If we can see the island in context with the size of the room then it will help. Or if it's an open plan room then post the full floorplan with what other furniture you plan

Agree with Ellie it would be god to see what is on the other side.
I believe though that the recommended gap is 1m min, which I’ve always found to be enough.
Last thought is that if anything, your island looks too short compared to the rest of the run. Good look with the kitchen.

The magic number is always 1m however, with stools, 1.3 sounds like a good distance so you can still comfortably walk behind someone seated and whatever obstacle you then have. 

To prevent the narrow feeling, and give that  solidity that will help, I would put 300x300 base units at either end of the overhang to create a leg cubby. This will make the sides look larger and stop the slightly precarious feel of a floating overhang.  

Good luck
Emily

Thank you for your comments, I don't have the full floor plan but I attach a picture of current state(sorry about the mess). The red like is where the island will be and the yellow dot is where we will have the dining table.

Emily, thank you. We plan to have 3/4 breakfast stools, so the overhang is OK. It is mainly contemplating whether a 2.4m by 90cm island will look too narrow. The kitchen will be 7.3m along the wall. And we want the post in the centre of the island width wise. Hope that makes sense!

If the room is big enough then i'd design the island with shallow depth units on the back and then an overhang (i always use dummy drawer line units for these especially if its a handleless door style so you can open the doors) and that would keep the island in proportion and not look to narrow (like it is now). But this also depends on the worktop you've chosen, as you have a howdens plan you are going to be limited to what howdens can supply and that might be why the howdens 'designer'/salesperson has designed the island like it is.

You could start adding 300 units at each end, but you'd lose one seating position, the other option may be to have 'downstands' where the worktop carries on down to the floor, again depending on your worktop it may need to be a mitred joint, especially if you have a grain/pattern/edge profile. Even then if the room is big enough i'd still have shallow depth units for the extra storage and to make a real statement of the island also have the downstands, lots of quartz worktops are in jumbo sizes and these are 1400mm wide so your island could be upto 2400x1400 so you could easily have the post in the middle with a bit of careful planning.

Thank you lifestyle kitchens. Yes, we will have the waterfall on the island so the stone extends to the floor on both ends. Since we have already started the fitting, we are thinking of extending the overhang on the island to 40 or 50cm to give that extra space on the island.

@Deepak

Depending on your worktop, if you have an overhang of 40-50cm you may need to have support panels/legs/brackets fitted, (anything over 300mm) so have a word with your worktop supplier.

Thank you, will do. Would that be the case even if we have a waterfall on both sides?

@DSB

I'd expect support every 600mm even with the downstands/waterfall, also you say that you have a post in the middle of the island so there would be a joint running through this so that would also need extra support. I'd suggest speaking to your worktop fabricator/installer before you template incase you want to add extra units and also they would of priced for the plan as is and they might want to re quote if the island is made bigger.