una buena casa or
una casa bien preferred when you want to write "good house"? What is the difference between
Bueno is an adjective, while
bien is an adverb. You wouldn't say
una casa bien since adverbs don't modify nouns, even in Spanish.
Una casa buena describes a house as being nice.
Una buena casa describes a nice house, but the emphasis is on the fact that it is nice.
Note that colloquially you could say,
La casa está bien buena since the adverb can be applied to the adjective.
Una buena casa would be what you would call a superb house; it's not just a good house, but rather a fine house, an indescribably great house. You can spot this extremity in the every day phrase
or, put shortly
Casa bien is not correct unless you want to use an adverb,
bien, meaning very thorough, or well executed, or ironically well.
Una casa bien poblada
A quite populated house / A bit populated of a house / A full house.
casa buena is the correct use, but it's just that... correct. It's not anything special of a sentence now.
The house is good.
The benevolence of the word
buen is hidden behind grammar. Normally adjectives go after the noun, but when you put them in front, translations get interesting and fun.
Sort of like how when you ask someone how the food you cooked was to them and they reply with:
It's fine / It's Ok. / Food is good.
Bien is not
Una buena casacan have also another meaning as a good brand or good store. It's not very common on young people but in senior people sometimes when a brand or a store is trusted the expression
una buena casa is used:
Philips es una buena casa
Philips is perceived as a brand which products are reliable.
Electrodomésticos Pepito es una buena casa
Appliances shop Pepito is perceived as a good store.
I agree with the other answers but I would like to add something else: "Bien" can be used as an adjective in a few occasions (at least in Spain). It means "affluent" or "high social position", or even "snob".
So, "una casa bien" means a wealthy home (not a house in this case). You can use it also to refer to people, "niña bien", for example.
Be careful when using it, though. It is mostly used as a despective concept, because it implies to be a bit "snobbish"