The Endrup School, a state school, was built in the early 1970s and is located in Fredensborg, eastern Denmark. Comprising a series of low-rise buildings that offer about 7,000 square metres of indoor space, the school houses 450 students and 52 teachers, who regularly enjoy the beautiful countryside and tranquil surroundings of the park around Fredensborg Palace.  

Until recently, the Endrup School’s two preschool classrooms were severely lacking in both daylight and fresh air – two factors proven to enhance well-being, concentration and, consequently, the ability to learn. The classrooms were dark, façade windows created unpleasant temperature changes, and the teachers and students suffered from poor air quality that caused discomfort and fatigue. The school asked the municipality of Fredensborg for help.

In collaboration with the VELUX Group, the municipality came up with a solution. Installing roof windows equipped with software that enables automatic control and pulse ventilation would provide the classrooms with fresh air without large swings in temperature. “We wanted a solution that ventilated the rooms, lowered the temperature and created better light,” explains architect Knud Jensen.

Spaces transformed by daylight

Knowing the importance of daylight to people’s biological rhythms, well-being, performance, and ability to learn, the design team made natural daylight a focal point of the renovation.

The daylight factor (DF) is a common and easy-to-use measure for the available amount of daylight in a room. It expresses the percentage of daylight available inside, on a work plane, compared to the amount of daylight available outside the building under known overcast sky conditions. The higher the DF, the more daylight available in the room. Rooms with an average DF of 2% or more are considered daylit, and a room will appear strongly daylit when the average DF is above 5%.

To arrive at the ideal daylight solution for the Endrup School classrooms, the design team performed computer simulations in the VELUX Daylight Visualizer 2, a software tool dedicated to daylighting design and analysis.

Before the renovation, the daylight factors in the classrooms where critically low – averaging just 0.8% and 1.1% – and electrical lighting was needed throughout the whole day. The addition of VELUX Roof Windows raised the daylight factors to 3.7% and 5.7%, and the light distribution in the classrooms also became more even.

The change has transformed the workplace, and teachers Kirsten Hansen and Annette Lehmann are delighted. “The room feels bright and inviting now,” explains Annette, and Kirsten adds, “previously, we almost always had to switch on the electrical light but we rarely need that now. In addition, the roof windows enhance the sense of a high ceiling.”

The optimised and controlled use of daylight has cut the use of electric lighting in the renovated classrooms down by 30%. The ample sunlight also provides useful solar gains during the winter period, significantly helping to reduce the building’s energy consumption. 

Ventilation

The new VELUX Roof Windows in the preschool area have effectively solved the problem of poor air, and Annette and Kirsten are pleased with the windows’ automatic control and pulse ventilation. With 28 pupils to look after in each class, they rarely have time to perform a manual air change themselves. Before the rebuilding, they often simply forgot to.

“Now, the software ensures that the air is changed during the breaks and whenever it is needed. There is a CO₂ monitor in the classroom and if the air needs changing, the windows open automatically and close again when the air change is complete, or if it starts to rain,” explains Annette.