ddarroch Thanks for all the great suggestions. Pity indeed about the directions of the sun and view. Can't change the profile of the block only can try to work out the best based on what it is. Very valid points about the heating VS. clerestory windows. We are in the temperate climate region which keeping warm it’s an issue in winter. We have thought about to have low-e glass in the south facing side but looks like we probably need to have double glazing in places like the north facing clerestory windows like you suggest. No ideas how much more double glazing will cost but certainly we need to include a fair amount into our budget. Agree with having a door separating the living from the back of the house like you said. Much better for heating and sound insulation. Again thanks a lot.

Just a quick update... The guy never got back to me after I offered ( rude!) So the night we got an offer on our house... 2 weeks on market, I emailed 7 House building companies asking if they had homes being completed soon, but not yet on the market. The next morning one rang me at 8.30 and said we have one, a family just pulled out, foundation's have been consented, u can tweak inside a little, move kitchen, add bi folds etc choose colours.. Want to look? Yes if it's west facing backyard... It was but the plan was facing south with the living areas.. Asked if I could flip it.. Yes.. SEND IT OVER 501k Inc patio, drive and path. So we have paid a 3k holding deposit. Just going over plan with my tweaks, and my upgrade costs like ducted heating etc.. Eeek But at least we found one, as all blocks have now been sold in the estate Thank you for all your help. This new plan is only 150sq over brick. But the things we discussed above.. I got!!

Nothing really beats external shading, stopping the air between the glass and the window furnishings from heating up so much in the first place. The glazing of course also matters. Do you have double glazing and/or low-e glass? The internal window coverings are the last line of defence and in my experience there's always some hot air coming around the edges.

@sirisukey. Yes my desk is under window as it is only a small room. It was running along wall under window but moved desk to right angles, facing north, so I could see door and out other window which did increase the problem with sun. I haven’t got around to buying a blind yet as it is a non Standard window size and I wasn’t sure if they were needed. Have windows on three sides and only need blind on the eastern window. Just moving some of my paintings to block the sun at present, It’s the old laundry we changed to study last year.