Equa's simulation technology was invented in the mid eighties at the Swedish Institute of Applied Mathematics in a project for Statoil. The models developed here proved to be both efficient and practical for large-scale industrial simulation.

Some years later, a multi-disciplinary team was formed to develop a full simulation environment based on this approach. Whilst Magnus Lindgren and Lars Eriksson contributed with solid computer science and numerical competence, Axel Bring and Per Sahlin brought with them application perspective and general modeling experience. And so it was that in late 1989 the first prototype of IDA Simulation Environment (IDA SE) was introduced in an Apollo workstation environment.

In the early nineties, Olympic medallist mathematicians Pavel Grozman and Alexander Shapovalov joined the team and several application projects were performed. Amongst them, the first real end-user application (clean room design for ABB Airtech in 1993).

In 1995, the team founded Equa. The company was backed by a significant contract to develop a new generation building simulator based on the IDA technology.

In 1998, the first software product, IDA Indoor Climate and Energy (IDA ICE), was released, and soon thereafter IDA Simulation Environment was made commercially available. Today, the company is owned by the original founders along with other key employees.