A new construction element is currently being developed as an innovative building solution: a single prefabricated sandwich panel containing reinforced concrete layers with an insulation core. Experimental testing with varying EPS thicknesses and openings was conducted. The wall with 25mm EPS core showed strong structural performance with minimal deflection. Results suggest insulated structural panels with openings are preferable to conventional walls. © 2024 Elsevier B.V., All rights reserved.