The Renovation Explorer - Dynamic modelling v1.0: Description of modelling options and results regarding modelling considerations

The Renovation Explorer aims to support the decision-making of sustainable housing renovations. Based on a dynamic simulation model, it is able to determine the performance of a broad range of performance
indicators (a.o. winter comfort, summer comfort, indoor air quality, heating demand, CO2 emissions, investment costs, total cost of ownership, peak demand of the grid). This model is applied to a wide variety of housing variations and user behavior variations. For each of them, a broad range of renovation measures is being applied, ranging from insulation to ventilation to airtightness to heat pumps and radiators. This allows for the integral optimization of this broad range of performance indicators, to identify optimal renovation packages for every individual house. Recent research in the field of building performance simulation has extensively explored specific areas such as airflow modelling, lighting, energy systems, and user behaviour. However, a noticeable gap exists in the literature when it comes to determining the right level of model complexity and the necessary input data to effectively address all aspects of providing optimal renovation measures. The main scientific challenge that is associated with the development of The Renovation Explorer is exactly this —the need to find the appropriate balance between model sophistication and data requirements.

This report serves a dual purpose. Firstly, it aims to provide a comprehensive overview of the simulation methods employed in this project. Modelling considerations that are explored through simulation experiments in this report include: spatial resolution, construction assembly modelling, thermal bridges
modelling, ground heat transfer and crawl space modelling, ventilation and airflow modelling, solar model, shading modelling, space heating modelling, domestic hot water modelling. Secondly, it establishes the decision-making procedure for the remainder of this study.
This report outlines the purposes and requirements of two simulation models. Firstly, a model is developed to compute billions of combinations involving housing variations, renovation measures, and user behaviour variations. This model is used to find the optimal renovation packages out of all possible combinations of renovation measures for a specific house. Since these types of calculations cannot be done ‘live’, this model is referred to as the “Off-the-Fly” model. Secondly, a model is developed to be integrated into the National
Digital Platform. This model is employed to calculate precise scenarios, enhancing predictions for individual homes and users in real-time. This model is referred to as the “On-the-Fly” model. As both models serve a different purpose, different modelling choices can be made. However, where possible, modelling choices are aligned.

The Off-the-Fly model relies on EnergyPlus, a physics-based model chosen for its extensive open source development, HVAC templates, automation, and flexibility. The On-the-Fly model uses a multizone RC (Resistances and Capacitances) network, BIM (Building Information Modelling) data, simplified ventilation simulation methods, and incorporates user behaviour and NTA8800 based parameters for heating and cooling simulation. Quality assurance procedures of the two models are based on the BEST test described
in ANSI/ASHRAE Standard 140. The report includes an inter-model comparison against validated software, meeting standards for heating and cooling loads. The report also describes a simulation experiment methodology used to determine the appropriate complexity for spatial and temporal aspects, weather
data, ventilation, CO₂, HVAC systems, and occupant behaviour.