Well balancing out material and costs labour costs is one thing but 2 story is quite a bit cheaper to build ; far less foundation and roofing area. It also simplifies the plumbing and of course is far more energy effective as downstairs heating will also contribute to upstairs heating. PROs can develop on this. And as Curt points out, modular is a very fast and cost effective solution which can allow you to put your pennies into better quality. Be very careful to select a known and competent professional if you go this way though, i don't know about NZ but europe abounds with cowboys ; low costers are to be strictly avoided.

I hope you guys covered the ceiling.

What is the best kind of lighting for a large living/dining room with a gabled/vaulted ceiling? I am thinking of lights at the top of the walls facing up flooding the ceiling so as to reflect downwards?

Hi You will always see the joins if you look closely. There are two trains of thought . One is to make it a feature or try hiding it . The carport ceiling is hardie groove. Andrew