This is the 782nd most frequent Swedish word.
byggas
"Byggas" means "to be built" in English.
Here, 'byggas' is used in the future passive form indicating that the subject (the house) will undergo the action of construction.
Huset ska byggas nästa år.
The house will be built next year.
Here, 'byggas' is in the necessity modal passive form, emphasizing the requirement for the bridge's construction method.
Bron måste byggas stark för att motstå floden.
The bridge must be built strong to withstand the river.
In this example, 'byggas' suggests the creation or foundation of something abstract, in this case, the society.