Every line is derived from Matthew's five handheld phone pans (33 s, 720p) — per-frame vanishing-point attitude, junction chains, floor-plane projection; no photogrammetry pipeline, no learned model in the metric path. Solid weight grows with the number of independent frames that witnessed the wall. Hollow pulsing vertices and dotted runs are ESTIMATED — the walls must continue beyond what the video saw for the corner to exist. Filled vertices were seen directly. Bedroom, bathroom and the kitchen interior are unfilmed: they are absent, not guessed. Cross-clip assembly is a best-hypothesis fit and is labeled accordingly.