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Staircase-style blocks 12 by 8 meters (2-room ~40 sqm), 16 by 8 meters (3-room ~50 sqm), and 22 by 8 meters (4-room ~70 sqm).
Corridor-style blocks with 6 or more units per floor, 9-13 meters width, most common unit types:
2-room 1-bay (4.5 m long)
3-room 2-bay (6.5 m long)
4-room 2 bay (7-8.5 m long)
4-room 3-bay (10 m long). example
Staircase-style blocks with 2 units per floor, All 11 to 14 meters in width, most common types:
3-bedroom 2-bay, 84 sqm (18-21 m long) example, example 76 sqm
3-bedroom 2 bay, around 105-110 sqm (20-22 m-long) example, example 2.
3-bedroom 3-bay, around 105-110 sqm (22-24 m long)
4-bedroom 3 bay, around 140-150 sqm (26-28 m long), example.
4-bedroom 4-bay, around 150-180 sqm (30-32 m long) example.
5-bedroom 4-bay, around 200 sqm (32-36 m long)
4-room are dominant, followed by 5-room ones. All 3-room and smallest 4-room have a single bathroom.
Selection of floor plans and other stuff found during my study
I found numerous floorplans by Google searching 방수:4개 (you can change the number, from 1 to 6 bedrooms).
Also by searching apartment name in Korean (I do not speak korean, but I copy apartment names from Panoramio photos found in Google Earth, or from Wikimapia).
Corridor-style floorplans, from 2-bedroom to 4-bedroom.
Set of 4 apartment types, 3-bedroom to 6-bedroom, floorplans.
Set of 8 apartment types, 74 to 154 sqm, floorplans.
Another 8 apartment types, from 108 to 314 sqm, floorplans, weird entry corridor.
Daewoo Marina Apartments is showing lots of floorplans, 2-bedroom to 5-bedroom.
Lotte Castle Premier Apartments, 9 unit types ranging from 105 to 238 sqm, floor plans.
Samsung Tower Palace, tallest building in Korea, is showing floorplans too.
A Youtube channel containing lots of videos inside apartments alphabds. Sadly, most apartments are unfurnished or furnished for showcase, I wished to see how koreans actually use each room, but found this one, cluttered with… all people’s stuff!
There are also bigger apartments, usually only 1 block in the complex, 5/6-bedroom, examples:
Hyundai Apt block 76, 41 m long and 14 m wide block segment with two apartments about 270 sqm, according my measurements in Google Earth (possible floor plan http://blog.daum.net/kyasin77/801)
Lotte Castle Premier Apartment, block 110, 238 sqm, floor plan & interior photos.
Imaechon Cheong-gu, bloc 603 & 614, 48 m long and 13.5 m wide, 69 pyong = 238 sqm, http://blog.daum.net/stylings/519
Buyong E-Green Town Apartment, one of my favorites (probably due to nice shape viewed in Google Earth).
Found its blog page and the plan of apartments. Notice that there are 5 apartment types, 3/4/5-bedroom, most have 4 bedrooms, size range 105-215 sqm, try estimate the average size of apartments! It’s huge anyway!
Again, why does koreans need so much space? There may be couples without children, they really need 3-4 bedrooms!?
http://www.youtube.com/watch?v=AF_5peDRTpA video of apartment evolution in Korea compared with France and other countries. So sad that isn’t in english.
http://blog.daum.net/k1004/15668146 LG apartment 125, 160, 195 sqm
http://blog.daum.net/lglotte4300/557 123-226 sqm
http://blog.daum.net/autokoo/731 Jamsil (10-storey area), built late 1970s, floor plans and plans for reconstruction