Trj Construction Ltd

TRJ Construction Ltd is a specialist Structural Insulated Panel (SIP) construction company delivering high-performance garden rooms and granny annexes across North London, Hertfordshire, Buckinghamshire and surrounding counties. Founded in 2012 by Costi Tiseanu, who has over 25 years of experience in the construction industry, the company focuses on building better, stronger, and more technically advanced SIP structures. They use 150mm SIP panels for roofs and bases, 125mm structural insulated wall panels, and professional K-Render exterior finishes, with fully integrated electrics as standard.

Their commitment is to quality over shortcuts, ensuring buildings are designed for real, year-round use as home offices, gyms, studios, granny annexes, or independent living spaces. TRJ Construction works closely with structural engineers, building control officers, and planning departments to ensure projects meet current regulations and structural standards. They operate as a construction specialist delivering engineered living space, not just a sales company.

TRJ Construction Ltd offers bespoke garden rooms, granny annexes, and home extensions, emphasizing durability, efficiency, and long-term value. They pride themselves on engineering integrity and provide honest, technical guidance to clients considering SIP garden rooms or granny annexes. The company covers areas including Hertfordshire, Buckinghamshire, Essex, and North London, with a personal commitment from the founder to design consultation, technical specification, material selection, and on-site quality control.