I vote gable. More classic, imo.

I like the gable too

Tough call, both look good. My very unprofessional assessment of the difference on a home of your design is gables are more causal, hips are more formal - but that's splitting hairs a bit because your home is classic with either. Personally, I'm partial to gables but then we just sold our 1936 colonial with gables :-)

Gable for sure.

I like both. I say hip because I love a hip roof more than anything on any home exterior.

Gable!

Gable, specifically for symmetry and continuity of the front elevation.

gable.

A basic center hall colonial (jazzed up a bit) looks completely wrong with a hip roof. Arched windows need to go as well. A round window above a square, yes. Arched, no. Other than that, it's a classic well done design.

Gable has much more presence from the ground. A lot of times you don't see much of a hipped roof when you're close up. There's a lot of space up there in the attic, it would be a shame to not have natural light in there. If you use the dormers they would be more appropriate with gable fronts.

Gable

Definitely the Gable roofline. It's more traditional, and just looks 'right' for that type of home. I agree with dadereni too about not being able to see a hipped roof much when you're close up.

The arched window with flanking smaller rectangular windows over the front door is a version of a Palladian window that was common in late Colonial houses (late 18th and early 19th centuries). This window feature was also popular on Colonial Revival houses (late 19th and early 20th centuries). However, the house seems a bit lean in other kinds of detailing so it is unclear if it is emulating the older or newer Colonial styles. Hipped and side gabled roofs were common in all of these styles. Hipped roofs usually had dormers especially in the Revival period.

Modern codes require structural beams to support the apex of hipped roofs and due to their shorter ridges they are difficult to ventilate.

To me the 45 degree slope of the front pediment seems a bit too steep for a colonial house especially on the hipped roof where the slope doesn't seem traditional either. Maybe its just the grandness of the pediment and Palladian window with virtually no other colonial detailing (cornices, window heads, door surround, etc.)

Thanks everyone so far for the input, it has been a great help.

Renovator - great catch on the pediment. If we go with the gable roof we can soften that a bit. It is steep to match the pitch of the hips. Which had to be steep to give us the ridge. Frankly, I am a bit concerned about hips in a different pitch than the roof. Do you think if we bring the pediment down to a 9/12 it will be enough or should I go down further. The roof is currently 9/12 but can only go down to 8/12.

The plan is a significant dentil for a cornice, I am really not sure about window heads yet, a decent door surround, etc. I will get that stuff put on later, when I am a little more firm on the plan.

We originally started with a Georgian plan but are trying to pull it to the Federal style. You can see the five, foor and a door influence in the main section. I originally didn't have the bumpout or pediment but the neighborhood has two of those already and I want some differentiation. Also, I have fallen in love with the slightly larger entry. Plus the deed restrictions require a significant pitch (something uncommon in either Georgian or Federal homes) and the pediment helps break it up.

The current pediment slope of 12 in 12 is severe. There houses were modeled after English structures that were modeled after Greek & Roman temples that would be of considerably lower slope. The same goes for the gable or hipped roof slope of a Georgian or Federal (Adam) stye house. However, Colonial Revival houses often have 12 in 12 sloped hipped roofs that are truncated and capped with a very low sloped pyramid roof that can't be seen from the ground. This allows a much larger third floor area, less deep dormers and avoids the oddly French looking tall hipped roof. Show us some photos of the other houses.

1891 Colonial Revival house with some Victorian influences.

photo of same

1759 Georgian house - HW Longfellow home & headquarters of G Washington

"Longfellow National Historic Site, Cambridge, Massachusetts" by Daderot at en.wikipedia - Originally from en.wikipedia; description page is/was here. Original uploader was Daderot at en.wikipedia. Licensed under CC BY-SA 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Longfellow_National_Historic_Site,_Cambridge,_Massachusetts.JPG#/media/File:Longfellow_National_Historic_Site,_Cambridge,_Massachusetts.JPG

Federal house

I like the
gable end and consistency of having all gable roofs. Also as you mentioned the dormers and the windows on the gable will be great
when you decide to finish out the
attic plus you'll have more usable sq footage.

Also I think you said you where going to have the architect add in more architectural details such as lintels, shutters, window sizes, door surrounds etc. Many on this site and elsewhere have recommended the book "Get Your House Right" by Marianne Cusato. It is great for getting the architectural details sized/designed appropriately following time tested Roman and Greek proportions. One risk though is that you can't drive by any new construction without shaking your head at just how many things are wrong.

Compare the pics Renovator posted above with most of today's new construction. IMHO its really the details and proportions that make the house stand out as something worth preserving.