In pre-scientific eras architecture and construction were intertwined. They were often considered one and the same, a Master-builder.
Construction techniques were passed down by oral communication thru apprenticeship.
After the advent of scientific methods of construction the separation of design and construction became the norm. Specialization has its advantages however many are opting for a more efficient and streamlined approach to building.
The DESIGN-BUILD APPROACH offers the following advantages.
1. Ongoing budget control and management
2. Single source accountability
3. Efficient communication
4. Better time and schedule management
5. Quality control
6. Team approach to problem solving
7. Less Litigation
No perfect approach exist, however DESIGN-BUILD's many advantages make it an approach worth serious investigation and consideration!
See link for The Design-Build Institute of America