BEAM Plus assessment is carried out by BEAM Assessors (BASs), who could be in-house staff of BEAM Society Limited (BSL) or external assessors engaged by BSL. External assessors could either be paid or volunteers, depending on the choice of the individuals when they join the assessor workforce. External assessors remain anonymous to project owners so as to safeguard the impartiality of assessment.
Since late 2010, HKGBC has trained and accredited more than 80 assessors through its annual recruitment exercise. The assessor workforce has been maintained at a strength that is adequate to cope with the workload of assessment. As of May 2019, 13 of these assessors are in-house staff of BSL. These in-house staffs have paid an important role in safeguarding the quality and efficiency of assessment.