The clans then play a vital role in the building, maintenance and protection of the bridges, while the diminishing of the craftsmanship and technique caused by urbanization is becoming even more serious these years. This craftsmanship has been passed on down the years from one generation to another by masters teaching apprentices or relatives within a clan following strict procedures.

The construction of these bridges relies on the skilled craftsmanship with a woodworking master directing the carpentry of a team of woodworkers, since the bridges were entirely constructed by hand. This special type of timber bridges in China originating in the Northern Song Dynasty (960–1127A.D.) and now mainly distributed in the southern Zhejiang Province and northern Fujian Province along China’s south east coast. The timber arch lounge bridge, one type of China’s national cultural heritage, refers to the type of bridge with a covered timber lounge house or corridor built on the timber member-weaving arch system. This study contributes to a step forward, from the qualitative cognition to the quantitative assessment, on the way of evaluating the structure safety condition of ancient Chinese timber arch lounge bridges. Moreover, following the proposed evaluation method a case study of Wenxing Bridge is conducted, which could give a better insight into the evaluating process. Special stress is given to the weight assignments during the procedure.

This paper puts forward a universal safety evaluation method for ancient Chinese timber arch lounge bridges. The precondition of planning the preventive conservation of built cultural heritage is the reliable evaluation of the structure safety, which enables the planners or decision-makers to comprehensively understand the complex damaged situation of the bridge and figure out a grading system for the bridge safety state. The timber arch lounge bridge is a special type of Chinese architectural heritage that is widely distributed in the southern Zhejiang Province and the northern Fujian Province.

Wood arch bridge