Climate Change Weather Files:

A Comparison of Future Weather Generators for Building Simulation

Abstract

Considering the increasing pace of GHG emissions and expected climate changes over the 21st century, the demand for reliable future climate projections continues to grow. This research highlights the importance of incorporating future weather projections into building simulations to ensure long-term occupant comfort and optimize building performance towards decarbonization by 2050.

This study reviews and assesses statistical weather generators (WGs) used to create future weather files for evaluating building performance. The analysis examines these WGs based on format, cost, Global Climate Models (GCMs), downscaling methods, resolution, emissions scenarios, output year, and ease of use. From this review, three WGs were selected to apply in a case study: CCWorldWeatherGen (CCWWG), Meteonorm (M), and Future Weather Generator (FWG). These tools were chosen for their robust climate models and ability to simulate different emissions scenarios. The study focuses on two locations with distinct climates, Chicago (USA, 5A) and Madrid (Spain, 3B), under two emissions pathways— high-emission pathway and middle-of-the-road scenario—projected for 2050 and 2080.

A comparative analysis of the weather generated data emphasizes key climate variables relevant to buildings, such as temperature, radiation, heating and cooling degree days, and comfort hours. These files are used as inputs for energy demand simulations to evaluate how future climate conditions will affect a small office building, which is modelled according to local building codes.

Results show an increase in total energy demand, with variations by scenario. In middle-of-the-road scenarios, demand rises by 5-10% (2050) and goes up to 12% (2080). Under high-emissions scenarios, the increase ranges from 5-14% (2050) and up to 18% (2080). In Madrid, heating demand declines at least 14% in middle-of-the-road scenarios (2050) and up to 42% in high-emissions scenarios (2080). Meanwhile, cooling demand rises by at least 43% by 2050 and up to 117% by 2080. In Chicago, heating demand decreases at least 9% (2050) and up to 35% (2080). However, cooling demand increases at least by 26% (2050) and up to 131% (2080).

These findings emphasize the need to integrate future weather analysis into building design to enhance resilience, energy efficiency, and sustainability in a changing climate.