This is the 311th most frequent Swedish word.
byggt
"Byggt" means "built" in English.
Here, 'byggt' is used as the past participle of 'bygga'. It appears in combination with the verb 'har' to form the perfect tense.
Jag har byggt ett hus.
I have built a house.
In this sentence, 'byggt' is the past participle used in a passive construction to describe the state or construction material of the house.
Huset är byggt av sten.
The house is built of stone.
Here, 'byggt' is again the past participle, now used in an infinitive phrase to describe the action that took place earlier.