Microscale walkability assessment has become increasingly important for understanding how detailed street conditions shape pedestrian experience, especially in historic districts where constrained spatial forms and mixed patterns of use complicate conventional evaluation. This paper develops an analytical framework that links physical street features, perceived qualities, and overall walkability. Accessibility, safety, comfort, and attractiveness are treated as interrelated dimensions of perception, while environmental indicators are operationalized at spatial ranges corresponding to the ways pedestrians encounter them. The framework is initially implemented in Pingjiang Historic District, Suzhou, by integrating on-site ratings with street level 3D point cloud data acquired through mobile mapping, together with geospatial data. Preliminary mapping reveals clear differences among streets and continuous clusters of high and low scores, indicating that perceived walkability varies spatially across the district. Future work will complete the extraction and spatial matching of environmental indicators and examine how physical street features shape perceived accessibility, safety, comfort, and attractiveness, and how these perceptions contribute to overall walkability.