Learn Dutch: De nieuwe bebouwing is erg hoog. - The new buildings are very tall.

The word bebouwing is a collective noun in Dutch. It literally means 'the built environment' or 'development'. Even though we often translate it as the plural 'buildings' in English to sound natural, it remains a singular concept in Dutch and therefore takes the singular verb is.

What is the difference between using bebouwing and gebouwen here?

Gebouwen refers to individual, countable buildings (e.g., De nieuwe gebouwen zijn erg hoog). Bebouwing is a more abstract, collective term for the structures in an area as a whole. You will often see it in contexts like urban planning, geography, or real estate.

Why do we use hoog for 'tall' here instead of lang?

In Dutch, hoog is used for the vertical height of inanimate objects like buildings, walls, and mountains. The word lang is used for the height of people (e.g., Hij is erg lang) or for horizontal length, like a long street.

Since this lesson focuses on enerzijds ... anderzijds, how would I use this sentence as the second half of a contrast?

You could say: Enerzijds is de wijk erg groen, anderzijds is de nieuwe bebouwing erg hoog. (On the one hand the neighborhood is very green, on the other hand the new buildings are very tall). Remember that starting a clause with anderzijds triggers inversion, placing the verb is before the subject de nieuwe bebouwing.