Simulation vs. Reality: How reliable are dynamic building simulations really?

In our dialogue with our customers, one question comes up again and again: "How accurately do building simulations actually correspond to reality?"

Up to now, we have primarily focused on the quality of our tools. We work with EnergyPlus, the world's leading calculation engine, trusted by professionals worldwide for over 20 years. Combined with our expertise, we stand fully behind our models.

But we wanted to know for sure. We put it to the test and compared our simulations with real measurement data.

The stress test: 6 months, 2 rooms, thousands of data points

For a current project in a modern office building in Graubünden, our client HMQ AG continuously measured the room temperatures in two offices. The goal was to compare the simulation results with the actual measurements. A heartfelt thank you to HMQ AG for the excellent cooperation in this validation.

To achieve the highest possible comparability, we modeled the usage and building technology in the simulation model according to real operating conditions. In addition, we used the high-resolution climate data from MeteoSwiss for the measurement period.

The results: Precision to the point

The results exceeded even our expectations. In both rooms studied, the mean absolute error (MAE) between the measurement and the simulation is less than 1 °C.

To put this value into perspective: Conventional room temperature sensors typically have an accuracy of ±0.5 to ±1 °C. This means that our simulations fall within the measurement accuracy of the hardware.

Comparison of office space: The distribution of the measured values (orange) closely matches the simulation values (green). The Mean Absolute Error (MAE) of 0.9 demonstrates the high reliability of the forecast.

Why this accuracy is crucial for you

The validation of our models is far more than a technical confirmation – it is the foundation for your planning security. In every project phase only reliable results enable truly fact-based decisions.

The precise correlation between simulation and reality demonstrates that dynamic building simulation allows us to reliably prove that comfort requirements are met. At the same time this prevents oversizing of heating and cooling systems. This not only saves valuable technical space but also significantly reduces investment and operating costs.

Consistent results across all floors: In the entrance hall as well, a comparison yielding an MAE of 0.9 confirms the accuracy of the digital twin.

Comfort and safety – even in future extreme conditions

Besides cost efficiency, simulation is an indispensable tool for future-proofing building design. In light of increasing heat waves and tropical nights this ensures that user comfort and thermal comfort requirements are met in the long term.

A suitable strategy for summer heat protection doesn't automatically mean resorting to full air conditioning. We use precise data to develop customized, often technologically streamlined solutions:

• Optimized structural measures and shading

• Effective strategies for nighttime cooling

• Demand-driven and highly efficient controlled cooling systems

Conclusion: Trust data that stands up to reality.

Our validation proves: Dynamic building simulations from BOP

deliver results that are within the physical measurement accuracy.

This is not a theoretical claim. It is based on real experience.

Measurement data proves fact.

For you as a planner, architect or building owner, this means: maximum

planning certainty in dimensioning, in the verification of the

thermal comfort and in the development of efficient cooling strategies.

Do you want to know how your building behaves in the summer?