# Weather Files for the Calibration of Building Energy Models
## 2 Methodology
### Case Study  
To implement the methodology proposed in this paper, publicly available data from the Annex 58 IEA-EBC [35; 36], Reliable Building Energy Performance Characterisation publication, were adopted. Full-scale dynamic measurements were used for the generation of the energy model and for obtaining the calibrated model. The Annex 58 project started in 2011 and ended in 2016; it was developed with two main objectives: to develop common lines of action that offered improved system performance to obtain energy models, and to achieve quality BEMs capable of reproducing the thermal characteristics of buildings. Regarding the outcome of the Annex 58 project--a pair of houses (Figure 5), i.e., N2 and O5, located at the test site of the Fraunhofer Institute for Building Physics, Holzkirchen, Germany, was fully monitored with research-grade equipment, and data were made available for the public. Therefore, the Twin Houses were selected in the case studies due to the transparency and the quality of monitoring data. The houses do not have any elements nearby that could cast a shadow on them in the summer--the season in which the study was carried out. Both houses are located a few meters away from each other. A single weather station was set up for both buildings so that the weather files generated by the on-site sensors were the same for both houses. The station was located about 25 m from N2 and about 45 m from O5. This single station served both houses because it reliably reflected their meteorological environment due to the low density of the site. The recommended distance at which the weather station should be located will be the distance necessary to capture the meteorological characteristics of the building environment. For example, in a high building density environment, such as a large city, the optimal placement of the weather station would be as close to the building as possible, but this distance can be increased if the density decreases and there are no obstacles that make it difficult to clearly obtain the weather characteristics of the building environment. Figure 4: Weather explanation and objectives of the research. The buildings are single-family homes with three floors: attic, main floor, and basement. Each has a free height of 2.50 m. The study focused on the main floor, as was done in the project described in Annex 58. The main floor has a configuration of two bedrooms, a corridor, a bathroom, a kitchen, a living room, and an entrance. The monitoring conducted in Annex 58 involved five periods (Table 1) in terms of thermal dynamic characteristics to reflect the common conditions of the buildings. Each period had bespoke configurations, and the BEM must have been capable of responding to reality in terms of the energy consumed and the temperature reached. The proposed period began with the first (initialization), lasting three days, in which a constant interior temperature of 30 \({}^{\circ}\)C was maintained in the buildings. In period 2, with a seven-day duration, a constant temperature of 30 \({}^{\circ}\)C was maintained inside the houses. In period 3, which lasted 14 days, the energy was introduced through the living room radiator at random periods with a randomly ordered logarithmic binary sequence (ROLBS). This sequence was created in the EC COMPASS project. Its goal was to give the same influence to all energy inputs that affected the BEM. The energy inputs and the free oscillation intervals were selected so that they did not stand out from each other and were mixed in a quasi-random way. Using this form of introducing power into the models, there is no relationship between the energy introduced by the HVAC systems (or heating system) and the solar energy. The energy model must be able to reproduce the internal temperature that this energy produces.