When the time comes do I need a bigger boiler?
Some things to consider. Age of your home, insulation value now in place and length of warranty required .
Flooring
Tiled, Vinyl or a mix of both.
when it comes to flooring I'm in the mind of picking the most hard-wearing for the given look.
Tiling
Tile size is a question of walls, that being are they flat or are curves, dents and general construction going to cause problems in the finished wall.