BIM and energy simulation, defined as the process uses it

BIM is not a 3D picture. It is a digital database of a building that carries, alongside the geometry, the construction build-up and materials of every wall, roof and window.

In Lamit’s process the BIM model is the single source: it is converted into a dynamic physics model, and every equipment investment is optimised against that model. If the architect has no BIM model, we build a clean IFC model from the 2D drawings.

IFC (Industry Foundation Classes) is an open, software-independent file format for transferring BIM models — the common language of the industry.

Any design tool (Archicad, Revit, Tekla) can export IFC. Model objects such as IfcWall and IfcWindow are mapped directly to the calculation nodes of the A-Nodes physics engine, so no geometry or material data is lost on the way.

The E-value (E-luku, kWh/m²a) is the calculated annual primary energy consumption of a building per heated net area. It is the figure a building permit is judged against, and later the figure on the energy certificate.

A static monthly method can produce a plausible E-value and still mis-size the heating system, because it does not resolve thermal inertia or peak hours. A dynamic 8,760-hour calculation gives both the compliant E-value and the hourly load profile the equipment actually needs.

An energy assessment (energiaselvitys) is the wider documentation set required for a building permit: it demonstrates that a new building meets the energy performance requirements set for it. The energy certificate is one document inside that set, and it is also mandatory when an existing building is sold or rented.

Lamit does not issue these as stamps on paper. The assessment is calculated with the same dynamic 8,760-hour model used for the technical design, so the permit documents and the HVAC sizing are based on the same physics.

The climate report (ilmastoselvitys, LCA = Life Cycle Assessment) is the life-cycle carbon footprint and carbon handprint calculation required by the new building act.

When the energy assessment is produced from a BIM model, the climate report is generated from the same data: the model already contains the masses and volumes of every material, so no separate material survey is needed.

Alongside the climate report, the new building act requires a machine-readable building product catalogue: every material and product installed in the building, listed in a structured document.

A complete BIM model already holds this information, so the catalogue is derived directly from it. This removes a manual documentation phase from the architect’s and the principal designer’s work.

A digital twin is a virtual copy of a building that behaves according to the laws of physics. When the architect’s IFC model is connected to A-Nodes, the result is a twin that simulates the energy behaviour of the building for all 8,760 hours of the year.

That twin can then be connected through A+Nodes into the energy network of a city, where it becomes a calculation node instead of a static consumption figure.

Simplified monthly or degree-day methods decouple heating and cooling and rely on empirical utilisation factors. They cannot resolve simultaneous heating and cooling, thermal inertia or the real peak hour that determines equipment capacity.

A-Nodes solves the coupled EN ISO 52016-1 5R1C state-space matrix implicitly for each hour of the year, so both loads are resolved from a single closed energy balance. The engine is validated against the ANSI/ASHRAE Standard 140 test suite.

In a district heating network the return temperature sets the flow rate, the pumping energy and the usable capacity of the production plant. A low, stable return temperature is what makes waste heat recovery and low-temperature production possible.

Static district models have to assume a diversity factor; an 8,760-hour building-level model computes the actual return temperature profile hour by hour, including the hours when simultaneous peak load would otherwise be hidden.

A+Nodes is Lamit’s district-scale layer: building-level dynamic physics connected to network simulation. It computes the district energy balance, return temperatures and simultaneous peak loads from real building models rather than aggregated statistics.

The same engine is offered to cities and utilities as a turnkey service, and to consultants as an expert ecosystem: every correctly calculated building can be integrated as a node in the district model.