Facade Element Segmentation and Window-to-Wall Ratio Estimation Using U-Net

How much of a facade is glass, read from one photograph? A light U-Net labels every pixel of a rectified facade as one of 12 architectural elements (CMP Facade Database, 606 hand-labelled facades), and the window-to-wall ratio (WWR) is read from the labels. On 226 test facades the error is 4.38 points (95 % CI 3.75 - 5.17), against 7.68 for a tuned classical window detector given the true building mask and 4.94 for always answering the training median: better than classical, only modestly better than a constant (R2 0.19). Curtain walls fail clearly. The energy meaning of a WWR error is read from 150 EnergyPlus runs of an earlier project. A web application analyses photographs, rectifies tilted ones and keeps a surveyor's reviews. A teaching prototype, not a survey instrument.

Category: School of Architecture and Planning

Architecture & Planning Project AP04 from ProTechSC Academy, with graphical abstract, video demonstration and project guidance.