For the most part, connecting with Union Dominion Realty Trust is done online. The mantra is "always open," which translates to smart phone and internet customer service. UDR is one of the largest public apartment real estate investment trusts in the US. It has more than 150 investor-owned community properties throughout the United States and three in Columbia. Apartment seekers can browse through the extensive database, put in living criteria, desired price and other amenities, and the choices will populate. The trust, founded in 1972 as a REIT, boasts 250,000 residents across the country. It is working to expand its involvement in green living programs from its corporate offices to new development.