flats, counter for houses, eaves
軒 centers on the projecting edge of a roof: eaves. From there it extends to buildings with such roofs, hence flats or houses, and serves as a counter for houses.
軒 combines 車 (vehicle) and 干 (shield/dry), but the historical origin is uncertain. The modern form may be a simplification or phonetic loan; the connection to eaves is not directly explained by the visible components.
Picture a car (車) parked under the eaves (干 looks like a simple roof line) of a house. The eaves shelter the car, and you count the houses by their eaves.
For ケン, imagine Ken (a person's name) standing under the eaves of a flat, counting houses: Ken -> ケン.
eaves
row of houses
detached house; single house; single building
under the eaves
edge of the eaves; house frontage
one house
each house; every house
next door but one
duplex (house)
barge course
one's next three neighbors; one's next three neighbours
one's nearest neighbors; houses in one's immediate neighborhood; the three houses across the street and the two houses on either side of one's house
in high spirits; elated
several houses
counter for buildings (esp. houses)
to stand side by side; to stand in a row
to stand side by side; to stand in a row
height from the ground to a building's eaves
eave-end roof tile (comprising a convex semi-cylindrical tile and a decorative pendant)
house to house