On 19 Mar, 23:34, jim wrote:
Metric sized building blocks (commonly 440 x 100 x 215mm) have been
around since metric sizes arrived in the 70s.

What is the application for 'modular sizes' (eg 390 x 100 x 190 - even
390 x 90 x 190)?

eg

http://www.plasmor.co.uk/html/produc...selector/concr...

Is a new standard being introduced? *Most block manufacturers websites
show this size in addition to the metric ones.

Also, especially, why 90mm? *Anything less than 100mm in a wall leaf
is usually frowned on.

I inadvertently bought some grr...grrr...

Anyone know?

TIA for any info

Its to create spacing of 400mm and 200mm, supposedly reduces cutting,
presumably when its all blocks and no bricks.
Also, as others pointed out, reduced weight.
I bought some standard sized blocks, and noticed they were all about
95mm. Was quite obvious when laying in with some bricks, 102.5mm.
Simon.