Is it cheaper to completely remodel or build new?

Is it cheaper to completely remodel or build new in Australia, generally it is cheaper to build new $1,500 to $3,000 per sqm for new house 150 sqm = $225K to $450K than completely remodel $2,000 to $4,000 per sqm for full renovation 150 sqm = $300K to $600K if major structural work needed, but minor remodel $100K to $200K cheaper than new build $225K to $450K if structure sound. Completely remodel, also called full renovation, costs $100K to $400K for 150 sqm house with $1,500 to $3,000 per sqm including kitchen $15K to $50K, bathroom $10K to $30K per bathroom, structural $20K to $50K, electrical $5K to $10K and plumbing $5K to $10K, with major remodel involving structural changes $300K to $600K $2,000 to $4,000 per sqm due to demolition $20K, asbestos removal $5K to $10K, hidden problems like termites $10K and 20% contingency $20K to $50K. Build new costs $1,500 to $3,000 per sqm for 150 sqm = $225K to $450K for house plus land $300K to $600K total $525K to $1.05M, with new build having no hidden problems, warranty 6 years structural, modern standards and energy efficient saving $500 per year energy. For example, 150 sqm house full remodel with structural changes $350K versus build new $300K for same size $2,000 per sqm, new build $50K cheaper and warranty, but if minor remodel $150K with kitchen $30K and 2 bathrooms $40K and painting $10K, remodel $150K cheaper than new build $300K. So cheaper to build new if major structural work needed $300K to $600K remodel versus $225K to $450K new build $75K to $150K cheaper, but cheaper to remodel if minor $100K to $200K versus new build $225K to $450K remodel $50K to $200K cheaper, with remodel retaining character and location saving land cost $300K to $600K.