If you can get under the floors then consider just insulating... we added underfloor insulation, its very easy. There are panels of what looks like polystyrene and they just fit up between the floor joints and squeeze in and stay there. We just bought it from the local hardware store. You don't need to hire anyone to install it or screw it in or anything. You just push it in. This is a similar product, there are many brands. http://www.foamex.com.au/polystyrene-products/expol-underfloor-insulation I read that underfloor insulation gives you a similar improvement to the ceiling being insulated. We have certainly found it made our bedroom much warmer! Well worth it. Insulating under the floor will be a better way to stop the drafts... the timber floors will move and shift and anything you fill the gaps with will crack and fall out soon enough.

Hi Barry, I personally don't think the large blank space lends itself to a piece of art. It's up too high and contrary to your thoughts, it wouldn't be the feature you'd hope for it to be. Besides, the money you spend on a piece large enough, would be better spent on a smaller, higher quality piece mounted at the correct height (eye-level) that would compliment another part of your home. Getting back to the blank space, have you considered using a timber veneer for the wall cabinets? Something that would work with your bench, and then you could use the same veneer as wall panels to continue above the blank space over the cupboards. Perhaps you could even incorporate led strip lighting to give it a little more wow factor. Timber is great because it adds a layer of warmth to the polished concrete and dark cabinets. Good luck, and keep us posted! Would love to see which way you go. Cheers, and have a great weekend. Steve

As timber is a natural material there is sometimes a little bit of shrinkage or expansion with changes in moisture content, or settlement. The filler that the installer has proposed doesn't allow for this movement so it may develop a hairline crack in time, which will be smaller than the existing gap. This is beyond the control of the installer, so he is letting you know before he does it. I would recommend using the filler and living with any tiny cracks that may open up. When your room is furnished and lived in you probably wouldn't even notice. Dr Retro of Dr Retro House Calls

Looking at the photo, the cooktop appears to have silicon under it. Am I reading photo correctly? In my experience, the cook top is put directly onto the engineered stone. There is no silicon required externally.