Employers may take you on as a trainee if you have 5 GCSEs at grades 9 to 4 (A* to C) and 2 A levels, in subjects like maths, science, IT and technology.
They may accept equivalent qualifications in engineering or construction, for example the Level 3 Advanced Technical Diploma in Constructing the Built Environment. Level 3 courses in 3D design could also be useful.