# House numbers & additions

### How to provide input on house numbers & additions?

As a general rule of thumb:

* A house letter is always a letter and always only 1 character
* House number addition (toevoeging) can be everything in letters or numbers, and can be more than 1 characters

Examples:

1. house letter: A, house addition: 02, `houseaddition` input as string "A02"
2. house letter: '', house addition: 02, `houseaddition` input as string "02"
3. house letter: A, house addition: '', `houseaddition` input as string "A"
4. house letter: '', house addition: '', `houseaddition` input as string ""
5. house letter: '', house addition: 2B, `houseaddition` input as string "2B"