You will need to pour a foundation, frame walls, insulate, and roof just like the box bay will require. (You do not have adequate overhang to do the box as you envision.) Looks like you'll also need to reroute gutters and demolish and rebuild the deck. In for a penny, in for a pound. 7-15K for both projects together. Depends on location and how deep the foundation will have to be.

I don't think it will be attractive. It will be pretty ugly from the exterior in fact. Nor will it give you very much storage by the time the framing is done.

Thank you for replying GreenDesigns.

No, the box bay window will not need a foundation or any changes to roof, gutters or deck. It will look exactly like the photo I posted, which shows how it is supported by kickers/brackets. The photo I attached is from a kitchen forum member named Scrappy25 who has the same 20" eave overhang, so it will look the same. I already got an estimate for $6000 (cdn) for that part.

So, considering it's possible to do the window seat without all the construction work mentioned, I'm wondering specifically about the feasibility of the pantry space. Can it be supported the same way? Can I go to the same depth as the box bay window and add insulation and still be left with 15-18" depth for pull outs or shelves? How will the top of the bump out be handled? (I'm not too concerned about looks as it's in a corner of the deck, will hardly be visible once the new box bay window goes in.)

Any further thoughts, help or guidance from anyone?

Can you post an interior picture of your entire kitchen. Just curious to see the entire space.

Lots of money makes anything possible. Even bad ideas. Walls have thicknesses to them, which you're forgetting, and the only way to have either of your ideas be deep enough internally to be actually useful is to do a real bump out with foundation. However because of the roofline, you need on site professional design help to integrate it. Just a big blob jutting out of the house with some off centered windows is going to look like the amateur design mistake that it really is.

Custom cabinet/shelving inside would be more feasible. What color yellow is in your kitchen/dining room?

Sophie Wheeler, you are wrong about the box bay window needing a foundation. It will have an internal seat measurement of 18 or 19" (which is actually useful) and all of this has already been confirmed by a contractor. So, that idea is not an issue.

I'm not here to discuss the window. I'm asking for help understanding how I can do a similar idea with a closet type space.

geoffrey - thanks. I know I can do a cantilevered bump-out, but I was trying to find out if something on kickers like the box bay window seat is possible.

Vith- I don't know the wall colour, sorry.

Anyone could band saw those 'kickers' as you call them.

The point is that it needs to be framed with 2x4's, insulated, and dry walled.

So if you wanted an 18" wide cabinet, the outside of of the bump out would be 8" wider ( 2 x 3 1/2 + 2 x 1/2 sheet rock).

The problem with the bumpout window as shown is that it is on a load bearing wall, and it will require a header above the window and a header BELOW the window to support the bumpout. Along with the proposed pantry (which should really include the entire space from the window to the corner to be useable and also it does not look odd from the exterior), those are fairly long headers, and you more than likely need extra vertical load support for the headers.

So basically, the contractor cant just rig this up without an engineered plan.

The "contractor"has already fudged on the math to the OP. He'll get creative and rig up some more numbers as well.

"to make up for that lost space,"

How about a window seat banquette with cabinets on both sides of the window?

No, it's not really feasible.

It sounds expensive and unattractive from the outside. What are you planning for dining space? As lazy gardens mentions, could you have 2 tall pantry cabinets flanking the window and forming a u-banquette?