Here is another plan with the kitchen in relatively the same area as the original.

Any time you move plumbing you incur a greater cost than modifying it in it's current location. How expensive the costs are will depend on where the home main drain is located in relation to the new plumbing, which plumbing materials are used in the home (copper vs. CPVC vs. PEX), local requirements and permitting costs. Not to mention nasty discoveries below ground or behind walls that need to be figured into the contingincies. Moving the plumbing can cost anywhere from 5K up, depending on those factors listed above. I do know of a couple who'se plumbing bill was 35K for their remodel, and that did not even include replumbing the entire house. It did include replacing a septic system that was discovered to be failing.

Additions by themselves are also pretty darn expensive, with kitchen additions running in the 100-150K very easily for even a moderately appointed addition.

live wire oak... So looking at the two plans above, you think that plan #2 would be more cost effective than #1 right? The original kitchen (as stated above) is in the top right hand corner of the diagrams, with the original sink being under the window on the top right.

It also depends upon which plumbing code your under and when your house was originally built.

Under the UPC prior to the late 80's a kitchen sink was connected to an 1-1/2" drain line, but in the late 80's the UPC derated 1-1/2" pipe to a maximum of one DFU. A kitchen sink is rated at 2dfu's so if you move the sink you may have to change increase the kitchen branch from 1-1/2" to 2" all the way from the sink location to the house main drain.

Under both the IRC & UPC moving the sink across the room will require installing an additional vent through the roof, and if you install the sink on the island you will have to install and island loop vent.

If your under the IRC you may be able to get by with an AAV (air admittance valve) but personally that is a poor method of venting and I would be very hesitant to use it.

Hehe lazypup thanks, but that's a lot of technical talk! FWIW the house was built in the 50's.

Let me give you a brief laymens translation of the tech talk.........MORE $$$$$$$

Hi, Unfortunately I don't know how to upload an image like you did, but hopefully you can follow a suggestion:

how about doing something like this:
- Close off the top entry to the kitchen and widen the lower entry. This way you keep the sink and stove in the same place and then place the fridge along the wall you closed off. You can then redo your island, keeping its sink close to the same place. Basically you end up with your "new" kitchen layout, only it is 'mirrored'.

Obviously I don't know what those existing openings lead to or why you want to move the kitchen in the first place, but just an idea.

Good luck.

In the second drawing I was just thinking of sitting down to eat in front of a dirty pile of cooking pots and pans next to the sink. That is why I would go with the first one.
The cost of doing a job is one thing but you also have to think about what you have to live with for years to come. Try and invission yourself working in the drawn up kitchen and the people using it. Trafic or flow patteren, number of steps, storage, etc. are very important in the long run.
By the way where is the dishwasher, if any?