The intrinsic construction project nature of one-of-a kind and the requirement of massive data exchange make collaboration one of the critical factors towards success. However, due to the complexity of multiple phases and multi-disciplinary participants in project life cycle, industry level collaboration in Architecture, Engineering, and Construction (AEC) sector remains a challenge. This paper proposes an integrated solution based mainly on social network services (SNS) and cloud computing. We present a novel platform named Construction Business Social Network Service (CBSNS), which is promising to be adopted as an industrial scope collaboration cloud. We describe its main functions as well as its privacy control mechanism. To better support its deployment as a community cloud, a three-pass load balance algorithm is proposed. The first pass sorts initial virtual machines (VMs) and physical machines (PMs) using bubble algorithm, during which parameters such as hungry threshold are considered. The second pass builds mappings between allocable PM queue and requesting VM queue using first come first served strategy, and groups Non-allocable VMs after designated time slice.The third pass handles possible exceptions when finally such ones existing. The actual time complexity of the algorithm is O(n) .While the commercial implementation of the algorithm is ongoing, the proposed CBSNS has been developed and used in real life application.