در اداره آسانسور هست، اما من از پله ها میروم.

Persian usually puts the verb at the end of the clause, so the sentence feels more like:

In the office, elevator there-is, but I by the stairs go.

That is normal Persian word order. In this sentence:

• در اداره = in the office
• آسانسور هست = there is an elevator
• اما من از پله‌ها می‌روم = but I go by the stairs

So even though the English translation may sound more natural with a different order, the Persian order is completely standard.

در is a preposition meaning in or inside here, and اداره means office.

So در اداره means in the office.

A useful note: در can also mean door in other contexts, but here it is definitely the preposition in.

Also, Persian often does not use articles the way English does, so اداره can mean the office, an office, or just office, depending on context.

Persian does not need a dummy subject like English there.

English says:

• There is an elevator

Persian simply says:

• آسانسور هست
• literally: An elevator exists / is

So the idea of there is is expressed just with the noun plus هست.

Because Persian often leaves the indefinite article unstated.

So:

• آسانسور هست = there is an elevator
• یک آسانسور هست = there is an elevator / there is one elevator

Adding یک is possible, but it is not required. If you include it, it can sound a little more specific or emphatic, like there is one elevator or there is an elevator with extra focus.

هست is a form of to be and here it means is / exists.

In this sentence, آسانسور هست means:

• there is an elevator
• literally, an elevator is / exists

In Persian, هست is often used in existential sentences like this.

اما means but or however.

It connects the two parts of the sentence:

• در اداره آسانسور هست
• اما من از پله‌ها می‌روم

So the contrast is:

• there is an elevator,
• but I take the stairs.

Yes, از often means from, but it can also mean via, through, or by way of, depending on context.

Here:

• از پله‌ها می‌روم means I go by the stairs or I take the stairs

So از is showing the route or means.

This is very natural Persian. Even though from the stairs would sound odd in English, in Persian از works well here to mean using the stairs / via the stairs.

Because English stairs is also usually plural in meaning, and Persian often uses پله‌ها literally as the steps or the stairs.

• پله = step
• پله‌ها = steps / stairs

So از پله‌ها می‌روم literally means something like I go by the steps, but naturally it means I take the stairs.

The plural marker is ها.

So:

• پله = step
• پله‌ها = steps

In careful modern Persian spelling, this is often written with a نیم‌فاصله, which appears as:

• پله‌ها

But in casual typing, people often write:

• پله ها

Both represent the same thing. The version with the half-space, پله‌ها, is usually considered more standard.

می‌روم comes from the verb رفتن = to go.

It is made of:

• می‌ = an imperfective/present marker
• رو = present stem
• م = I

So می‌روم means I go, I am going, or I usually go, depending on context.

In this sentence, the most natural meaning is something like:

• I go by the stairs
• I take the stairs

About spelling:

• می‌روم is the more standard spelling
• میروم is a common simplified typing form

Grammatically, it is the present imperfective form.

In actual use, that form can express different ideas depending on context, such as:

• I go
• I am going
• I usually go

In this sentence, it most likely gives a habitual meaning:

• There is an elevator in the office, but I take the stairs

So it sounds like a usual preference, not just one single action.

Because there is no direct object that needs را.

را marks a definite direct object, but here:

• آسانسور is the subject of هست
• پله‌ها comes after the preposition از

Since پله‌ها is part of the prepositional phrase از پله‌ها, it does not take را.

Yes. A few natural alternatives are possible, for example:

• اداره آسانسور دارد، اما من از پله‌ها می‌روم.
  • The office has an elevator, but I take the stairs.

In everyday spoken Persian, you might also hear:

• توی اداره آسانسور هست، اما من از پله‌ها می‌رم.

Differences:

• توی is a more conversational way to say in
• می‌رم is the spoken form of می‌روم

So the original sentence is correct, but there are other natural ways to express the same idea.