Intangible assets for construction engineering consulting firms are very important for their valuation, because engineering consulting is typical knowledge-based business which creates value based on technical expertise and human resources. This paper presents the intangible asset classification model based on the concept of value creation in construction engineering consulting firm and proposes intangible asset valuation methodology using System Dynamics and survey data. Utilization of the valuation methodology presented in this paper would increase the public awareness of intangible assets in construction engineering consulting firm and, thus, contribute to the growth of the engineering consulting industry by realistic and accurate valuation of intangible assets.