By Steven Sharp, Reporter: Urbanize Los Angeles – Construction is scheduled to begin this week for a mixed-use development just south of Wilshire Boulevard in Koreatown. The project, called Nexen, will rise from a 1.2-acre site at 2938-2972 W. 7th Street which was previously developed with a parking lot and a single-story commercial building.  Plans call for the construction of a seven-story edifice featuring 228 apartments, 7,230 square feet of ground-floor retail space, and parking for 125 vehicles. Plans call for a mix of studio, one-, and two-bedroom apartments – including 23 to be set aside for extremely low-income households over a period of 55 years. MVE + Partners is designing the contemporary podium-type building, which will stand 91 feet in height.  Architectural plans show amenities including a pool deck and courtyard, a roof terrace, an amenity lounge, and a fitness center.