We are adding an additional garage on to our split-level house. The current attached garage is perpendicular to the house and, of course, sits lower than the house. We are converting half of the garage into an entry/mudroom and adding a double garage on to the current garage. The new garage rafters will be parallel to the house but separated by the current garage. (Is this making any sense?) My question: how important is it to match the pitch of the addition with the current house and garage (4/12). My husband wants to make the addition a 6/12 to provide more storage area. I am concerned more about how it will look.

I should not look to bad. Many roofs do not match pitch of the main roof.
Another method of improving curb appeal without making the front look bad from the street would be to raise the rear wall higher so the back pitch is less. This will allow for more useful storage. Just raising the peak in the middle will do little to gain additional space.

I guess that's why Home Care Club is a good builder and a good home inspector, but not an architect. His suggestion may not look bad from exactly in front of your house, but as soon as you get around the side a little bit, it will look awful, and very much like a mistake.

I'm afraid I can't make any sens of your description. Please post again, and tell us which way the ridges of each roof are running. Most of the split-levels I've seen have the two ridges running in the same direction. Does the upper part of your house have its ridge perpendicular to the street, and the lower part parallel to the street? That is a reasonable possibility.

In that case, if that's true, the new garage would also have its ridge perpendicular to the street, correct? Doesn't the existing garage have a story above it? And the new garage would not? That doesn't sound like a good idea to me. Better if the ridge of the new garage runs the same way as the existing garage...many less roofing details to solve, and a few less pitfalls.

Sorry HHC, but I have to agree with Richard on this one. Two different pitches running together will look pretty bad, I've seen it and it definitely turns your head, but not in a good way. Running different pitches perpendicular to each other usually looks fine, but definitely not "in line" or parrelel with each other, for lack of a better term.

Thanks for all of your input. To clarify (I know my description was difficult), the ridge of the house is perpendicular to the road. The ridge of the garage is parallel to the road. There is not a story above the garage at all. The new addition would also be perpendicular to the road. Does this help?

That's what I thought, but how is it a split=level house? How does the grade run in that area? Does it continue to slope to the side where the garage is? If so, can you drop the garage floor but keep the roof the same? That would give more storage. In any case, it sounds like a job for a good architect...to say much more, I'd have to see the house and the land.