This review summarizes and organizes the literature on life cycle assessment (LCA), life cycle energy analysis (LCEA) and life cycle cost analysis (LCCA) studies carried out for environmental evaluation of buildings and building related industry and sector (including construction products, construction systems, buildings, and civil engineering constructions). The review shows that most LCA and LCEA are carried out in what is shown as “exemplary buildings”, that is, buildings that have been designed and constructed as low energy buildings, but there are very few studies on “traditional buildings”, that is, buildings such as those mostly found in our cities. Similarly, most studies are carried out in urban areas, while rural areas are not well represented in the literature. Finally, studies are not equally distributed around the world.

Life cycle assessment (LCA) and life cycle energy analysis (LCEA) of buildings and the building sector: A review

The energy consumption of a building is strongly dependent on the characteristics of its envelope. The thermal performance of external walls represents a key factor to increase the energy efficiency of the construction sector and to reduce greenhouse gases emissions. Thermal insulation is undoubtedly one of the best ways to reduce the energy consumption due to both winter heating and summer cooling. Insulation materials play an important role in this scenario since the selection of the correct material, its thickness and its position, allow to obtain good indoor thermal comfort conditions and adequate energy savings. Thermal properties are extremely important, but they are not the only ones to be considered when designing a building envelope: sound insulation, resistance to fire, water vapor permeability and impact on the environment and on human health need to be carefully assessed too. The purpose of the paper is to provide a review of the main commercialized insulation materials (conventional, alternative and advanced) for the building sector through a holistic and multidisciplinary approach, considering thermal properties, acoustic properties, reaction to fire and water vapor resistance; environmental issues were also taken into account by means of Life Cycle Assessment approach. A comparative analysis was performed, considering also unconventional insulation materials that are not yet present in the market. Finally a case study was conducted evaluating both thermal transmittance and dynamic thermal properties of one lightweight and three heavyweight walls, with different types of insulating materials and ways of installation (external, internal or cavity insulation).

Insulation materials for the building sector: A review and comparative analysis

A review of unconventional sustainable building insulation materials

A review on Life Cycle Assessment, Life Cycle Energy Assessment and Life Cycle Carbon Emissions Assessment on buildings

The profitability and sustainability of future biorefineries are dependent on efficient feedstock use. Therefore, it is essential to valorize lignin when using wood. We have developed an integrated biorefinery that converts 78 weight % (wt %) of birch into xylochemicals. Reductive catalytic fractionation of the wood produces a carbohydrate pulp amenable to bioethanol production and a lignin oil. After extraction of the lignin oil, the crude, unseparated mixture of phenolic monomers is catalytically funneled into 20 wt % of phenol and 9 wt % of propylene (on the basis of lignin weight) by gas-phase hydroprocessing and dealkylation; the residual phenolic oligomers (30 wt %) are used in printing ink as replacements for controversial para-nonylphenol. A techno-economic analysis predicts an economically competitive production process, and a life-cycle assessment estimates a lower carbon dioxide footprint relative to that of fossil-based production.

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A sustainable wood biorefinery for low–carbon footprint chemicals production

Acoustical sustainable materials, either natural or made from recycled materials, are quite often a valid alternative to traditional synthetic materials. The production of these materials generally has a lower environmental impact than conventional ones, though a proper analysis of their sustainability, through Life Cycle Assessment procedures, has to be carried out.Airborne sound insulation of natural materials such as flax or of recycled cellulose fibres is similar to the one of rock or glass wool. Many natural materials (bamboo, kenaf, coco fibres) show good sound absorbing performances; cork or recycled rubber layers can be very effective for impact sound insulation. These materials also show good thermal insulation properties, are often light and they are not harmful for human health. Furthermore, many of these materials are currently available on the market at competitive prices.There is however a need to complete their characterization, both from an experimental and a theoretical point of view, and...

A Review of Sustainable Materials for Acoustic Applications

The use of straw in buildings has been common since ancient times, but only at the beginning of the twentieth century house made of straw bales were built in Nebraska. After a period of abandon, due mainly to the spread of Portland concrete, this building technique has gained a new attention in the last decades, at least in a niche sector of self-builders. Indeed, the main issue that an engineer or an architect must face when he/she decides to build a straw bale house is the absence of certain data about technical performance. The aim of the present paper is to investigate a straw bale wall, both in laboratory and in situ, and to perform a Life Cycle Assessment to identify strong and weak points of this building technique. After a section reporting the state of the art of the main features of straw bale constructions, including the most important physical parameters that affect durability and indoor comfort conditions, the paper reports the results of laboratory measurements aimed at assessing the sound absorption coefficient with an impedance tube and thermal conductivity with a guarded hot plate apparatus. Then, results of in-situ measurements of thermal and sound insulation are reported. Data show that in winter (steady-state) conditions the investigated wall offers adequate thermal insulation, but the lightness of the structure can be detrimental for the summer (unsteady-state) season, leading to possible overheating in warm climates. Furthermore, the sound insulation is limited by the lightness of the structure. Finally, the Life Cycle Assessment demonstrates that the use of straw bales in walls is capable of reducing the energy and carbon embodied in the building.

Straw bale constructions: Laboratory, in field and numerical assessment of energy and environmental performance

Recycled tyre granules can be used for manufacturing acoustic insulating and absorbing materials, with applications in buildings and road barriers. Therefore, the production of these materials is a valid alternative to the disposal into landfill or incineration of used tyres. This paper presents the results of sound absorbing coefficient measurements of several samples manufactured at the Acoustics Laboratory of the University of Perugia. The sound absorbing panels were produced by mixing rubber crumbs and an adequate binder in a proper proportion and then by compacting the obtained mix. The methodology used to evaluate coefficient of absorption coefficient is indicated in ISO 10534‐2 standard, thanks to an impedance tube. The influence on the absorption performance of granules size, binder concentration, thickness and compaction ratio of the samples was investigated and an optimization process was carried out, in order to produce a sample with satisfying acoustical performances.

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Samuele Schiavoni

Papers

Insulation materials for the building sector: A review and comparative analysis

A review of unconventional sustainable building insulation materials

A Review of Sustainable Materials for Acoustic Applications

Straw bale constructions: Laboratory, in field and numerical assessment of energy and environmental performance

Sound absorbing properties of materials made of rubber crumbs