Contract negotiations have begun between building owners and the union representing over 33,000 residential building service workers in New York City. The talks will determine pay, benefits and working conditions for thousands of doormen, porters and superintendents. The current labor agreement expires on April 20. The Realty Advisory Board on Labor Relations, which represents building owners, has been negotiating with 32BJ SEIU since 1933 and is now representing employers in one of the most unionized sectors of the city’s workforce. Under the current contract, an average doorperson or porter earns about $62,000 a year.