Вопреки ожиданиям, опенспейс оказался тихим.

Вопреки means contrary to, despite, or against in the sense of going against what was expected.

A very important grammar point: вопреки requires the dative case.

So:

• ожидания = expectations
• ожиданиям = to expectations / contrary to expectations

That is why the sentence begins with Вопреки ожиданиям.

Because вопреки governs the dative, and ожиданиям is the dative plural form of ожидание.

Case breakdown:

• nominative plural: ожидания
• dative plural: ожиданиям

So the phrase literally works like:

• вопреки ожиданиям = contrary to expectations

This is a very common fixed pattern in Russian.

The plural is the most natural choice here because Russian, like English, often talks about expectations in a general sense using the plural.

So:

• вопреки ожиданиям = contrary to expectations is idiomatic and common

The singular вопреки ожиданию is possible in some contexts, but it sounds more specific, as if there were one particular expectation. In this sentence, the plural sounds much more natural.

Опенспейс is a borrowed noun from English, referring to an open-plan office or open office space.

In Russian it behaves like a normal masculine noun ending in a consonant:

• nominative: опенспейс
• genitive: опенспейса
• dative: опенспейсу
• etc.

In this sentence it is the subject, so it is in the nominative singular:

• опенспейс оказался тихим

Оказался means turned out to be or proved to be, not just was.

That is an important nuance.

Compare:

• Опенспейс был тихим. = The open-plan office was quiet.
• Опенспейс оказался тихим. = The open-plan office turned out to be quiet.

The second version suggests that this result may have been surprising or different from what people expected. That fits perfectly with вопреки ожиданиям.

So оказался adds the idea of:

• discovery
• result
• surprise
• contrast with expectation

The infinitive is оказаться.

In this sentence, оказался is:

• past tense
• masculine singular
• perfective

Why masculine singular? Because it agrees with опенспейс, which is a masculine singular noun.

So:

• он оказался
• опенспейс оказался

If the subject were feminine, you would get оказалась. If plural, оказались.

Because after оказаться, a full adjective used as a predicate is normally put in the instrumental case.

So:

• тихий = nominative
• тихим = instrumental singular

That is why Russian says:

• опенспейс оказался тихим

This is a very common pattern:

• Он оказался правым.
• Комната оказалась пустой.
• План оказался удачным.

With оказаться, the instrumental often marks the state or quality that something turned out to have.

A short adjective can sometimes be used instead in some sentences, but with тихий the full adjective in the instrumental is the normal, straightforward choice here.

They both agree with the subject опенспейс, which is masculine singular.

So you get:

• оказался — masculine singular past tense
• тихим — instrumental singular masculine

Even though тихим is not nominative, it still matches the subject in gender and number.

So the agreement is:

• subject: опенспейс — masculine singular
• verb: оказался — masculine singular
• predicate adjective: тихим — instrumental singular masculine

The comma marks a pause after the fronted phrase Вопреки ожиданиям and helps emphasize the contrast.

That opening phrase functions like an adverbial comment on the whole sentence:

• Contrary to expectations, ...

In practice, Russian writers often use a comma here to separate that opening circumstance from the main statement. It gives the sentence a clearer rhythm and makes the contrast stand out more strongly.

So the comma is there mainly for:

• pause
• readability
• emphasis

Yes. Russian word order is flexible, and changing it changes emphasis more than basic meaning.

For example:

• Вопреки ожиданиям, опенспейс оказался тихим.
• Опенспейс оказался тихим вопреки ожиданиям.
• Опенспейс, вопреки ожиданиям, оказался тихим.

All of these can work, but they focus attention differently.

The original sentence puts вопреки ожиданиям first, which highlights the contrast immediately. That is probably the most natural choice if the speaker wants to stress that the result was surprising.

Yes, it is very natural.

Why it sounds idiomatic:

• вопреки ожиданиям is a common set phrase
• оказался is exactly the kind of verb Russian uses for turned out to be
• тихим in the instrumental is the normal pattern after оказаться
• опенспейс is a common modern borrowed word in business or office contexts

So the sentence sounds like normal contemporary Russian, especially in workplace or conversational contexts.