Almost any construction firm can build a project two or three times larger than it normally does. But as the size increases, so does the strain on the company's resources and technical abilities. It can probably get the job done--but can it make a profit?
Undertaking larger projects is a natural part of the growth of a construction company. But when the larger projects are two and three times the previous largest project, contractors are risking their business. Every business has a limit to the rate at which it can grow safely. The problem is finding that limit before passing right through it. The fact is that rapid growth itself is dangerous, not always fatal, but always a risk. The increased risks of taking on much bigger jobs are caused by lack of experience.
Once you have the job you'll want to give it the time it deserves since it's a big part of your volume. But you also need to look at apportioning your time to the other work on hand. Your other projects all may be smaller but they've always been your bread and butter and may be so again.