Generating Occupancy Profiles for Building Simulations Using a Hybrid GNN and LSTM Framework

Building occupancy profiles are critical in thermal and energy simulations. However, determining an accurate occupancy profile is difficult due to its stochastic nature. In most simulations, the occupant activities are usually represented by fixed yearly schedules, which are often derived from guides and other similar sources and may not represent the simulated building accurately. Therefore, an inaccuracy in defining occupancy profiles can be a source of error in building simulations. Over the past few years machine learning has become very popular due to its ability to reveal hidden patterns and relationships between data and this makes it suitable for investigating patterns in occupancy data. This study proposes a novel hybrid model combining the Graph Neural Network and the Long Short-term Memory neural network (LSTM) to predict the occupancy of individual rooms on a typical office floor. The proposed Graph LSTM model can produce high-resolution occupancy profiles of an office that are in good agreement with the reference occupancy profiles of the same office. The reference occupancy profiles for this office were derived from an agent-based model using AnyLogic and were not used in the training of the neural network. The proposed Graph LSTM model outperformed other neural networks tested such as the Recurrent Neural Network (RNN), the Gated Recurrent Unit (GRU) and LSTM. When Graph LSTM is compared to the other neural networks tested, there is a range of improvement between 13.5 and 14.6% in the index of agreement, 38.3 and 46.8% in mean absolute error and 34.4 and 40.0% in root mean square error, when averaging the differences over the whole office

Building information model implementation for existing buildings for facilities management: a framework and two case studies

This paper presents the process of implementation of a building information model for managing an existing building, identifying a development framework and documenting the difficulties that occurred during the implementation of the initial stages. The use of building information modelling (BIM) for the design and construction phase of a building has been thoroughly looked into by researchers and practitioners and there is evidence to support that it is beneficial for reducing cost, time and improving communication. A single shared building information model results in a greater accuracy, clarity and consistency of the information available during the life cycle compared to traditional 2D/3D drawings. Yet the potential use of BIM for the operational and management phase (facilities management), besides maintenance schedules and equipment information and location, is still not clearly identified. The UK Government, institutional clients and major private owners are now demanding BIM for new construction and major refurbishment, but given that 70–75% of the UK building stock that will exist and be in use in 2050 has already been built, a significant part of the existing facilities will not have a building information model till the next major refurbishment. This creates a major gap in the built environment, when it comes to having BIM for existing buildings. This paper presents the initial findings of two case studies, where building information models were developed for two existing buildings using a new framework and concludes that minimal BIM skills are sufficient to construct a base building model that can be implemented over time by facilities managers

H-BIM and the domains of data investigations of heritage buildings current state of the art

Heritage BIM can represent many advantages for heritage building documentation, restoration, retrofitting and management. However, the most complicated challenge concerning H BIM is the inevitability of starting at an intermediate point in the asset’s life cycle, which can be much more complex than the relatively straightforward cradle-to-grave model that describes new-build construction (Historic England, 2017). This leads to irregular geometry, non-homogeneous materials, variable morphology, not documented changes, damage and various stages of construction. These challenges put more weight on the surveying, documentation, modelling and visualisation phase within the process of HBIM. Many investigation tools can be used and combined to document and investigate the fabric of historic buildings. This paper reviews the literature and the state of art of the different domains of data that could be included in the documentation and investigation process of the built heritage, in order to assess the breadth and depth by which heritage buildings can be documented. These data can vary from outer geometry survey, to sub-surface materials and structural integrity investigations, to data concerning the building performance, as well as the historic records concerning the building`s morphology over time, which can help to create a more in-depth knowledge about the heritage buildings` status and performance and can create a solid base for any required restoration and retrofitting processes

DIGITAL BUILDING DATA LONGEVITY AND INTEROPERABILITY CHALLENGES IN THE DOCUMENTATION OF HERITAGE BUILDINGS

Abstract. One of the major motivations behind the introduction of BIM (Building Information Modelling) was to mitigate the challenges of interoperability and interdisciplinary interaction between different stakeholders, this is particularly critical in the heritage buildings sector that involves more diverse stakeholders in a wide range of disciplines compared to a standard construction project. A crucial concern in dealing with heritage buildings is the longevity and safeguarding of the digital documentation data that is usually required to be kept as a digital record for the future. This is especially challenging in the digital medium due to the diversity of the software tools, and the fast-advancing and changing software market.In order to assess the needs and challenges facing the heritage buildings sector in terms of data longevity and interoperability and to assess the interdisciplinary interaction needs of relevant disciplines, the authors designed an online survey targeting professionals and academics in the heritage buildings sector and the wider AEC industries. This paper presents the preliminary findings of this survey. </jats:p

Building information modelling-based life cycle assessment (BIM-LCA) for housing estates in Thailand

Abstract Climate change is an important issue with rapidly increasing significance. The demand for housing is rising every year and this can lead to more carbon emissions and environmental impact from the residential sector. Carbon emission over the whole lifecycle of a building are key for sustainability and BIM can play an important role in assisting designers and stakeholders for better decision making, from design to operation, in order to reduce these emissions and improve efficiencies. This research focuses on BIM-LCA at the early design stages with a proposal for BIM-LCA implementation for housing in Thailand, where no formal process for this currently exists. It reviews relevant processes from other countries and proposes a framework for implementation for Thailand. It argues that the government, organisation firms and those involved in Thailand’s construction industry should be more aware of problems surrounding global warming and the importance of sustainably designing housing in Thailand from construction in order to reduce the impact to the environment.</jats:p

Predicting operational energy consumption profiles ::findings from detailed surveys and modelling in a UK educational building compared to measured consumption

This paper presents the preliminary findings from the first stage of a physical survey and modelling case study conducted to obtain modelled and actual energy consumption profiles for a UK multi-storey mixed use educational building (the Bute building at the University of Wales, Cardiff). The purpose of the study is to provide an insight into how accurately current models and software can predict the actual energy consumption in such a building, with a view to informing the development of operational and asset ratings for buildings in the EU as part of the Energy Performance in Buildings Directive (EPBD) Article 7 requirements. The models used in this study were the software tool ECOTECT and the SBEM (Simplified Building Energy Methodology) version of the UK’s national calculation methodology. The study also briefly discusses the potential problems inherent in the use of modelling techniques for assessing the energy performance of buildings. The data obtained through this study enabled predicted energy consumption profiles for both heating/cooling and electrical energy use to be obtained, as well as a UK SBEM asset-type compliance rating. The predicted profiles and compliance rating were then compared to the monitored actual energy consumption profiles obtained over the same period. It was seen that the various modelling approaches gave a reasonable prediction of the gas consumption and a reasonable estimate of the electrical consumption using the SBEM. However, overall it was felt that further case studies would need to be tested to have any confidence in these findings. The relative agreement between the SBEM results in this case study and the measured consumption supports the view that for prediction of electrical consumption then statistically derived numbers, such as benchmarks, are likely to enable reasonably confident predictions of energy use by generic activity type

Thermal simulation software outputs: a framework to produce meaningful information for design decision-making

This paper describes a process used to develop and test a framework to produce thermal simulation post-processed information meaningful to building design decision-making. The framework adopts a user-centred approach in which the building designer is considered the ultimate simulation tool user either directly or indirectly when supported by consultants. The framework supports the building designer's ?modus operandi? and is developed through a set of interdisciplinary research methods. Participatory Action Research, Thematic Analysis and Grounded Theory are used, together with principles from Information Visualization, dynamic thermal modelling and Building Design, following a design approach to problem-solving taken from the discipline of Interaction Design. The various elements of the framework and their connections are derived from analysis of sequences of design actions made by novice designers undertaking complex design activities. Tests of the framework are undertaken through an online questionnaire and five semi-structured interviews with UK architectural design practices