У нас дома принято разуваться в прихожей, чтобы не пачкать пол.

У нас дома is a very natural Russian expression meaning at our home / in our household / at our place.

• у нас literally means by us, but very often it means at our place or in our family/household
• дома means at home

Together, у нас дома sounds very natural and emphasizes in our home / where we live.

It is not simply redundant. It gives the sense of in our home, the custom is...

Принято here means it is customary, it is the norm, or it is the accepted practice.

Grammatically, this is an impersonal construction. There is no specific subject like we or people. Russian often uses this kind of structure to talk about customs and social norms.

A very common pattern is:

У кого-то принято + infinitive
= It is customary for someone / in someone’s family/place to ...

So:

• У нас дома принято разуваться
  = At our home, it is customary to take off one’s shoes

This sounds more natural in Russian than directly saying something like Мы обычно разуваемся if you want to emphasize a rule or household custom rather than just a habit.

Because the sentence is describing a general custom, not just the actions of one clearly named group at one moment.

Russian often leaves the subject out in this kind of impersonal sentence. The idea is not we are taking off our shoes right now, but rather:

• this is what people do here
• this is the rule in our home

So принято helps express that meaning without needing мы.

Разуваться means to take off one’s shoes and is very natural in this context.

It is often preferred because it is compact and idiomatic. Compare:

• разуваться = to take off one’s shoes
• снимать обувь = to remove footwear

Both can be understood, but разуваться is the everyday verb Russians commonly use for this situation.

Also, разуваться is reflexive because it describes something you do to yourself: you take your own shoes off.

Because it follows принято.

The pattern is:

принято + infinitive

Examples:

• У нас принято здороваться. = It is customary for us to greet people.
• Здесь не принято шуметь. = It’s not customary to make noise here.

So in your sentence:

• принято разуваться = it is customary to take off one’s shoes

В прихожей is in the prepositional case because it expresses location:

• в прихожей = in the entryway / hallway

When в means in and answers where?, Russian usually uses the prepositional case.

Compare:

• в прихожей = in the entryway (location)
• в прихожую = into the entryway (direction, accusative)

Here the meaning is location, so в прихожей is correct.

Прихожая is the entryway, hall, or entrance area of a home — the place near the front door where people come in, leave shoes, coats, umbrellas, and so on.

So в прихожей means in the entryway or in the hall by the door.

This fits the cultural context very well, since in many Russian-speaking homes, people are expected to take off their shoes as soon as they enter.

Чтобы introduces a purpose clause. It means so that or in order to.

So:

• чтобы не пачкать пол
  = so as not to dirty the floor = in order not to get the floor dirty

This explains why people take off their shoes in the entryway.

Пачкать is the imperfective verb, and here it is the more natural choice because the sentence expresses a general purpose: avoiding dirtying the floor in general.

• пачкать = to dirty / to make dirty
• испачкать = to dirty up / to make dirty completely or as a completed act

In a sentence about a general household rule, the imperfective often sounds more natural because it refers to the activity or repeated possibility in a broad sense.

So:

• чтобы не пачкать пол = so as not to dirty the floor

If you used испачкать, it would focus more on a completed result: so as not to make the floor dirty in a specific instance. That is possible in some contexts, but пачкать is the more neutral and idiomatic choice here.

Пол is in the accusative case because it is the direct object of пачкать.

You ask:

• пачкать что? = to dirty what?
• пол = the floor

Since пол is an inanimate masculine noun, its accusative form is the same as the nominative form:

• nominative: пол
• accusative: пол

So the form does not change, but the case is still accusative.

Russian often uses the singular пол when talking about the floor as a surface in general.

So не пачкать пол means not to dirty the floor as a general household surface, not necessarily one specific floorboard or only one room.

Using the plural полы would sound less natural here unless you were specifically talking about multiple floors or emphasizing several floor surfaces in different rooms.

It can mean both, depending on how naturally you want to translate it into English.

More literally:

• not to dirty the floor

More natural in English:

• so the floor doesn’t get dirty
• to avoid getting the floor dirty

Russian often uses a simple verb like пачкать where English may prefer a slightly different structure.

Yes. Even if the meaning is already known, it is useful to see how natural English may differ from Russian structure.

A closer translation:

• At our home, it is customary to take off your shoes in the entryway so as not to dirty the floor.

A more natural English version:

• At our house, people usually take their shoes off in the entryway so they don’t track dirt onto the floor.

Russian uses an impersonal structure (принято) that often sounds more formal or rule-based than the most natural everyday English translation.

The word order is natural, but not completely fixed.

У нас дома принято разуваться в прихожей, чтобы не пачкать пол flows well because it presents the information in a very standard order:

1. setting — у нас дома
2. general rule/custom — принято
3. action — разуваться
4. place — в прихожей
5. purpose — чтобы не пачкать пол

You could move parts around for emphasis, but the original version is the most neutral and natural.

For example:

• У нас дома в прихожей принято разуваться...

This puts slightly more emphasis on the entryway as the place where the action happens.

It is mostly neutral.

• У нас дома is everyday and natural
• принято is neutral and common when talking about customs, norms, or social habits
• разуваться is everyday vocabulary

So the whole sentence sounds perfectly normal in standard spoken or written Russian. It is not slang, but it is also not overly formal.