The Preservation of Affordable Housing is adding to its Woodlawn portfolio. The firm acquired two apartment buildings near the site of the Obama Presidential Center for $1.5M and plans to renovate the buildings for low- to moderate-income housing for seniors. POAH is buying the five-story Johnson at 6230 South Dorchester and the six-story Butler Lindon at 6146 South Kenwood from Woodlawn East Community and Neighbors (WECAN), a community development group. The two properties total 105 units, a mix of studios, one-bedrooms and three-bedrooms. Both buildings are minutes from the Obama Presidential Center site in Jackson Park.