As a type of architectural construction toy, this category is borderline, as the parts produced are often not re-useable. However, since one can generally always create more parts (since additional raw materials were usually available) and as most kits permitted enough variety to allow a range of different buildings to be created, they do qualify!
A good example of this type of set is Brick Craft. This set from the 1950's(?) contains a rubber mould for bricks and a powder which is mixed with water (using implements provided) and poured into the mould to set. This set also includes paper for roofing, paints and brush, and cardboard windows and doors.
Other sets in this catagory include contemporary kits which provide moulds for Plasticine or modelling clay and older sets from the 1930's to 1960's with a variety of mould types to be used with a plaster or concrete mix. These sets generally produce individual building blocks of various shapes, but an alternative approach is to mould whole wall sections.
The british Linka sets from the 1970's provided shallow flexible moulds which produced wall sections, with brick or stone textures, either plain or with various doors or windows. Roof parts were produced in the same way, with various tile patterns. The pieces produced have castellated interlockable sides. Additional moulds produce spires, tower tops and other specialist parts. The sets included some plastic parts such as gutters and drain pipes, and glue to fix everything together.