Cultural sustainability in fashion design requires approaches that move beyond the visual reproduction of cultural elements towards situated interpretation and meaningful transformation. Our previous studies on culturally oriented product design (COPD) developed a metaphorical mapping method to translate cultural inspiration (CI) from both tangible and intangible culture into contemporary product designs (Authors et al., 2025; Author, 2025). However, these studies focused primarily on the relationships between cultural characteristics and design outcomes within field-based research, without attention to how cultural interpretations are grounded in fashion design with authentic cultural settings. Addressing this gap, the present study conceptualises Guizang (归藏) as a culturally intensive and participatory approach to fashion design. Through a university-enterprise collaboration across Kunming City and the Xizang Autonomous Region, China, we employed an ethnographic design approach to conduct design-based research for cultural heritage in Xizang, in which field-based observation, garment design and production, presentation, and reflection remained interconnected. The materials, including photos, sketches, textual notes, recorded verbal explanations, and garment designs, were collected and analysed. The findings further demonstrate how field-based cultural immersion enhances designers’ contextualised fashion design. The study, therefore, extends earlier COPD research by positioning Guizang as a culturally contextualised approach to culturally intensive fashion design.