CASE C42 · JP · 2024
Tokyo Metropolitan Housing Supply Corporation: tethered infrared drone facade survey of a 32-storey public housing tower
JKK Tokyo trialled a tethered infrared drone facade survey on a 32-storey public housing tower in Koto-ku. Cracks and chipping were found well and tile delamination was mostly detected, but heat from railings and sealant caused false positives. The weakly sunlit north face could not be validated, so follow-up tapping is still needed.
| Owner | Tokyo Metropolitan Government (Toei housing), managed by Tokyo Metropolitan Housing Supply Corporation (JKK Tokyo) |
| Provider | — |
| Location | Toei Shinonome 2-chome No. 2 Apartments, Koto-ku, Tokyo, Japan |
| Aircraft | Small drone (about 900 g) on a two-point tether system |
| Sensors | thermal infrared, RGB camera |
Before
Full tapping inspection of tiled facades roughly every 10 years, usually from gondolas, which are often impractical on 60–110 m towers.
With drones
Following the March 2022 change allowing infrared drones, floors 23–32 on all four faces were flown about 4 m from the wall in 96 flights over five days, with a two-point tether, cordoned ground area and spotters.
Outcomes
| Metric | Value | Basis |
|---|---|---|
| survey effort | 5 flying days, 96 flights, 4 faces; seven-role crew | Reported |
| surface defects | chipping and cracks identified well in visible images, checked on site | Reported |
| tile delamination | generally detected from thermal differences, with some false positives on sound areas | Reported |
| accuracy / cost | not quantified | Reported |
Caveats & limits
- False positives were caused by sun-heated metal railings, black sealant and different heat storage in steel, rebar and precast elements; expert interpretation and follow-up tapping are still needed.
- The north face had no detected delamination, so weak-sun accuracy could not be validated.
- Single-building trial of public rental housing (not an owner-occupied condominium); rooftop louvres had to be removed to fix the tether, and flight plans must be tailored per building.
Sources
- 超高層住宅におけるドローンと赤外線を用いた外壁調査の試行Tokyo Metropolitan Government Bureau of Finance (paper by Tokyo Metropolitan Housing Supply Corporation) Full text read
Sources checked: 2026-10-22