Porosity of Balcony fence in Residential Buildings: Balancing Visual Privacy an‎d Daylight Access

10/18/2026 12:00:00 AM

The increasing spatial density in contemporary urban fabrics has intensified the challenge of maintaining residents’ visual privacy in residential units. This study aims to develop a decision-making model for determining the optimal porosity of balcony screens based on geometric patterns. By integrating perceptual experiments using virtual reality (VR) with daylight analyses, the research identifies practical an‎d applicable porosity ranges for the studied context. The findings reveal that the quantified value of the Potential Visual Exposure Index (PVEI) rises with higher porosity levels, while the observer’s distance from the balcony shows an inverse relationship with visual penetration. From a user perspective, lower porosity levels (approximately 10–30%) are suitable for individuals who are highly sensitive to privacy, whereas porosity levels around 30–40% achieve a desirable balance between privacy an‎d daylight access. Porosities exceeding roughly 55% consistently reduce perceived privacy satisfaction. Moreover, in many scenarios, even a 16% porosity was sufficient to meet minimum daylight requirements. Therefore, designers may opt for lower porosity ranges when privacy is prioritized, an‎d selec‎t mid-range porosities (around 35%) when greater illumination is required. Based on the results, a decision-making algorithm was proposed, which using inputs such as street orientation, width, an‎d user sensitivity level suggests the appropriate porosity range. Future studies are recommended to examine wind flow patterns, eva‎luate materials an‎d aperture geometries, an‎d assess the role of vegetation to enhance the comprehensiveness an‎d applicability of the findings.

محرميت بصري , تخلخل حفاظ , الگوي هندسي اسلامي , واقعيت مجازي , شاخص PVEI

Visual Privacy , Screen Porosity , Islamic Geometric Pattern , Virtual Reality , PVEI Index

Mehdi SheikhiNashalji

Fatemeh Mehdizadeh Saradj