This is a question I face almost every time I talk with a customer when quoting a Bathroom renovation. You should always take to opportunity when renovating a bathroom to add ventilation into the design along with heating as in the form a underfloor heating of heat lights this healps with area's that would normally stay wet and reduce the problems of grout getting mould. As for selecting the right size tile this is really a personal choice there are lots and lots of options to pick from when selecting tiles. I always as what look are you going for? fine the look you like and study bathroom designs and take note of the size of tiles tou see in photos make a scrape book of idea's copy ideas pick the best bits. Small tiles can look great on a feature wall but to much of it can make a room fill closed in and to busy on the eye once you have added all your other fixtures and fittings to the mix. 300 x 600 tiles are the far most come tiles we lay where 600 x 600 are great for a modern look. 600 x 600 look great on a floor with 300 x 600 on the walls but I wouldnt suggest having three different tile sizes stick to the same or 2 different styles. it is a hard choice but go with what makes you feel comfortable and scrapbooking idea's is the best place to start. best of luck

thanks to everyone for your helpful comments! I was going to have to pay around $190 for 6 more, but will order them from Beaumont who have a 25% sale on at the moment. I agree that I need to just live with the cost and finish the job properly, but your shortcut suggestions were all really interesting and much appreciated. And archimondo, I'd say it's like having a kangaroo loose in the top paddock.

Large format tiles, such as your 700 x 400 choice look great in large rooms. However with smaller spaces, such as bathrooms in a unit then you really have to plan carefully with your tiler the relationship of the floor waste, the slope, and the grout lines. If your tiler starts setting out the tiles from your entrance hall you may find that there is only one off-centre grout line down the middle of your bathroom , or an awkward transition to make it work with the existing floor waste. A smaller square tile, such as 400 x 400 will be easier to work with, easier to set out, easier to work with slopes, and the position of the grout lines will be less crucial.

Tile selection can have a big impact on the cost of your bathroom reno. The cost of the tiles per sqm is one thing, but did you know that most tilers charge different rates for the "Type" of tile laid large format and or vitrified tiles will cost more to install These are a few hard and fast rules we give our clients when they are selecting tiles for a bathroom renovation 1 - opt for darker tiles and darker grout for the floor - as a wet area light coloured tiles on the ground are harder to keep clean 2 - If you are opting for a feature tile - let it be the hero. That means make the rest of the tiles plain - large format subway tiles give you enough texture without detracting from the feature 3 - always opt for square tiles on the ground - trying to get the correct falls using rectangular tiles will mean you will have extra cuts and the floor will look a mess. The second reason we opt for square format for the floor is because of subway tiles You see, back when everyone was opting for square tiles on walls, it was easy to install square on the floor and get all the grout lines to match. Now most people are opting for subway tiles, you can never get all the grout lines to match, therefore installing square means you dont have to match grout lines as they are different format. If you are installing your subway tiles vertically, then there is a chance you will still be able to get all grout lines to match if you have selected the same sized square format tile hope this makes sense I have added a link to a blog that explains more about tile selection