The best indoor environment with the lowest possible energy consumption
Using the methodology of Integrated Energy Design (IED), it is possible for the developer, architect and engineer to work around the design of the building. In this way decisions about architecture, engineering, interior, etc. can be made in a systematic process.
The basic principle of IEDs, is to make use of all the passive properties from the architectural choices to create the best possible indoor environment by the building design itself. Use of installations in the building should be minimized and only to supplement the building with light, air and heating/cooling when the passive properties of the building cannot create the effect by itself.
The process is built around a systematic approach with the following 6 steps:

1. Daylight
2. Fire
3. Thermal Indoor
4. Natural Ventilation
5. Mechanical Ventilation
6. Cooling

The steps can usefully be addressed in this order. During the design process it may be necessary to go back in the order of steps as details about the construction work are clarified. The order of steps is based on the following principle:

1 - Daylight
Daylight is the first step. It is determined already at the first sketches of the project, as important decisions about the room depth, room size, disposition of the façade, etc. are made. Daylight is the most efficient light source. Nothing is better than daylight when it comes to color rendering. Daylight does not activate energy consumption. Finally daylight as light source gives the most light compared to the amount of heat introduced to the room. This is especially important for non-residential constructions, which very often create excess heat during daytime. The heat load will be relatively small when a great share of daylight is utilized.

2 - Fire
Strategy of fire is  the second step. This is central to the potential for exploiting natural ventilation in many buildings. The strategy of fire determines how air can move around in the building. Often, this strategy is also used for comfort ventilation and natural ventilation, as smoke and hot air basically moves in the same way in a building. The right design of a building can reduce both capital expenditures on fire ventilation and ventilation for comfort.

3 - Thermal Indoor Environment
Thermal indoor environment in a given building is influenced by a very large number of factors. In industrial constructions it is particularly important to be aware of the daily dynamics of the internal heat load, solar shading, ventilation, etc. Dynamic tools are used in the analysis that can calculate and evaluate several parameters in a building. E.g. accumulation of heat in the constructions, different management strategies for solar shading, heat loads and ventilation. Based on these calculations the strategy for ventilation can be determined, and how much fresh air is satisfactory and when is it necessary.

4 - Natural Ventilation
Based on the analysis of the thermal indoor environment, and the need for ventilation, the possibilities of using natural ventilation in the building are analyzed. The advantage of using natural ventilation instead of mechanical ventilation is that the amount of technical installations very often can be reduced. Natural ventilation also has the potential of saving a large share of electricity, which otherwise would be used on mechanical ventilation.

5 - Mechanical Ventilation
Mechanical ventilation is hereafter dimensioned to cover the needs that the natural ventilation cannot accommodate. Moreover heat recovery, etc. can be optimized. Often two strategies for the building can beneficially be drawn up - one for summer, where natural ventilation may be the dominant ventilation system and one in winter time, when the heat recovery is of importance.

6 - Cooling
Office buildings typically include distinctive rooms that require mechanical cooling - e.g. server rooms. Often, however, it is also possible to exploit natural resources - e.g. night ventilation, where the cold can be stored in the thermal mass and thus reduce the risk of too high temperatures during daytime.