Pushing the boundaries of modular-integrated construction: A symmetric skeleton grammar-based multi-objective optimization of passive design for energy savings and daylight autonomy

Modular-integrated Construction (MiC) is an emerging construction technique promoted in the building sector for high productivity and low waste emission in the construction phase; yet, the standardized modules also bring new challenges, such as balancing passive energy efficiency and spatial daylight autonomy, to the operational phase. This paper proposes a Symmetric Skeleton Grammar-based Multi-Objective Optimization (SSG-MOO) method to formulate parametric MiC envelopes and detailed layout, with the two objective functions being energy efficiency and interior daylight performance in the operational phase. Pareto optima of the SSG-MOO, computed by the Non-dominated Sorting Genetic Algorithm II, are generally verified and analyzed in three levels, i.e., MOO's solution space, SSG layout, and MiC design parameters. A case study of MiC residential building in Hong Kong demonstrated the SSG-MOO method through five new passive MiC designs (i.e., spatial reorganization of three architectural modules, and parameter tuning of the envelops and corridors), achieving up to 0.42% energy savings and 9.71% spatial daylight autonomy improvement compared to the baseline design. The contribution of this paper is two-fold, including a novel and sound SSG-MOO formulation for parametric MiC designs, and offering time-efficient and evidence-based design tactics for MiC designers and industrial practitioners to push boundaries of MiC.

Automated summary

This paper proposes a Symmetric Skeleton Grammar-based Multi-Objective Optimization (SSG-MOO) method for parametric MiC designs, with the objectives of energy efficiency and interior daylight performance. The Pareto optima of the SSG-MOO are computed and analyzed at different levels, demonstrating significant improvements compared to baseline design. The contribution of this paper includes a novel SSG-MOO formulation and time-efficient design tactics for MiC.