How do you tactfully say because mine is better, damnit

I just got a great job working as a designer/architect for a construction company. There is another person (marc) who also designs but doesn’t do the greatest designs. The problem is I spend a few more hours designing a floor plan than he does. So naturally the boss is going to be like why does it take you longer to come up with a design. The boss is somewhat design savvy but not completely. I can’t just come out and say “well because I put more thought into my design and it is a better design than what Marc usually does” How do you tactfully explain, " because my design is kickass and what he does is mediocre?
Thanks for you advice…

Essentially, you’re trying to justify why your designs are better (therefore why it took you longer). If you’re a professionally trained designer (which I assume you are) there are so many ways to justify why you designed something the way you did. Using the language and principles of design, point out the key differences in how Marc does things, and how his designs contradict some basic design principles (which I assume they do). If your designs are better, point out exactly why… ergonomics? safety? aesthetics?

Ultiimately, you’re both working for the same company, so remember that you’re on the same team. Don’t take an “I’m better than you” approach, just use your vocabulary and excellence to prove why your design is better.

Lastly, talk about how much time it takes to think through each aspect of your design… did you do extensive research? did you think about this off-hours? did you put together a better presentation board? There must be valid reasons why you’re taking longer, so try to make those a bit clearer to your management and you should do just fine…

Are you doing unnecessary work. You have to answer the questions that are most important to your boss. Marc is answering those question. Is the above and beyond necessary given the extra expense of time??

Just to flip what Master B said a bit. Perhaps a good tact would be to say something to this effect:

“Well boss, I do take a little longer. I really care about your business and delivering the best possible design for our clients. This motivates me to put in a few extra hours up front so that we can make sure after all those man hours of build time we end up with a result we our proud of and that our client will rave about. I hope that this will help in gaining furure business.”

Right now the boss is probably focused on the “penny”, you working more hours than Marc. Make him focus on the whole “dollar”, you providing more value to clients and increasing his business.