Comparing Embodied GHG Emissions between Environmental Product Declaration and Generic Data Models: Case of the ZEB Laboratory in Trondheim, Norway

The article aims to document and compare the embodied GHG emissions from the construction of the ZEB Laboratory in Trondheim, Norway. The process is of key importance because embodied emissions in Norway constitute the largest part of emissions from the construction sector. Moreover, the recent obligations in building regulations call for early accounting and active reduction of the carbon footprint during the design and execution processes. The emissions are estimated and compared between two models: firstly, using most data from the Environmental Product Declarations (EPDs), and then, applying only generic data from the ecoinvent database. The main difference derives from the installation of building-integrated photovoltaics (BIPVs), which cover a significant area and show a considerable difference in values. Elsewhere, the general ratio between the generic and EPD products is around 15%. The tendency affects main building materials, such as wood, metal and concrete, while layered products e.g., insulation or covering, show higher emissions in the EPDs. The assessment and improvement from the early design led to a pioneering building with low embodied emissions compared to other ZEB projects. The generic estimations are obtained quickly and can serve as the starting point to predict and reduce the carbon footprint from the conceptual stage. When a generic database of typical building materials and products is created, it can be used for other projects, shortening the calculation time. The accounting and comparison will be complete when all construction stages specified in the regulations and the building's ambition level are included in the calculations.publishedVersio

Development of climatic damage predictive tool for timber facade moisture-related damage

Development of the method for automated and adaptive assessment of mould growth in the timber frame facade is presented. A heat, air, and moisture (HAM) transport simulation using the open-source Python library HAMOPY is validated against a wellestablished software (WUFI Pro 1D). Climate input of the reference year in Norway, Oslo is used in validation. The material parameters of the 1D numerical model that influence mold growth conditions most are identified via a parametric study. The increased water vapor permeability and thermal conductivity of the outside envelope as well as the critical relative humidity threshold are selected as the model updating parameters to account for the risk of the thermal bridge, moisture leakage, and mold growth conditions variation in the model. The example of the automated parametric computation of the mold growth conditions in the facade is presented for a reference climate based on the developed and validated HAM model.publishedVersio

Zero Emission Refurbishment of the Built Environment

Nowadays, measures that aim minimum environmental impact are conceived for recent buildings. Greenhouse gas (GHG) emissions are reduced and balanced from renewable energy sources in a lifecycle perspective, while energy saving is achieved with cost-effective actions that secure comfort benefits. However, maintenance and adaptation interventions in historic buildings do not have the same objectives as in modern buildings. Additional requirements have to be followed, such as the use of materials compatible with the original and the preservation of authenticity to ensure historic, social, cultural and artistic values over time. The presented work aims to overcome the collaboration difficulties among different communities associated with heritage conservation through the definition of a framework that includes all the necessary steps from study to practice in a methodologic way. The Zero Emission Refurbishment (ZER) method considers conservative requirements and environmental impact for the selection of the most sustainable intervention measures. It recategorizes the protection status of the buildings with the decay level of the materials to find suitable low-carbon interventions that satisfy the requests of the involved stakeholders. The results, given at a district scale, enable the intervention works to be implemented through large-scale projects, thus ensuring their uniformity and reduction of time and cost of the actions. The ZER method is flexible and comprehensive, and it can be applied to diverse built environments. It can be further improved through practice and research, maintaining the principle of independence of the involved communities where the output of each community serves as the input for the other. Future work has to be motivated towards unifying the categorisation systems regardless the location, increasing the accuracy of the decay assessment for the components and pointing areas of the buildings which can serve for the production and storage of the necessary energy to reach ZER balance. The application of the method in a block of buildings in the city of Trondheim showed the reduction potential of emissions before undergoing large-scale interventions. The overall carbon footprint of the intervention measures, linked with the energy improvement of the buildings after the completion of the works, serves as an indicator for the estimation of renewable energy generated from the neighbourhood and therefore, for the shift towards Zero Emission Neighbourhoods in historic urban cities. Working with heritage buildings adds complexity to the standard interventions; however, a sustainable approach for reducing greenhouse gas emissions while at the same time ensuring the best possible preservation strategies is a challenge that needs to be faced for the present and future generations

Towards Zero-Emission Refurbishment of Historic Buildings: A Literature Review

Nowadays, restoration interventions that aim for minimum environmental impact are conceived for recent buildings. Greenhouse gas emissions are reduced using criteria met within a life-cycle analysis, while energy saving is achieved with cost-effective retrofitting actions that secure higher benefits in terms of comfort. However, conservation, restoration and retrofitting interventions in historic buildings do not have the same objectives as in modern buildings. Additional requirements have to be followed, such as the use of materials compatible with the original and the preservation of authenticity to ensure historic, artistic, cultural and social values over time. The paper presents a systematic review—at the intersection between environmental sustainability and conservation—of the state of the art of current methodological approaches applied in the sustainable refurbishment of historic buildings. It identifies research gaps in the field and highlights the paradox seen in the Scandinavian countries that are models in applying environmentally sustainable policies but still poor in integrating preservation issues

Sustainable interventions in historic buildings: A developing decisionmaking tool

Integrating multi-criteria approaches for reducing greenhouse gas emissions while, at the same time, ensuring long-term maintenance of existing buildings, is a challenge that needs to be faced by both the present and future generations. The core objective of this paper is to integrate a life cycle approach within the framework of building conservation principles to help decision makers dealing with “green” maintenance and adaptation interventions of historic buildings. The proposed approach identifies conservation principles to respect, it considers low, medium, high levels of intervention, and it analyses the impact of interventions in terms of emissions and energy consumptions that should be compensated – while the historic building is in use – with on-site renewables. The method, in the whole, allows the comparison of different intervention scenarios and the selection of the most sustainable one over a long-term management perspective of the historic building. The benefits are twofold: under the conservative perspective, for helping in choosing the right time of interventions, in reducing the decay rate, in using materials that endure longer and are compatible with existing fabrics; under the environmental perspective, for helping in reducing the carbon footprint, in supporting conservation needs through a minimal intervention approach, and in encouraging materials reuse and renewable energy systems

Indoor Multi-Risk Scenarios of Climate Change Effects on Building Materials in Scandinavian Countries

Within the built environment, historic buildings are among the most vulnerable structures to the climate change impact. In the Scandinavian countries, the risk from climatic changes is more pronounced and the right adaptation interventions should be chosen properly. This article, through a multidisciplinary approach, links the majority of climate-induced decay variables for different building materials with the buildings’ capacity to change due to their protection status. The method tends to be general as it assesses the decay level for different building materials, sizes, and locations. The application of the method in 38 locations in the Scandinavian countries shows that the risk from climatic changes is imminent. In the far future (2071–2100), chemical and biological decays will slightly increase, especially in the southern part of the peninsula, while the mechanical decay of the building materials kept indoors will generally decrease. Furthermore, the merge of the decay results with the protection level of the building will serve as a good indicator to plan the right level and time of intervention for adapting to the future climatic changes

Refurbishment of historic buildings at a district scale: Enhancement of cultural value and emission reduction potential

The historic buildings have a significant value in providing a sense of identity to the cities and the community. On the other hand, due to their age, they show the highest ratio of living discomfort and energy consumption. Therefore, their refurbishment is a very important process because, if done right, it will not only reduce their energy demand and increase the living comfort and sense of cultural identity, but will also strengthen the social and cultural benefits through leisure and tourism. In the city of Trondheim, as in many other European cities, the historic buildings have been erected in different architectural periods, which manifest diverse historic and technical features. A categorisation of the wall sections of historic buildings has been done for each city’s development period regarding their construction material and technique, building functionality and protection status. The scope of the article is to estimate the potential for reduction of greenhouse gas emissions at a street/neighbourhood/city level prior to applying large-scale intervention measures. This can be achieved by proposing refurbishment alternatives for wall and window sections that preserve the historic value and at the same time, approach or even meet the actual technical standards. Afterwards, the carbon footprint of the refurbishment action itself and the environmental benefits after the refurbishment (operational phase) is estimated for each category of wall sections. The environmental results, multiplied with the total surface of sections carrying the same attributes, give the overall potential of reduction for the entire group of buildings. Based on this, the on-site renewable energy that would lead to achieving zero-emission targets can be calculated. The framework is also important because it does not treat each building separately, but it suggests refurbishment scenarios for specific categories of buildings built in different historical periods

Service life prediction of building components in the times of climate change

Buildings components and assemblies are prone to decay over time due to the inherent characteristics of the materials, environmental conditions and operational use of them. For this reason, it is very important to know the right time and type of maintenance and adaptation interventions that need to be applied to the specific compounds. The answer to the above issue can be given through the service life prediction (SLP) of the components by using standardized calculation methods. In historic buildings, the process of SLP takes significant importance because these buildings hold non-renewable cultural heritage value and therefore, the interventions should be performed in a way that preserves the original material and value while enhancing the service life. Nowadays, for such buildings that are predicted to live for centuries, the SLP needs to be corrected by considering the effects of climate change in the construction materials. The paper presents an overview of the application of the well-known factor method in the estimation of the serviceability of the building components, with a special focus on historic buildings impacted by climate change. The technical compatibility, economic viability, use of the building and the indoor/outdoor environments are considered during the assessment of the service life which is strictly linked with the level of decay. It gives a short explanation of the factors that constitute the method by including the effects of climate change and an example of application to a specific case study in Norway

Balanced Evaluation of Structural and Environmental Performances in Building Design

The design of new buildings, and even more the rehabilitation of existing ones, needs to satisfy modern criteria in terms of energy efficiency and environmental performance, within the context of adequate safety requirements. Tackling all these needs at the same time is cumbersome, as demonstrated by several experiences during recent earthquakes, where the improvement of energy performance vanished by seismic-induced damages. The costs of energy retrofitting must be added to the normal losses caused by the earthquake. Even though the minimum safety requirements are met (no collapse), the damage due to earthquake might be enough to waste the investment made to improve energy efficiency. Since these measures are often facilitated by corresponding incentives, the use of public funding is not cost effective. The application of the existing impact assessment methods is typically performed at the end of the architectural and structural design process. Thus, no real optimisation can be achieved, because a good structural solution could correspond to a poor environmental performance and vice versa. The proposed Sustainable Structural Design method (SSD) considers both environmental and structural parameters in the life cycle perspective. The integration of environmental data in the structural performance is the focus of the method. Structural performances are considered in a probabilistic approach, through the introduction of a simplified Performance Based Assessment method. Finally, the SSD method is implemented with a case-study of an office-occupancy building, both for precast and cast-in-situ structural systems, with the aim to find the best solution in terms of sustainability and structural performance for the case at hand.JRC.E.4-Safety and Security of Building

Balanced Evaluation of Structural and Environmental Performances in Building Design

The design of new buildings, and even more the rehabilitation of existing ones, needs to satisfy modern criteria in terms of energy efficiency and environmental performance, within the context of adequate safety requirements. Tackling all these needs at the same time is cumbersome, as demonstrated by several experiences during recent earthquakes, where the improvement of energy performance vanished by seismic-induced damages. The costs of energy retrofitting must be added to the normal losses caused by the earthquake. Even though the minimum safety requirements are met (no collapse), the damage due to earthquake might be enough to waste the investment made to improve energy efficiency. Since these measures are often facilitated by corresponding incentives, the use of public funding is not cost effective. The application of the existing impact assessment methods is typically performed at the end of the architectural and structural design process. Thus, no real optimisation can be achieved, because a good structural solution could correspond to a poor environmental performance and vice versa. The proposed Sustainable Structural Design method (SSD) considers both environmental and structural parameters in the life cycle perspective. The integration of environmental data in the structural performance is the focus of the method. Structural performances are considered in a probabilistic approach, through the introduction of a simplified Performance Based Assessment method. Finally, the SSD method is implemented with a case-study of an office-occupancy building, both for precast and cast-in-situ structural systems, with the aim to find the best solution in terms of sustainability and structural performance for the case at hand