The symbols represent individual buildings shown on the 1:25,000 topographic map based on the 1969 survey. Most symbols represent traditional Malay houses, but some represent clinics, airport and other commercial buildings.
Based on a pixel count, there were about 3,400 groups of pixels each representing a building. An average ground area of 75 m2 per building would give a total area of buildings of about 0.25 km2. To obtain the total residential-commercial area, the area of buildings should be multiplied by a factor to account for infrastructure (environs of the buildings, roads, bridges, storm drainage). For a rural area such as Bayan Lepas in 1969, a multiplier of three might be sufficient, allowing one-third of the area for buildings, one-third for building environs, and one-third for infrastructure. Multiplying the area of buildings by three, the total residential and commercial area would have been about 0.75 km2, not counting the airport, which was estimated separately.
