+1, another angle is to not double glaze rooms that are not generally lived in: storage room, bath room, etc. Or not to double glaze rooms that won't affect heating and cooling as much. However would these windows and doors different between double glazing and single glazing annoy you visually? Another consideration to double glaze now is that cost is minute compared with the whole house build cost, and you will have to pay a fair bit more in the future to get the rest removed and double glazed. I have all windows and doors for an old house double glazed with uPVC frame, and am pretty with them. Previously, when I was in an apartment next to a major road, only the bed rooms were doors were replaced with double glazing doors for noise reason.

Painted Murals done professionally are extremely expensive dependant on size wall texture and the preparation needed prior to being painted. If the space is small you could try and do it yourself but if the pace is larger they really need to be done professionally. Have you considered using a large photgraphic print instead. You can pick any landscape or image you like, you can get them done on canvas or in a wall paper and in almost any size. eazywallz has some great examples

Get in a really competent tiler with great references, and ask him about a really level base for tiles there. (Without it you will get cracked tiles. ) Non -slip tiles to suit your house will solve the slipping problem.

kitchen to south any day of the week....I'd also go further to suggest that possibly the building could have been designed to have the kitchen hard to the south boundary that would have opened up more north light opportunity and better use of the (unusable) side space behind the kitchen. You'd still need a light court for the bedrooms etc...& possibly by doing this the future pool could have been flipped and oriented more to the north/west corner and the net effect would be having more options/flexibility for the outside space, & also possibly alfresco area located on the north which is always better than to the west, so alternatively an extension that is more streamlined in design, following the line of the existing building rather than kicking out, I can see immediately that this type of design strategy would bring some arguably clear benefits on a number of levels .....not sure how far down the track you are (looks like still in concept/sketch design stage) may I add that it's always cheaper to consider re-design on paper rather than regretting less than ideal outcomes after they're built...... anyway food for thought........always consider the options and maintain an open mind...it's always ALL in the design Best of luck Cheer PD :)