The tool for it
VICUS Buildings Beta
Dynamic building simulation with IFC, DXF and PDF import, multi-zone room balance and verification per DIN 4108-2.
with VICUS Buildings
Summer thermal protection per DIN 4108-2 – verified by simulation.
When the solar-gain coefficient method is not enough.
The dynamic simulation determines the overheating degree hours per room and represents shading, thermal mass and night ventilation in a time-resolved way – often the route to passing where the simplified method fails.
Starting point
When the simulation verification becomes necessary
When the simplified solar-gain coefficient method is not passed, only the simulation verification per § 8.4 DIN 4108-2 reaches the goal. The methodical fundamentals are covered in our article on summer thermal protection per DIN 4108-2.
- High glazing fraction Glazing fractions above 50 % usually make the simplified method fail.
- Corner rooms Glazing facing several orientations increases the solar gains.
- Top floors Inclined windows and little thermal mass favour overheating.
- Summer climate region C In the warmest regions the requirements are strictest.
Approach
Four steps to verification
- Step 1 Model the building Read geometry from IFC, DXF or PDF, or build it directly in the 3D environment. Glazing, orientation and shading become the basis of the thermal model.
- Step 2 Set boundary conditions Parameterise summer climate region, usage profiles, shading (FC value) and night ventilation – from bundled databases or project-specific.
- Step 3 Simulate overheating degree hours Calculate the operative room temperature hour by hour across the full year and evaluate the overheating degree hours per critical room against the limit value.
- Step 4 Document the verification Document that the verification per § 8.4 DIN 4108-2 is passed and export it as a traceable, customisable report for approval.
Result
What you end up with
A verification that evaluates measures instead of assuming lump-sum values.
- Overheating degree hours
- per critical room, against the limit (residential: 1,200 Kh at 25 °C)
- Comparison of measures
- Shading (FC value), thermal mass and night ventilation in combination
- Summer climate region
- Assessment for region A, B or C per DIN 4108-2
- Geometry import
- IFC, DXF and PDF instead of double modelling – glazing and shading taken from the design
- Report
- traceable and customisable, for approval
Frequently asked questions
When is a simulation for summer thermal protection required?
The simulation verification per § 8.4 DIN 4108-2 is required when the simplified solar-gain coefficient method is not passed – typically for glazing fractions above 50 %, corner rooms with glazing facing several orientations, top-floor apartments or buildings in summer climate region C.
Which metric does the simulation provide?
The dynamic simulation determines the overheating degree hours (Kh) – the sum of how far and how long the operative room temperature exceeds a limit temperature. For residential buildings a limit of 1,200 Kh at 25 °C limit temperature during occupancy hours applies.
Which measures can I evaluate in the simulation?
External shading, thermal mass and night ventilation are represented physically correctly. This lets you deliberately size which combination brings the overheating degree hours below the limit – instead of relying on lump-sum assumptions.
How does the simulation differ from the solar-gain coefficient method?
The solar-gain coefficient method is a simplified, static check. The thermal building simulation calculates the building dynamically across a full year and represents thermal mass, night ventilation and shading strategies in a time-resolved way – so it often passes even when the simplified method fails.