Fenestration is a complex interplay of characteristics. Getting this equation right will have far reaching and long lasting consequences for building users. Windows provide views outward, daylight inward, and, with the right attention, optimise passive solar gains and natural ventilation.

The role of the designer is to deliver healthy, comfortable and resource efficient internal environments. The advancements in computational modelling, also known as parametric analysis, offers an iterative approach to fine-tuning these requirements.

We provide here a parametric analysis of a worked example for a typical two bedroom apartment, showing how fenestration design can be optimised. From the results below we show that by optimising window sizes we can achieve appropriate daylight amenity, higher Star energy ratings and reduced cooling loads:

SCENARIO A: FULL WIDTH & HEIGHT GLAZING

SCENARIO B: FULL WIDTH & HEIGHT GREY GLAZING

SCENARIO C: REDUCED GLAZING & EQUITABLE DEVELOPMENT

INTERNAL DAYLIGHT FACTOR
Living: DF 1 to 100% of the floor area
Bedrooms: DF0.5 to 100% of the floor area

NatHERS PERFORMANCE
5.8 Stars

COOLING LOAD
47.8 MJ/m2

INTERNAL DAYLIGHT FACTOR
Living: DF 1 to 89% of the floor area
Bedrooms: DF0.5 to 100% of the floor area

NatHERS PERFORMANCE
5.7 Stars

COOLING LOAD
39.2 MJ/m2

INTERNAL DAYLIGHT FACTOR
Living: DF 1 to 99.7% of the floor area
Bedrooms: DF0.5 to 98% of the floor area

NatHERS PERFORMANCE
6.7 Stars

COOLING LOAD
33.6 MJ/m2

SCENARIO D: REDUCED GREY GLAZING & EQUITABLE DEVELOPMENT

SCENARIO E: REDUCED GLAZING

SCENARIO F: REDUCED GLAZING & EQUITABLE DEVELOPMENT

INTERNAL DAYLIGHT FACTOR
Living: DF 1 to 59% of the floor area
Bedrooms: DF0.5 to 25-68% of the floor area

NatHERS PERFORMANCE
7.1 Stars

COOLING LOAD
27.0 MJ/m2

INTERNAL DAYLIGHT FACTOR
Living: DF 1 to 100% of the floor area
Bedrooms: DF0.5 to 100% of the floor area

NatHERS PERFORMANCE
7.3 Stars

COOLING LOAD
18.8 MJ/m2

INTERNAL DAYLIGHT FACTOR
Living: DF 1 to 99% of the floor area
Bedrooms: DF0.5 to 100% of the floor area

NatHERS PERFORMANCE
7.4 Stars

COOLING LOAD
18.0 MJ/m2

This type of parametric analysis is just a sample of the metrics we can add to providing you a detailed understanding of how your design will perform.