Facade Proportion Calculator
Practice and calculate facade proportion with our free tool. Includes worked examples, visual aids, and learning resources.
Reviewed by Daniel Agrici, Founder & Lead Developer
Formula
Ratio = Width / Height | WWR = Window Area / Facade Area × 100
Facade proportion is the width-to-height ratio of the building face. The window-to-wall ratio (WWR) measures the percentage of the facade occupied by glazing. These ratios are compared against classical proportional systems including the golden ratio (1.618), root-2 (1.414), and harmonic ratios.
Worked Examples
Example 1: Classical Facade Analysis
Problem:Analyze a facade 16.2m wide × 10m tall with 5 windows per floor (1.2m × 2.0m) across 3 floors.
Solution:Facade ratio = 16.2 / 10 = 1.62 (very close to golden ratio 1.618)\nGolden deviation = |1.62 - 1.618| / 1.618 × 100 = 0.12%\nTotal window area = 1.2 × 2.0 × 5 × 3 = 36 m²\nFacade area = 162 m²\nWWR = 36/162 × 100 = 22.2%
Result:Ratio: 1.62 (Golden!) | WWR: 22.2% | Window spacing: 1.46m
Example 2: Modern Office Building
Problem:A facade is 30m wide × 18m tall with 8 windows per floor (2.5m × 1.5m) across 6 floors.
Solution:Facade ratio = 30/18 = 1.667\nGolden deviation = |1.667 - 1.618| / 1.618 × 100 = 3.0%\nTotal window area = 2.5 × 1.5 × 8 × 6 = 180 m²\nFacade area = 540 m²\nWWR = 180/540 × 100 = 33.3%
Result:Ratio: 1.667 (~Golden) | WWR: 33.3% | Floor height: 3.0m
Frequently Asked Questions
What is facade proportion in architecture?
Facade proportion refers to the mathematical relationships between the dimensions of a building's front face and its various elements, including width-to-height ratios, window placement, and the balance between solid walls and openings. Throughout architectural history, specific proportional systems have been used to create visually harmonious buildings. Classical Greek temples used modular proportions based on column diameters; Renaissance architects like Palladio employed musical ratios (1:2, 2:3, 3:4); and Modernists like Le Corbusier developed the Modulor system based on human proportions and the golden ratio. Understanding facade proportions helps architects design buildings that are perceived as aesthetically pleasing and well-ordered.
How does facade proportion affect energy efficiency?
Facade proportion significantly impacts building energy performance through several mechanisms. The overall height-to-width ratio affects wind exposure and structural loads. The window-to-wall ratio directly influences solar heat gain, heat loss, and daylighting — each percentage increase in WWR can increase cooling energy by 1-2% in warm climates. Window proportions affect stack ventilation potential (tall, narrow windows enhance natural ventilation) and daylighting depth (wider windows distribute light more evenly). Floor-to-floor heights determine the volume of air to be conditioned. Facade orientation combined with proportions determines solar exposure patterns throughout the day and year. Modern energy modeling tools integrate these proportional relationships to optimize facade design for both aesthetic quality and energy performance.
References
Reviewed by Daniel Agrici, Founder & Lead Developer · Editorial policy