The main portion of our house has a 4:12 roof pitch on a hipped roof. It's a 2-story house, and due to it's siting relative to the street, the roof and roofline are not highly visible.

On the addition, Hubby wants to raise the roof pitch to 6:12 to allow a vaulted ceiling in the room underneath. I love the idea of a vaulted ceiling in that room, but have concerns about changing to a different roof pitch. I'm not sure the extra 18 inches on the interior ceiling peak would be worth potentially 'mucking up' the exterior.

The area in question runs along the house's front elevation -- so left side would be 4:12, right side 6:12. And again, the roofline is not highly visible.

Is this a big architectural no-no?
Or am I being a worry wart for nothing?

If I had a do-over, I would too...
But the main portion is already 4:12...

I don't know why a change in pitch in 2 separate rooflines would be an issue...it all depends on your plans. We have 12:12, 10:12, and 7:12 pitches on our house. It certainly doesn't look awkward.

The first photo shows the drive-up view from the street at ground level, so not much roof showing. Really, not much roof showing from the street at all from any angle.

The second photo shows the view from down the street looking back towards the house.

The third photo is a 'head on' from our across the street neighbor's front door. The planned addition will be on the right side there, replacing the brick wall and brick garage with a structure similar to the one on the left in the same stone, but with more glass in the center. The right side is is where the roof pitch might be different, changing from 4:12 to 6:12. Between the two stone sections, the center area will be mainly glass and will have the front entry.

And the fourth shot is a rendering of the proposed plan. The roofline in the rendering is shown at approximately 6:12 on the right, 4:12 on the left.

Changing pitches isnt as simple as just saying you want a 6 and 4. Overhangs need to be adjusted to make up for the difference in drop between a 4inch and a 6 inch. The original part of the house appears to have a 18-20 inch overhang. In order to match the fascia boards up, you will need to reduce the overhang to 13 3/8 based on a 20 inch overhang originally.

This can also be done by adjusting the heel height of the rafter or truss, or even the wall height to begin with.
It all starts with the overhang and the fascia line and is calculated upwards from there..

Also, with the hip roof, you wont get a two plane vaulted cieling, but a 4 plane hip vault inside instead.

Gorgeous house!

Couldnt agree with you more.
I thought about the application of a dual pitch roof and moving the hips, but what Sweeby is talking about isnt a really a dual pitch hip roof, it is a 6 tieing onto a 4.

Yes, it can be done. but my point is, that there is going to be some thought going into it and I was just bringing that to light in case it hadnt been thought about.

You and I could do it.

And fortunately, my husband can do it also. He's a NARI Certified Remodeler with more than 25 years experience and personally built/rebuilt most of the rest of the house. (The part that isn't pink brick and a 30-year old flat foam roof, that is.)

His plan was to adjust the height of the wall so the facias line up, and a four-plane hip roof inside is what we're aiming for. Need to figure out the best way to insulate it though...

While I've got some experts here and photos posted -- We were considering painting the underside of the eaves the same dark grey-green as the facias. I know it's unconventional -- but what do you'all think about that?

Paint color? Sorry, no help there. hehehe

The concerns were all mine, and all aesthetic in nature. And I really do like to 'lose' a few so I can point them out when there's one I really need to 'win' ;-)

Where the new roof will connect to the existing is directly over where the door is shown in the rendering. That roof will, of course, be the same pitch as the roof it connects to, continuing across the center section. The pitch will change for the block on the right side, and the entire center section can line up on a single plan. Where the pitches change, the ridges won't be parallel -- but otherwise, the change should be pretty invisible.