealistas pusieron en práctica una nueva forma de entender la arquitectura, que en ese momento se estaba gestando, a partir de una mirada crítica hacia el Movimiento Moderno. Pero este proyecto no se hubiese llevado a cabo con éxito sin las enseñanzas recogidas de uno de sus maestros, Ernesto Nathan Rogers, y que se podrían resumir en siguientes aspectos primordiales: el valor que para Rogers tenia la tradición en la arquitectura, tradición que los tres arquitectos recogerán claramente en La Habana; en la valoración de las preexistencias ambientales; en la continuidad que debía tener la nueva arquitectura con los ideales de los maestros del Movimiento Moderno; y, por último, la responsabilidad del intelectual y del artista en el contexto de la sociedad.

ORDENAMIENTO Y BALANCE ENERGETICO

No presenta resumen este articulo.

The comparison of international and local sustainable assessment tools of landscape design for housing estate developments : case of Bangkok Metropolitan Region, Thailand

Various countries have been introducing sustainable assessment tools for real estate design to produce integrated sustainability components not just for the building, but also the landscape component of the development. This paper aims to present the comparison between international and local assessment tools of landscape design for housing estate developments in Bangkok Metropolitan Region (BMR), Thailand. The methodologies used are to review, then compare and identify discrepancy indicators among the tools. This paper will examine four international tools; LEED for Neighbourhood Development (LEED – ND) of United State of America (USA), EnviroDevelopment standards of Australia, Residential Landscape Sustainability of United Kingdom (UK) and Green Mark for Infrastructure of Singapore; and three BMR’s existing tools; Land Subdivision Act B.E. 2543, Environmental Impact Assessment Monitoring Awards (EIA-MA) and Thai’s Rating for Energy and Environmental Sustainability of New construction and major renovation (TREES-NC). The findings show that there are twenty two elements of three categories which are neighbourhood design, community management, and environmental condition. Moreover, only one element in neighbourhood designs different between the international and local tools. The sustainable assessment tools have existed in BMR but they are not complete in only one assessment tool. Thus, the development of new comprehensive assessment tool will be necessary in BMR; however, it should meet the specific environment and climate condition for housing estate development at BMR.

The future of sustainable building assessment tools : a case study in Australia

Sustainability issues in built environment have attracted an increasingly level of attention from both the general public and the industry. As a result, a number of green building assessment tools have been developed such as the Leadership in Energy and Environmental Design (LEED) and the BRE Environmental Assessment Method (BREEAM), etc. This paper critically reviewed the assessment tools developed in Australian context, i.e. the Green Star rating tools developed by the Green Building Council of Australia. A particular focus is given to the recent developments of these assessment tools. The results showed that the office buildings take the biggest share of Green Star rated buildings. Similarly, sustainable building assessments seem to be more performance oriented which focuses on the operation stage of buildings. In addition, stakeholder engagement during the decision making process is encouraged. These findings provide useful references to the development of next generation of sustainable building assessment tools.

Defining sustainability requirements for design-build (DB) contractor selection in public sector projects

The design-build (DB) delivery system is an effective means of delivering a green construction project and selecting an appropriate contractor is critical to project success. Moreover, the delivery of green buildings requires specific design, construction and operation and maintenance considerations not generally encountered in the procurement of conventional buildings. Specifying clear sustainability requirements to potential contractors is particularly important in achieving sustainable project goals. However, many client/owners either do not explicitly specify sustainability requirements or do so in a prescriptive manner during the project procurement process. This paper investigates the current state-of-the-art procurement process used in specifying the sustainability requirements of the public sector in the USA construction market by means of a robust content analysis of 40 design-build requests for proposals (RFPs). The results of the content analysis indicate that the sustainability requirement is one of the most important dimensions in the best-value evaluation of DB contractors. Client/owners predominantly specify the LEED certification levels (e.g. LEED Certified, Silver, Gold, and Platinum) for a particular facility, and include the sustainability requirements as selection criteria (with specific importance weightings) for contractor evolution. Additionally, larger size projects tend to allocate higher importance weightings to sustainability requirements.This study provides public DB client/owners with a number of practical implications for selecting appropriate design-builders for sustainable DB projects.

Design-build contractor selection for public sustainable buildings

Design-build (DB) is regarded as an effective means of delivering high performance green buildings, and the selection of DB contractors is of critical importance. The objective of this study is to evaluate the selection of design-builders for public buildings seeking Leadership in Energy and Environmental Design (LEED) certification and compare the selection practices involved with those of non-LEED-seeking DB projects through a robust content analysis of 74 DB request for proposals (RFPs) for public DB projects. The results of the content analysis reveal that the level of LEED certification is the dominant means of conveying the sustainability requirements in RFPs for contractor selection, with the majority of RFPs (60%) including sustainability requirements as part of the contractor evaluation package. With the exception of contractors' past performance, there is no statistically significant difference in the importance weightings of selection criteria between LEED-seeking and non-LEED-seeking buildings, and DB owners tend to place more emphasis on innovative technical solutions rather than the past performance of DB contractors. Additionally, the research findings also indicate that owners of LEED-seeking building projects tend to provide less design decisions in RFPs in order to solicit innovative design alternatives from potential DB contractors. This study provides DB owners with a number of practical implications for selecting appropriate design-builders for green DB projects.

How public owners communicate the sustainability requirements of green design-build projects

The design-build (DB) system is regarded as an effective means of delivering sustainable buildings. Specifying clear sustainability requirements to potential contractors is of great importance to project success. This research investigates the current state-of-the-practice for the definition of sustainability requirements within the public sectors of the U.S. construction market using a robust content analysis of 49 DB requests for proposals (RFPs). The results reveal that owners predominantly communicate their desired level of sustainability through the LEED certification system. The sustainability requirement has become an important dimension for the best-value evaluation of DB contractors with specific importance weightings of up to 25%. Additionally, owners of larger projects and who provide less design information in their RFPs generally allocate significantly higher importance weightings to sustainability requirements. The primary knowledge contribution of this study to the construction industry is the reveal of current trend in DB procurement for green projects. The findings also provide owners, architects, engineers, and constructors with an effective means of communicating sustainability objectives in solicitation documents.

Energy use assessment of educational buildings: Toward a campus-wide sustainable energy policy

The purpose of this article is to assess the viability of blanket sustainability policies, such as Building Rating Systems in achieving energy efficiency in university campus buildings. We analyzed the energy consumption trends of 10 LEED-certified buildings and 14 non-LEED certified buildings at a major university in the US. Energy Use Intensity (EUI) of the LEED buildings was significantly higher (EUILEED= 331.20 kBtu/sf/yr) than non-LEED buildings (EUInon-LEED=222.70 kBtu/sf/yr); however, the median EUI values were comparable (EUILEED= 172.64 and EUInon-LEED= 178.16). Because the distributions of EUI values were non-symmetrical in this dataset, both measures can be used for energy comparisons—this was also evident when EUI computations exclude outliers, EUILEED=171.82 and EUInon-LEED=195.41. Additional analyses were conducted to further explore the impact of LEED certification on university campus buildings energy performance. No statistically significant differences were observed between certified and non-certified buildings through a range of robust comparison criteria. These findings were then leveraged to devise strategies to achieve sustainable energy policies for university campus buildings and to identify potential issues with portfolio level building energy performance comparisons.

A comparison of international and Australian rating tools for sustainability elements of residential property

The Australian housing sector contributes about a fifth of national greenhouse gas (GHG) emissions. GHG emissions contribute to climate change which leads to an increase in the occurrence or intensity of natural disasters and damage of houses. To ensure housing performance in the face of climate change, various rating tools for residential property have been introduced in different countries. The aim of this paper is to present a preliminary comparison between international and Australian rating tools in terms of purpose, use and sustainability elements for residential property. The methodologies used are to review, classify, compare and identify similarities and differences between rating tools. Two international tools, Building Research Establishment Environmental Assessment Methodology (BREEAM) (UK) and Leadership in Energy and Environmental Design for Homes (LEED-Homes) (USA), will be compared to two Australian tools, Green Star – Multi Unit Residential v1 and EnviroDevelopment. All four rating tools include management, energy, water and material aspects. The findings reveal thirteen elements that fall under three categories: spatial planning, occupants’ health and comfort, and environmental conditions. The variations in different tools may result from differences in local prevailing climate. Not all sustainability elements covered by international rating tools are included in the Australian rating tools. The voluntary nature of the tools implies they are not broadly applied in their respective market and that there is a policy implementation gap. A comprehensive rating tool could be developed in Australia to promote and lessen the confusion about sustainable housing, which in turn assist in improving the supply and demand of sustainable housing.

Time and cost performance of design–build projects

The design-build (DB) delivery method has been widely used in the United States due to its reputed superior cost and time performance. However, rigorous studies have produced inconclusive support and only in terms of overall results, with few attempts being made to relate project characteristics with performance levels. This paper provides a larger and more finely grained analysis of a set of 418 DB projects from the online project database of the Design-Build Institute of America (DBIA), in terms of the time-overrun rate (TOR), early start rate (ESR), early completion rate (ECR) and cost overrun rate (COR) associated with project type (e.g., commercial/institutional buildings and civil infrastructure projects), owners (e.g., Department of Defense and private corporations), procurement methods (e.g., ‘best value with discussion’ and qualifications-based selection), contract methods (e.g., lump sum and GMP) and LEED levels (e.g., gold and silver). The results show ‘best value with discussion’ to be the dominant procurement method and lump sum the most frequently used contract method. The DB method provides relatively good time performance, with more than 75% of DB projects completed on time or before schedule. However, with more than 50% of DB projects cost overrunning, the DB advantage of cost saving remains uncertain. ANOVA tests indicate that DB projects within different procurement methods have significantly different time performance and that different owner types and contract methods significantly affect cost performance. In addition to contributing to empirical knowledge concerning the cost and time performance of DB projects with new solid evidence from a large sample size, the findings and practical implications of this study are beneficial to owners in understanding the likely schedule and budget implications involved for their particular project characteristics.

Peilissä oma kuva : Tutkielma Einojuhani Rautavaaran omaelämäkerrasta

Tutkielma käsittelee Einojuhani Rautavaaran omaelämäkertaa (Omakuva, 1989). Työssä on lähdetty liikkeelle Omakuvan lehdistövastaanotosta, jossa kyseenalaistettiin teoksen "totuudellisuus". Useat arvostelijat esimerkiksi pohtivat Omakuvan asemaa fakta-fiktio-akselilla ja viittasivat teoksen romaanimaisuuteen.Tutkielmassa on etsitty selityksiä sille, miksi lukija joutuu kyseenalaistamaan teoksen 'totuudellisuuden' sekä lisäksi sitä, millaisia merkityksiä teoksessa annetaan omalle menneisyydelle. Rautavaaran Omakuva on suhteutettu työssä autobiografian genren kanssa ja analyyttisen tarkastelun lähtökohtana on käytetty Philippe Lejeunen narratologista autobiografiateoriaa. Rautavaaran omaelämäkerta sisältää hyvin heterogeenista ainesta, mutta teos on mielestäni autobiografia eikä se kuulu esimerkisi muistelmien tai omakuvan lajiin. Omakuva kuitenkin horjuttaa lukijan kanssa tehtyä autobiografista ja referentiaalista sopimusta, joka on Lejeunen teorian lähtökohta, eikä siten sopeudu autobiografian lukemisen konventionaalisiin pelisääntöihin. Omakuvan teksti on lisäksi narsistisesti itsetietoista omasta kerronnallisesta identiteetistään, ja teksti pakottaa lukijan havaitsemaan, että tarina on vain tekijän retrospektiivisesti kirjoittama tulkinta elämästään. Rautavaara näkee peilissä paitsi oman kuvansa myös kuvan romanttisesta taiteilijasta. Romanttisen taiteilijamyytin representoituminen tekstissä on keskeinen teoksen 'totuudellisuutta' horjuttava piirre, koska se pakottaa lukijan kysymään, onko peilissä nähty omakuva aito ja todellinen vai onko se kenties tuotettu tietoisesti ja manipuloiden. Omakuvan Rautavaara on romanttinen taiteilija, joka tahtoisi vetäytyä norsunluutornin/erakkoluolan yksinäisyyteen ja pystyttää muurin taiteen ja elämän arvojen välille. Säveltäjän minä on myös konfliktissa häntä ympäröivän yhteiskunnan kanssa ja esimerkiksi kriitikot, muusikot ja kapellimestarit uhkaavat hänen olemassaoloaan. Omakuvan päähenkilö muistuttaakin hyvin paljon Maurice Beeben (1964) tutkimien taiteilijaromaanien päähenkilöitä ja erityisesti James Joycen romaanin Taiteilijan omakuva nuoruuden vuosilta päähenkilöä Stephen Dedalusta. Omakuva lähestyy taiteilijaromaaneille tyypillisiä tapoja kuvata taiteilijaa. Teoksessa käsitellään elämää sekä autobiografisessa että taiteilijaromaanin genren tilassa. Omakuva onkin rajateksti, joka horjuttaa autobiografian lajikonventioita. Lisäksi teoksen minä piiloutuu arkkityyppisten kuvien ja myyttien taakse kieltäen jähmettymisen yhdeksi kuvaksi. Lukijalle tarjoutuukin tekstissä monta mahdollista kuvaa Rautavaarasta ja Omakuvasta tulee erilaisten subjektien näyttämö. Avainsanat: säveltäjäautobiografia, romanttinen taiteilijamyytti, kulttuurinen musiikintutkimus

Surface Structures of Silicon and Germanium

Si and Ge were cleaved on the (111) plane under ultra high vacuum and exposed to O and subsequent heat treatment. LEED and spot photometric measurements were taken. Cleaved surfaces for both Si and Ge gave the expected (2 x 1) structure. Results for O exposure were qualitatively for Si and Ge. The 1/2 orders disappeared after exposure to approx = 10 exp - exp 7. Integral orders started to weaken at 10 exp -6 to 10 exp - exp 2 torr min., disappearing at 10 exp -1 torr min. Heat treatment of Si at 900 deg C for several seconds restored the integral orders and further heating gave a new pattern with 1/3 orders. Exposure to 2 x 10 exp -6 torr min O without further heating weakened the fractional orders and at 10 exp -5 torr min they disappeared. Integral orders remained after further heating in O. For Ge integral orders were not restored after 0 exposure until heat treatment had continued at 550 deg C for several min. The (1 x 1) structure disappeared after heating at 590 deg C in 7 x 10 exp -1 torr O and further heating at 590 deg C without O restored the integral order Variations of intensity with voltage were measured for the (00) and (20) spots. The results supported a model proposed by Haneman (Phys. Rev., 1968, 170, 705) involving two kinds of atom sites on the cleaved surface. 20 ref.--E.J.S.

Nature of nitrogen adsorbed on transition metal surfaces as revealed by electron spectroscopy and cognate techniques

The nature of the chemisorbed states of nitrogen on various transition metal surfaces is discussed comprehensively on the basis of the results of electron spectroscopic investigations augmented by those from other techniques such as LEED and thermal desorption. A brief discussion of the photoemission spectra of free N2, a comparison of adsorbed N2 and CO as well as of physisorption of N2 on metal surfaces is also presented. We discuss the chemisorption of N2 on the surfaces of certain metals (e.g. Ni, Fe, Ru and W) in some detail, paying considerable attention to the effect of electropositive and electronegative surface modifiers. Features of the various chemisorbed states (one or more weakly chemisorbed gamma-states, strongly chemisorbed alpha-states with bond orders between 1 and 2. and dissociative chemisorbed beta-states) on different surfaces are described and relations between them indicated. While the gamma-state could be a precursor of the alpha-state, the alpha-state could be the precursor of the beta-state and this kind of information is of direct relevance to ammonia synthesis. The nature of adsorption of N2 on the surfaces of some metals (e.g. Cr, Co) deserves further study and such investigations might as well suggest alternative catalysts for ammonia synthesis.

Una mirada al sector energético

"Producción de hidrocarburos con tendencia negativa. A un año de la estatización de YPF, la producción de hidrocarburos sigue mostrando tasas de variación negativas. Los problemas de políticas están afectando la rentabilidad del sector y con ello la inversión en exploración de nuevas áreas. Ante esta situación, el rubro de Combustibles y Energía arrojó un déficit de US$4.300 millones en Marzo 2013 (acumulado 12 meses), lo que equivale al 40% de superávit comercial del mismo período. Dicho en otras palabras, si no fuera por el déficit que está generando el sector energético, el superávit comercial sería superior en un 40%..."