Multi-layer facades: What happens behind?

Buildings account for nearly 40% of the global process and industrial greenhouse gas emissions, and within the building sector. And within the building sector, nearly 72% of the CO2 emissions are due operational carbon demand in the building sector. To meet the goals set out in the Paris Accord, we need to halve carbon emissions by the end of this decade: an aggressive and ambitious timeline. It has become an immediate and urgent need to design and construct buildings that are minimally intrusive in their impact on the environment and operate efficiently. Improvement of the building's energy performance must begin at the early design stage as the potential for sustainable intervention in the project's early phases is higher. The opportunity to improve building performance as the design progresses, is constantly reducing, while the cost of optimization is constantly increasing. One of the major design variables impacting the performance at the early phase is the building morphology/form and its associated variables. Sensible optioneering of the building form and its variables at the early stages of design - especially the conceptual design stage - can help improve the performance of the design early on in the design process at minimum cost. However, for effective early-phase design optimisation, there is a need to develop tools/methods that allow instantaneous evaluation of a large design sample space without much “lag” between the design and performance evaluation workflows. Also, in regular early phase sustainable design workflows, multiple stakeholders - like the designer, the performance analyst, etc. - are involved, which leads to a cognitive divide in the design process. For instance, while the architect designs the initial conceptual massing with a functional design intuition, the performance analysts suggest design interventions with a performance oriented design intuition. This cognitive divide leads to a dipartite design cognition in early phase design. The underlying premise of this research is to support the notion of blurring the dichotomy between conflicting design intuitions through exploring Human + Artificial Intelligence (AI) synergies and their underlying foundational technological requirements with respect to early phase design, to enable intuitive high performance design scenarios with a centralized design cognition where there are no other stakeholders other than the designer and the design environment. With the paradigm shift of other industries towards Machine Learning (ML) and AI, recent research advances in ML and the increasing availability of Big-data in the AEC industry have bolstered multivariate problems like building performance evaluation to a great extent. Design optioneering with instantaneous performance feedback through a ML method called Surrogate Modelling is an upcoming and promising methodology, which delivers feedback based on knowledge through available data, rather than simulation. Also, paradigms in Concurrent Human Machine Interaction (HMI) have explored avenues of augmenting the architectural design process through data-driven approaches. The type of data (input-output pairs) forming the basis for these paradigms depend on the target problem at hand. For early phase performance optimization - especially energy use optimization - Building Energy Model (BEM) forms the primary data. The US Department of Energy defines BEM as a versatile, multipurpose tool that is used in new building and retrofit design, code compliance, green certification, qualification for tax credits and utility incentives, and even real-time building control. BEM is also used in large-scale analyses to develop building energy-efficiency codes and inform policy decisions. A comprehensive BEM dataset that is large and accessible can support the growing interest in ML and HMI research in the high performance building design field. However, common techniques to acquire large BEM datasets like manual 3D energy modeling and simulation, 3D scanning, etc. are very tedious and time consuming. Also, existing datasets are usually incomplete, inconsistent and very difficult to access, owing to data privacy and open-access issues. And lastly, these datasets are fixed, static and cant be easily reproduced for different use case scenarios, nor scalable to adapt to needs. This research aims to tackle this problem by introducing a novel framework to generate custom problem-specific synthetic BEM dataset that generates a user defined amount of context specific 3D early phase building geometries and their associated BEM models, that is suitable for ML and HMI research. Synthetic datasets generated with this framework offer flexibility and customization in the generation process, making these datasets modular, reproducible and scalable. The framework uses the concepts of Generative Design, Geometry Manipulation, Simulation and Computational Automation to build the dataset. The dataset is qualified through the concepts of Preservationism and Sustainability, which are discussed in further sections of this article. The research identifies the importance and multifacetedness of the impact of building geometry on its performance, and demonstrates the application of generated synthetic BEM datasets by developing an enactive, conversational design environment that allows the designer to make real-time sustainable design decisions based on instantaneous machine feedback, for an intuitive, centralized design intuition.

Dynamic modeling and performance evaluation of building envelope enhanced with phase change material under Danish conditions

Interoperability and data exchange within BIM platform to evaluate building energy performance and indoor comfort

In May 2012 “Urban Renewal Law” for reducing the expected seismic risk for existing buildings was published. Depending on this law, existing old buildings should have stability tests for the decision; if it should be demolished or strengthened. This article is mainly concentrating on the earthquake stability and energy performance of a case building regarding the physical and environmental dimensions of urban renewal. Case building is a deficient structure that couldn’t catch the static regulations and so demolished. Regarding the urban renewal process a new building was constructed following the energy performance regulations. In this framework structural and energy performance analysis of the existing deficient building are done to present the conditions first. Then the energy performance of the new building is analysed to be compared with the demolished building. For the static analysis of the existing building ideCAD, for the energy performance analysis BEP-TR 2 programs are used. As a result of this study, the structural performance of the case building is examined to display the need of a new construction and then the development of the energy performance is presented by the comparison in between demolished and new buildings.

This study aims to guide engineers and architects in the implementation of passive heating and cooling strategies, in order to ensure thermal comfort to building users at the lowest possible cost. Proposed passive heating and cooling strategies are also presented. Buildings are a significant energy consumer with a high potential for energy savings.Building energy efficiency can be significantly improved with the use of appropriate technical and cost-effective technologies, with corresponding environmental and social benefits. The application of bioclimatic design techniques is particularly important in terms of a building's energy performance. This word refers to a design that, while taking into account the local environment, aims to provide the best indoor comfort conditions while minimising energy use and utilising available natural resources. Passive heating and cooling systems are systems that use natural sources (sun, wind, etc.) to heat or cool a building without the use of mechanical means. The purpose of passive system design is to improve thermal comfort while saving energy for as long as possible. With the use of passive heating and cooling systems, this study investigates the possibilities of delivering thermal comfort conditions in regions of Greece with different climatic circumstances. The Olgyay bioclimatic charts, which are designed for temperate regions, are used to conduct the bioclimatic analysis. The findings show how passive design strategies affect occupant thermal comfort and provide architects and engineers with design guidelines for energy-independent buildings.

Estimation of building energy performance for local energy policy at urban scale

The term “integrated design” is often used and describes a wide range of activities. The Northwest Energy Efficiency Alliance, through its BetterBricks program, has for several years strengthened the connection between integrated design and improved energy performance in buildings. This article explores integrated design activities and links integrated design to continuing improvements in energy performance in buildings.

Subdivided venetian blind control strategies considering visual satisfaction of occupants, daylight metrics, and energy analyses

Cost-optimal energy performance calculations of a new nZEB hotel building using dynamic simulations and optimization algorithms

Comparative energy assessment of three glazed courtyard roof designs in a cold climate heritage building

Using indicators to profile energy consumption and to inform energy policy in a university—A case study in Ireland

Improved energy performance evaluating and ranking approach for office buildings using Simple-normalization, Entropy-based TOPSIS and K-means method

It is widely recognized that the building sector largely contributes to the total European energy consumption with a 40% influence on the total assessed energy uses. To this regard the EPBD recast Directive promotes nearly zero energy buildings (nZEB) for the public and the private sector as a mandatory requirement by 2020. Given the low energy efficiency of old buildings, concerns about the state of the existing building stock should be seriously considered as most of the energy consumption is attributable to the existing buildings. Additionally, residential buildings are often seen as long-term assets, setting thus a low replacement rate, approximately 1% per year in Europe, of old buildings by new ones. To this regard, larger energy savings can be achieved with the energy retrofitting of the existing building stock, rather than with the construction of relatively small proportion of new high performing buildings. Therefore, the refurbishment of the existing building stock has to be primarily planned and accomplished in order to achieve a timely reduction on the buildings energy consumption. Concerning this, the EPBD recast, as policy driver for reducing European energy use in buildings, has been representing the first and main legislative reference. According to it Member States must ensure that minimum energy performance requirements are set with a view of achieving at least cost-optimal levels for buildings, building units and building elements by means of a comparative methodology framework applied to new constructions and existing buildings undergoing major renovations. The methodology specifies how to compare energy efficiency measures in relation to their energy performance and to the cost attributed to their implementation, and how to apply these to selected reference buildings with the aim of identifying cost-optimal levels of minimum energy performance requirements. A cost optimal level is defined as the energy performance level, which leads to the lowest cost during the estimated economic lifecycle of the building. A measure is considered cost-effective when the cost of implementation is lower than the achievable benefits, during the expected life of the measure. This type of analysis allows defining energy renovation scenario based on their energy and economic optimum. Within the complex scenario described above, this Ph.D. thesis aims to provide a methodology for the definition of energy retrofit scenarios to be applied to existing buildings, based on the use of dynamic building simulation models. The methodology targets the existing building stock given the large energy savings that can be achieved from existing buildings. It builds on an energy and economic assessment of energy efficiency measures applied to different building typologies. The energy and economic assessment are respectively carried out by means of dynamic building simulation and a cost-optimality approach. The cost optimal analysis was chosen for the aim of this study for its systematic approach in defining energy retrofit interventions based on their energy and economic optimum. The term scalable is used for defining the methodology as the studied energy retrofit scenarios can vary depending on the of the study. Two main scales of buildings can be distinguished: building stock or single buildings. When retrofit interventions are studied to be applied to wide portion of the building stock, as for example at national level, representative building models are used. They correspond to reference buildings representative of a certain building typology, construction age and geographic location. Within this thesis, a methodology for their definition was defined and various reference buildings for the Italian context were created. On the contrary, when it is necessary to study specific and customized retrofit measures, a single existing building is modelled. In this case, compared to the case of the reference buildings, larger quantity of data and a higher degree of detail are necessary. These building models are customized based on the existing buildings characterization (e.g. building envelope, system, etc) and when applicable, based also on data from monitoring. To this regards, when detailed information about the building real operation from monitoring is available, the building model need to be calibrated based on measured data. For a model to be calibrated, the building energy consumption predicted by the simulation program, has to match the consumption measured from monitoring. Calibrated models can be used for comparing the baseline situation of the building (calibrated and not retrofitted) with other simulation results relative to the application of building renovation interventions. To this regard, within this Ph.D. thesis, a literature review on the most common calibration techniques currently in use for the calibration of building models was conducted. Additionally two case studies were calibrated by means of two different approaches: a trial and error approach and an optimization-based calibration. For both scale of buildings (building stock and single buildings), dynamic building simulation was employed for the energy assessment. Building simulation application has expanded since mid-‘70s building simulation as an attempt to emulate reality. To date, it is much more common to employ building simulation in post construction or advanced building design phases rather than in early phases. In particular building simulation is frequently used for the prediction of energy savings by assessing energy retrofit interventions on existing buildings. To this regard, given its wide application and the high level of detail of the analysis performed (dynamic analysis), building simulation was chosen within this thesis, as a tool for the energy assessment of buildings and of the relative energy renovation interventions. Finally, the economic assessment of the energy retrofit measures was carried out by means of the cost optimal methodology, as defined by the EPBD recast. The methodology allowed defining energy renovation interventions based on their economical and energy optimum. The Directive requires to define different packages of energy efficiency measures, which can be applied to reference representative buildings but also to single and existing building for energy and economical assessments. The energy assessment of a building can be carried out with analytical or simplified methods, but dynamic building simulation is strongly suggested, as performed within this thesis. For the economic assessment, the global cost method was employed based on the calculation method of the Standard EN 15459 as advised by the EBPD. The global cost method considers, for each energy efficiency measure, the initial investment, the sum of the annual costs for every year (including energy costs) and the final value, all with reference to the starting year of the calculation period. In order to define different energy retrofit solution and set the minimum energy performance requirements, within the Ph.D. thesis, the cost optimal approach was applied to both the considered scale of buildings: to the building stock scale with three reference buildings, and to the single buildings scale with two calibrated buildings. A set of energy efficiency measures was defined and applied to the case studies for evaluating the financial and energy performance gap between the cost-optimal solutions and nZEB levels, respectively. For the building stock, different energy retrofit solutions are defined as final outcomes. Given the use of representative models (reference buildings), the retrofit solutions can be replicated to several buildings, among the same building typology. In this sense, different energy retrofit solutions can be established. On the other hand, for single buildings, the energy retrofit solution studied is specific and customized barely to the analyzed case study

Prefabrication in a controlled, factory setting may improve the energy code compliance and energy performance of modular buildings compared to traditional site-built buildings. To test this premise, the work detailed in this DOE-funded commercial field study (EE0009082) compares the energy code compliance of 25 modular and 30 site-built multifamily buildings under construction in Los Angeles, San Francisco, Philadelphia and Seattle representing climate zones 3B, 3C, 4A and 4C respectively. This dataset includes full data on 20 modular and site-built buildings and partial data on 35 modular and site-built buildings that had started prior to or were completed after the 18-month data collection period. This study also compares the post-occupancy energy performance or energy use intensity (EUI) of an additional 23 modular multifamily buildings and 128 site-built multifamily buildings.

The building envelope plays a crucial role in saving or consuming energy, depending on the type of the envelope and design. Architects and engineers need to consider many issues when working with envelope designs, including environmental issues, aesthetic appearance, occupant comfort, and view; these aspects make the envelope a multifunctional component, thus the integration approach is the optimal method to address envelope design. In the last decade we have witnessed the inclusion of the kinetic envelope in many typologies of buildings. Many scholars believe the kinetic envelope improves the environmental performance of the building. The purpose of this paper is to review the current practice and development of the kinetic envelope and to investigate its role in the improvement of energy performance in buildings.