[Assessed 85.5%] Apartment building, 5 min from Machiya Station, Arakawa Ward, Tokyo

The source listing gives the address only to the chome, but two entries for the same property on the handling agent's own site both record the lot number "Arakawa 5-chome 42-12". Since the price, yield, land area, floor area, build date and unit count all match exactly, we treated them as the same property and geocoded that lot number using the Geospatial Information Authority address API. On roadside value map 46019, block 42 is uniquely identifiable as the block bounded by Arakawa Fifth Ward Park (block 41) to the west, the Keisei Main Line to the south and a 520C junction to the north-west. The positions of blocks 41, 43, 44 and 45 are consistent with this. The exterior photo we obtained is taken through a clipped hedge, which also supports the site adjoining the park.

We took the 420C (420,000 yen/sqm) on the residential street bordering block 42 to the north-east and east. Arakawa 5-chome spans maps 46019 and 46027, but the 46027 side is the commercial band along Meiji-dori (940C to 1,000C) and the body of the district falls almost entirely within 46019. Residential streets there run from 420C to 520C with a mode of 460C to 470C, so we took the conservative lower bound. On sensitivity: 450C gives 91.65%, the adjacent 490C gives 99.79%, and the 520C to the north-west gives 105.90%. Our figure is the lowest in the district and no street falls below it, so no choice takes this below 80%. That said, the roadside value needed to reach 80% is 392,814 yen/sqm and our 420,000 yen/sqm exceeds it by only 6.9% — worth stating plainly that the margin is not large. We did not take the 510C along the Keisei Main Line to the south, the 520C to the north-west, or the 900C-range bands along Otakebashi-dori and Meiji-dori, all of which are arterial or commercial. The three-year series follows the same street on the same map: 360,000 yen in 2024, 390,000 in 2025 and 420,000 in 2026. The leasehold ratio symbol is C (70%) on every street in Arakawa 5-chome including those around block 42.

All three photos in the source listing are interiors (bathroom, kitchen, toilet), with no exterior and no street view at all. We therefore searched the handling agent's own site, identified the same property by an exact match on price, yield, land area, floor area, build date and unit count, and obtained one exterior photo and a floor plan. The exterior is a detached wooden two-storey building in white siding, with external balconies and a shared walkway serving four units on the upper floor. Nothing within the visible area shows a retaining wall, earth retention or entry steps, and the ground is flat. However, the clipped hedge partly hides the base of the building, so we corroborated with national 1 m laser survey data, measuring the site and seven surrounding points: 1.9 to 2.3 m above sea level, with a maximum range of 0.4 m across roughly 80 m. This is flat alluvial ground on the Arakawa lowland, leaving no room for a metre-scale retaining wall or step.

Given the 66.8 sqm plot and 84.76 sqm of floor area close to the station, we checked carefully for party-wall construction. On the north side the neighbour is a cream-coloured rendered two-storey building; the two roof lines end separately with sky visible between them and a utility pole standing in the gap. On the south side this building's balcony terminates at a mullion, with its own downpipe running down beside it, while the neighbour's exterior wall is set back on a different plane at a different eaves height. Neither side shares a wall, so this is a free-standing building. The frontage road itself, however, does not appear in any photo, so the direction, width and any setback of the road remain unverified.

We took the 66.8 sqm as the effective land area in full, for three reasons. The source's own guidance states that land area is shown net of private roads. The handling agent's site records no private road burden area. And the exterior photo shows no access strip or tandem parking, with the site sitting inside a regular block on the roadside value map. Neither source mentions a sloped portion, and our elevation measurements found a maximum difference of 0.4 m.

The land is held in freehold, in an urbanisation promotion area. Sources disagree on zoning — one records "quasi-industrial" and another "neighbourhood commercial" — and none of them state the building coverage or floor area ratio. The frontage field is also blank, leaving the direction, width and any setback unknown. Nothing anywhere mentions non-rebuildable status, a proviso road, a cliff ordinance or leasehold. With four units and 84.76 sqm of floor area, Article 5 of the Tokyo Metropolitan Building Safety Ordinance (which requires a 3 m site passage for row houses of ten or more units or over 300 sqm) does not apply.