did you and your designer consider a simple raked ceiling with gables instead of the hip roof? and best location for skylights would depend on your local climate but i'm wondering if they're needed with the excellent northern exposure..but, facing south would have a view of the old roof and north could have better views of the northern sky and potentially tree tops or multiple neighbours roofs up the sloping backyard and would prefer the polished concrete that will act as a passive solar heat sink in sunny weather and concrete is really no colder on bare feet than many other hard surfaces and a rug under seating areas will add colour and warmth in the colder weather

Thanks for you input. I did the plans as I am a draftee but dont do extensions. The reason for sky lights is the existing kitchen dining is dark already so will only get worse and want to add some light in there. You are so right about the view of the roof not the sky and our lovely backyard tree. Think I will change it to the north face. plus you will see them as you walk into the room rather then have to turn around to see them.

Wasn't really sure what you meant about gables though, can you clarify that? cannot really afford to redo the whole roof and this seemed like the most efficient option. Attached the elevations and site so you can see how it sits.

what about one skylight on the northern part of the kitchen roof with another on the northern part of the lounge and will post a plan of the gable roof to show what i mean asap

thanks john. yeah thats what my sister who is an architect said but didnt realise the difference is light quality would be not significant.

how do they insulate slab edges? is that a fairly standard practice?

hails_b_86 slab edges are typically insulated with polystyrene blocks and it is only standard practice in frosty areas. If you are not in a frost zone, don't worry about adding edge insulation.

After a slab is poured on the ground the temperature of the soil underneath eventually becomes quite stable throughout the seasons, so there is less temperature differential across the slab. This helps with thermal comfort.

i meant a roof with a simple skillion shape with southern clerestory windows.

but i'm also wondering how the original rooms will be used and suggest adding kitchen cabinets and furniture to the whole house to have a better understanding of traffic patterns but can't read dimensions to do this