Office buildings are thought to be significant sources of energy use and emissions in industrialized countries, but quantitative assessments of all of the phases of the service life of office buildings are still quite rare. In order to enable environmentally conscious design and management, this paper presents life-cycle assessments of newly constructed European and U.S. office buildings from materials production through construction, use, and maintenance to end-of-life treatment. The significant environmental aspects indicate the dominance of the use phase in the quantified environmental categories, but draw attention to the importance of embedded materials and expected maintenance investments throughout the assumed 50-year service life, especially for particulate matter emissions. The relevance of the materials, construction, maintenance, and end-of-life phases relative to the use of buildings is expected to increase considerably as functional obsolescence of office buildings becomes more rapid, and com...

This paper quantifies the significant environmental aspects of a new high-end office building over 50 years of service life. A comprehensive environmental life-cycle assessment—including data quality assessment—was conducted to provide detailed information for establishing the causal connection between the different life-cycle elements and potential environmental impacts. The results show that most of the impacts are associated with electricity use and building materials manufacturing—in particular, electricity used in lighting, HVAC systems, and outlets; heat conduction through the structures; manufacturing and maintenance of steel; manufacturing of concrete and paint; water use and wastewater generation; and office waste management. Construction and demolition were found to have relatively insignificant impacts. The identified most significant aspects are quite predominant; 7% of all counted aspects cover over 50% of the life-cycle impacts. Practical applications of the study’s results could be in the e...

Climate change, driven by greenhouse gas (GHG) emissions, is considered to be one of the most severe threats to the mankind in the future. Consequently, various institutions have set climate change mitigation targets that require substantial GHG reductions throughout all industries. The real estate and construction sector is responsible for a significant share of the global GHG emissions and therefore is expected to contribute remarkably to climate change mitigation targets. The use phase emissions had been considered to dominate the building life cycle emissions until the modern energy-efficient housing types emerged. Since then, relative shares of construction and use phase emissions have changed and the construction phase actually seems to dominate the life cycle emissions of the modern housing types. The early timing of the construction phase emissions in a building life cycle raises their harmfulness. Yet, construction of new residential areas is expected to contribute positively to climate change mitigation due to improved energy efficiency that rapidly negates the construction phase emissions. The dissertation argues that the contribution of a residential area construction to climate change is wider than what the common belief is. The studies employ hybrid LCA models that are used in assessing construction and use phase GHG emissions. The analyses include a temporal perspective, which highlights the relevance of construction phase emissions i.e. a carbon spike occurring early compared to the use phase emissions emitted in the distant future. The main argument of the dissertation is that the construction phase carbon spike is likely to turn the new residential areas' expected benefits from high energy-efficiency into undesired acceleration of climate change. This is due to significant construction phase emissions remaining in the atmosphere for a long time and increasing the atmosphere's GHG concentration for several decades. Additionally, use phase emissions occurring in the distant future contain significant uncertainties that might reduce the anticipated benefits of new energy-efficient housing. The dissertation suggests that energy renovations of the current building stock should be favoured instead of new construction projects whenever possible. Thus, the energy efficiency of the current building stock increases with less construction phase emissions. While the issue was not investigated in this dissertation, finding and utilizing low-carbon materials in new constructions and thus reducing the carbon spike would also offer a solution. Only minimizing both the construction and use phase emissions will result in true low impact residential areas.Kasvihuonekaasupäästöjen (KHK) vauhdittamaa ilmastonmuutosta pidetään yhtenä ihmiskunnan suurimmista uhista tulevaisuudessa. Useat instituutiot ovat asettaneet kaikkia toimialoja koskevia ilmastotavoitteita. Kiinteistö- ja rakennussektorilla on merkittävä vastuu ilmastotavoitteissa, sillä rakennukset aiheuttavat kolmanneksen globaaleista KHK-päästöistä. Ennen energiatehokkaita talotyyppejä käyttövaihe muodosti suurimman osan uusien rakennusten elinkaaren KHK-päästöistä. Elinkaaren eri vaiheiden osuus päästöistä on energiatehokkaiden talotyyppien myötä muuttunut; rakennusvaiheen osuus on kasvanut. Uusien asuinalueiden on kuitenkin ajateltu edistävän KHK-päästövähennyksiä, sillä korkean energiatehokkuuden hyötyjen oletetaan nopeasti ylittävän rakentamisvaiheen päästöhaitat. Väitöskirjan mukaan asuinalueen rakentaminen vaikuttaa ilmastonmuutokseen laajemmin kuin yleisesti uskotaan. Tutkimuksessa sovellettua menetelmää, hybridi-elinkaarilaskentaa, käytetään rakentamis- ja käyttövaiheiden KHK-päästölaskentaan asuinaluetasolla. Laskennassa huomioidaan myös aikanäkökulma, joka korostaa rakennusvaiheen suurien päästöjen – niin kutsutun hiilipiikin – merkittävyyttä elinkaaren alussa verrattuna myöhemmin aiheutettuihin käyttövaiheen päästöihin. Väitöskirjan pääjohtopäätöksen mukaan rakennusvaiheen hiilipiikki muuttaa uuden asuinalueen korkean energiatehokkuuden odotetut hyödyt epätoivotuksi ilmastonmuutoksen edistämiseksi. Tämä on seurausta rakennusvaiheen aikaisessa vaiheessa aiheutuneista päästöistä, jotka säilyvät ilmakehässä pitkään nostaen ilmakehän KHK-pitoisuutta useiden vuosikymmenien ajaksi. Tulevaisuuteen ajoittuviin käyttövaiheen päästöihin liittyy lisäksi merkittäviä epävarmuuksia, jotka saattavat pienentää korkeaan energiatehokkuuteen liittyviä hyötyjä. Tutkimuksen perusteella suositellaan nykyisen rakennuskannan energiakorjaamista uudisrakentamisen sijaan mahdollisuuksien niin salliessa, jolloin nykyisen rakennuskannan energiatehokkuus paranee uudisrakentamista pienemmillä korjausrakentamisen päästöillä. Myös uusien vähäpäästöisten rakennusmateriaalien kehittäminen ja käyttäminen saattaa soveltua uudisrakentamisen hiilipiikin pienentämiseen. Ainoastaan sekä rakennus- että käyttövaiheen KHK-päästöjen minimointi mahdollistaa aidosti ympäristötehokkaat asuinalueet

This study aims to review empirical research concerning the impact of green certificates on property cash flows and values, particularly from professional property investors’ perspective. The study uses discounted cash flows (DCF), a widely used property valuation method in income-generating properties, as a methodological framework. In this study, over 70 peer-reviewed studies were identified, categorized, and analyzed in the DCF framework. The reviewed studies indicated that certificates might increase the rental income and decrease the operating expenses, vacancy, and risks of a property. Together with the brand value of certificates, these enhancements should lead to an increase in property value. The number of studies has grown rapidly during the 2010s. Lately, studies have developed from asset-level to portfolio-level examinations. Although the reviewed studies found certification to be beneficial, the range of reported benefits was wide, and over half of the studies concentrated on U.S. commercial real estate markets, with a strong focus on LEED and ENERGY STAR certificates. From a property valuation perspective, applying these results to other markets and certificates might be challenging. Property values that fully reflect the environmental performance of properties would be a key to motivate mainstream investors to adopt sustainable property features.