Portland Public School board members unanimously authorized spending $16 million in bond funds to purchase a landmark building in the Albina neighborhood to house a future Center for Black Student Excellence, a key milestone after five years of delays.

Tuesday’s vote allows the school district to shield the building in question — the distinctively curvaceous One North development at the corner of North Fremont and Williams avenues — from other buyers while officials perform due diligence to investigate whether it is the right fit for the school district.