Module 9 - Points to Ponder

Can you guarantee that the completed building will match the performance predicted by the analysis in its day-to-day operations?

• No, the energy performance model provides an estimate of the actual day-to-day energy usage intensity of the building. Uncertainty is introduced in the variability of: building material thermal properties, operating schedule, fluctuating occupancy, and weather...just to name a few factors of uncertainty. If the surrounding environment can also be modeled (for shadows and wind), there could be a more thorough thermal analysis done on the exterior of the building. The interior power consumption of the building can be modeled with increased accuracy if provided more data for the specific building usage type, or if the operations inside the building are easily predictable (like a factory).

What level of detail should be included in a 4D simulation?

• 4D simulation should include as much detail as is necessary to provide the desired resolution of timeline. A weekly or monthly timeline should typically suffice for material deliveries and installations (for example, concrete takes ~4 weeks to cure). Timelines with finer detail can be used for managers to visualize and manage daily operations.

How can model-based quantity takeoff improve the design process?

Model-based quantity takeoff estimates can aid designers in identifying areas in need of cost improvement, or deciding between different structural design options among stakeholders early in the design process.