Betta Bilda (often mistaken for 'Better Builder') was a cheaper version of Lego with little white bricks and small squares of plastic that you clicked together to make "slate" roofs. Although Lego took over the universe, I personally preferred Betta Builder as the small bricks enabled you to make more detailed models.
I remember seeing a model in Woolworths of Big Ben that was about 8 foot tall. Although I never managed anything needing so many bricks I did build a cathedral.
Although suitable for children of all ages, Betta Bilda sets were notoriously challenging and instructions recommended that you got used to how the bricks worked together to provide the best 'structural support' before endeavouring to set out to construct a bigger object.
Betta Bilda was part of the Airfix range. House and vehicles, like lorries were the most popular sets.