Applying the NewTREND methodology on the demonstration sites provides many advantages and benefits for the project. Demonstration sites help validate the methodology and tools and give valuable feedback to previous tasks and deliverables, provide integrated project delivery methodology and help market dissemination.
Retrofitting projects, as demonstration sites benefit also from participating in the NewTREND project. Access to the online interface is provided to them to help optimize design and facilitate stakeholder involvement. Through the NewTREND toolset, “as-is” simulations help to evaluate the districts’ and buildings’ current state. Design variations can be created to analyse the different options and to facilitate the decision-making process for the retrofitting’s scope. NewTREND helps to explore funding opportunities and presents business models, as well.
Demonstration sites also had to undertake some tasks for the validation of the methodology and providing feedback. Demonstration site owners had to collect all the relevant information on the existing districts and buildings to be renovated by applying the new approach and support tools proposed, BIM and CityGML models for the simulations had to be prepared, installation of measuring and monitoring instruments had to be ensured. Demonstration site owners had to engage with all the relevant stakeholders involved in each pilot project, including occupants and decision-makers to promote participative project management. The new design methodology, platform and tools had to be applied in the real project design phases. The impacts of the new design approach had to be evaluated according to the indicators. After the completion of the retrofitting, post-retrofitting controlling had to be undertaken through monitoring the occupants’ behavior and performance of retrofitted buildings, by providing post-retrofit measurements or audits based on the behavior of building users and the observation of performance indicators.
For building a model for simulation, each demo site had to create a district scale CityGML model and a building scale BIM model for advanced mode. For the demo sites application of the NewTREND methodology, BIM models are necessary. Building information modelling (BIM) is a process involving the generation and management of digital representations of physical and functional characteristics of buildings. Since BIM is becoming widespread in architectural design and in the construction industry, it was expected that the demonstration site owners would generate an appropriate BIM to provide sufficient data to IES VE simulations.
A detailed description of the BIM model creation methods and experiences and be found in Deliverable 6_3. The main conclusions of the work are:
• Creating BIM with the help of laser scanning enabled fast data collection and comprehensive coverage while providing the required accuracy and resolution. Another advantage of the rsulting point cloud was that it stored all the spatial data of the objects, so without any follow-up on-site measurements it was a good basis for a subsequent reconstruction or further design.
• The BIM models had to be exported in ifc format for building simulations. The BIM models created with the detailedness necessary for architectural planning had to be simplified. Three softwares were used for BIM creating and different methods were needed to export the needed ifc files. For the exporting a methodology were created for each type of modelling software.
CityGML is an open standard data model and exchange format for storing digital 3D models of districts. In NewTREND, demonstration site owners are required to provide CityGML files for the district level analysis and simulation. Current trends indicate that cities and municipalities in the future will have a CityGML-format database. Unfortunately, this is not the case at present, only a few municipalities have prepared the CityGML databases. The implication of this for demonstration site owners was that they had to prepare CityGML files on their own. A step-by-step guide for CityGML creating can be found in Deliverable 6.3 Evaluation of the methodology and tools.
An overview of the BIM and CityGML creating workflows can be found in the following figure.