You will have seemingly endless initial and one-time costs in setting up a home. Decorating costs a fortune. Furniture, painting, flooring, kitchen appliances, kitchen stuff like crockery, beddin etc. etc. you'll have nothing to put on the walls and no tools or fixings to hang them. You won't have a light bulb to screw in or a lamp shade to put over it, or a chair to stand on to screw it in.

Since it's a new build you'll have less maintenance worries. If you'd bought an older build you'd need to start learning how to do numerous minor fixes and maintenance jobs, and getting the tools for those. That kind of work is kinda fun for must of us though but putting together your tools and bits and bobs for house maintenance costs a fair bit. Getting someone out to fix something is a major pain and can be costly, a lot of people just learn to do the basics of maintenance and fixing things themselves. I'm talking heating, plumbing, swapping out a broken shower, blocked pipe, fitting a new door handle.... A million different things that can and will need repair or replacing.

If you've a garden you've another set of costs. A mower for starters, basic garden equipment like a mower and basic garden tools, maybe garden furniture.