## 1 Introduction  
The incidence of single-person households is steadily increasing [1], and the discourse on providing compact housing to enhance residential satisfaction for single and two-person households continues to gain momentum in South Korea [2]. These residential preferences indicate a preference for personalized living spaces, a trend mirrored in the design of compact and micro-housing units [3]. Such housing types allow for the client's spatial requirements to be actively incorporated into the floor plan, operating within a more modest budget for construction and maintenance costs compared to detached houses [3]. However, clients encounter limitations in providing concrete evidence of their spatial needs, such as spatial configurations or cost estimates, prior to engaging in floor plan discussions with professionals, including architects. This indicates that considerable time and effort are expended by the clients to accurately convey their spatial requirements to stakeholders.  
During the early design stages, non-professional clients, including homeowners (clients), often struggle to articulate their spatial needs--such as size and layout--into concrete building components and envision the final structure without a considerable investment of time and effort, or the aid of architectural experts, such as architects. While floor plans, perspectives, and interior perspective images are provided to assist clients in understanding space, these limited resources necessitate more explicit materials for a comprehensive understanding of spatial arrangements and circulation [4]. Consequently, there are steady needs for creating an effective platform that accurately captures clients' spatial needs right from the conceptual and early design phases. This platform should facilitate a better grasp of spatial layouts, offering a clearer and more impactful alternative to 2D data using 3D visualizations [5].  
Furthermore, relying on 2D information during the initial design phases has proven inefficient for generating construction cost estimates and for the analysis of building performance, including material qualities, physical attributes, and energy consumption [6; 7; 8]. Additionally, clients consistently seek a system that enables an efficient assessment of their spatial needs within budgetary limits. Therefore, it is essential to create a methodology that enables clients to visualize their spatial concepts clearly in 3D during the early design stages, as well as to use these 3D models to analyze building performance, thereby evaluating budget feasibility.  
This study aims to develop a methodology that actualizes spatial requirements derived from sketches provided by clients, encompassing non-expert homeowners, into 3D architectural elements during the initial design phase. This enables a thorough examination of spatial visualization and facilitates an analysis of the associated construction and maintenance costs. The developed framework from the methodology automatically generates a Building Information Modeling (BIM) model from the spatial requirements (sketch information) expressed through a sketching tool. It extracts shape and material property information from the components of the BIM model, directly computing building performance analysis information such as material costs and electricity and gas usage charges. The 3D spaces created through the developed framework can support users in explicitly understanding the spatial arrangement, and the derived building performance analysis information can serve as evidence for decision-making support in budget management.