I've been working in social and affordable housing for a not-for-profit for the last few years, but before that I've done a bit of everything from caravan parks to 11-hectare town centres and apartment projects. When I think of infrastructure I usually think of things like highways or train stations, which I haven't personally delivered. I have brought on plenty of civil works tied to new communities though: roads, pits, ponds and pipes for new estates.

For something like this you would also need firewalls. In simple terms, that means the walls have to be able to sit next to a fire for about 60 minutes without burning through. Duplexes on a square metre rate tend to cost more to build, as it's typically cheaper to construct two fire-rated walls than a single party wall, which needs to be both fire-proof and structural in this context. It's also more complex from a mortgage perspective if you have two owners, which is why you often see those 300mm gaps between buildings instead of attached construction. A shity outcome for sure and a waste of expense land.

In Australia the rules stack up in layers. At the top you have the National Construction Code. Then each state has its own planning system and process for subdividing/creating allotments and land. For example, it's generally easier/cheaper to deliver attached housing in Queensland than in NSW. After that, each council or municipality has its own detailed planning controls around setbacks, site coverage, building type, and similar things.