Am I in perpetual debt to Tom Nook?

When you clear your debt up, Tom Nook asks if you want an upgrade on your house. Larger room, new room, second floor, basement, maybe not in this order.

As a note, the first upgrade once you got your house is a larger room for 198,000 Bells.

For every one of these upgrade, you will be indebted. Once you got every upgrade, you are finally free of Tom Nook's influence!

Note that you're not obliged to get these upgrades. Tom Nook is asking you if you want to upgrade your house but you don't have to say yes.

If you don't want to have a debt, you can still get enough Bells prior to asking the upgrade then when it's done to clear the debt.

To answer more specifically, here are all of the available house upgrades. Each upgrade is optional, apart from the house, which is required for the story. There is also no consequence to not paying back the debt. After the last upgrade, Nook offers free customization changes for life.

• Tent (5k miles)
• House and storage feature (98k bells)
• Larger floor plan (198k bells)
• Room in back of house (348k bells)
• Larger house and external decorations (548k bells)
• Rooms on left and right of first floor (758k bells)
• Second floor (1.2m bells)
• Basement (2.5m bells)