I og med at fasaden er gammel, kreves rehabilitering.

It means something like because, since, given that, or seeing that.

In this sentence, it introduces the reason for the main statement:

• I og med at fasaden er gammel = Because/Since the façade is old

Compared with fordi, i og med at often sounds a bit more formal, explanatory, or administrative.

Because i og med at is the full conjunction used before a clause.

It is best learned as one fixed expression:

• i og med at + clause

So here:

• i og med at fasaden er gammel

The word at links the expression to the full clause fasaden er gammel.

Because fasaden is the definite singular form: the façade.

• en fasade = a façade
• fasaden = the façade

Norwegian often uses the definite form when talking about a specific thing already known in the situation. Here it is not just any façade, but the particular façade being discussed.

Because gammel is a predicate adjective, not an adjective placed directly before the noun.

Compare:

• fasaden er gammel = the façade is old
• den gamle fasaden = the old façade

After er, the adjective agrees with gender and number, but not with definiteness in the same way as when it stands before the noun.

Since fasade is a common-gender singular noun, the predicate form is:

• gammel

Because Norwegian main clauses follow the V2 rule: the finite verb must come in the second position.

The first position here is already taken by the whole opening clause:

• I og med at fasaden er gammel

So in the main clause, the finite verb must come next:

• kreves

After that comes the subject:

• rehabilitering

So the structure is basically:

• [Reason clause], kreves rehabilitering

Without the opening clause, a more basic order would be:

• Rehabilitering kreves

Kreves is the present passive form of kreve.

• krever = requires / demand(s)
• kreves = is required

So:

• rehabilitering kreves = rehabilitation is required

The -s passive is very common in formal, official, technical, and written Norwegian.

Yes, in this sentence rehabilitering is best understood as the grammatical subject of the passive clause.

A simple way to see it is:

• Rehabilitering kreves = Rehabilitation is required

When the reason clause is placed first, Norwegian changes the word order because of V2:

• I og med at fasaden er gammel, kreves rehabilitering

So rehabilitering is still the thing that is required, even though it comes after the verb.

Yes, that is also possible.

• Det kreves rehabilitering = Rehabilitation is required

That version uses det as a kind of formal or empty subject, which is common in Norwegian.

The sentence you were given is more compact and slightly more written in style:

• I og med at fasaden er gammel, kreves rehabilitering

Both patterns are useful to recognize.

In a building context, rehabilitering usually means fairly substantial restoration, repair, or renewal work to bring something back into proper condition.

It is often more technical or serious than:

• oppussing = cosmetic renovation / redecorating / sprucing up

It can overlap with:

• renovering = renovation

But rehabilitering often suggests that the building element is worn, damaged, outdated, or in need of significant corrective work.

Yes.

You could say:

• Fordi fasaden er gammel, kreves rehabilitering.

That is grammatical and natural.

The difference is mainly tone:

• fordi = more neutral, everyday because
• i og med at = slightly more formal, explanatory, or bureaucratic

So both work, but i og med at may sound more like written assessment or official language.

Because the sentence begins with a subordinate clause, and Norwegian normally separates that from the main clause with a comma.

Here:

• I og med at fasaden er gammel = subordinate clause
• kreves rehabilitering = main clause

So the comma marks the boundary between them.

Yes, fairly formal.

Several features make it sound formal or written:

• i og med at
• the passive form kreves
• the noun rehabilitering

In everyday speech, people might choose a more direct version, for example:

• Siden fasaden er gammel, må den rehabiliteres.
• Fasaden er gammel, så den må rehabiliteres.

Those versions sound more straightforward and conversational.