Block Selection - suggestions

[Capable Noob]

Bungalow extension block requirement.  The drawing states "Blockwork to be 100mm medium density (frost resistant below DPC).  To provide a minimum mass per unit area (laid weight) of 120kg/m2.  A mean compressive strength 3.5n/m2 and a thermal conductivity of 0.45w/mk."

 

It will be a rendered finish.

 

I was about to place the order for the blocks and spoke to the supplier's helpline to confirm suitability and it turns out that the ones I was going to order aren't suitable for 150mm above or below the ground level - so I'd need 2 courses of engineering bricks either side of the ground level.

 

I'd rather use blocks all the way really - can anyone recommend a suitable block which I can use throughout?  

 

Many thanks

[Temp]

I've read that blocks below DPC should be 7N/m^2 or greater.  Top left page 2. Or is this out of date?

 

Also quotes a BSI standard they should meet.

 

https://www.cba-blocks.org.uk/wp-content/uploads/2018/03/CBA-2pp-Wall-below-DPC-rnd3.pdf

 

 

 

[Temp]

NHBC..

 

https://nhbc-standards.co.uk/5-substructure-ground-floors-drainage-and-basements/5-1-substructure-and-ground-bearing-floors/5-1-13-durability/

Quote

 

Blockwork

Concrete blocks for use below the DPC should meet BS EN 771 and one of the following

 

Minimum density of 1500kg/m3

Minimum compressive strength of 7.3N/mm2

assessed in accordance with Technical Requirement R3.

 

 

 

 

 

[Temp]

https://www.thomasarmstrongconcreteblocks.co.uk/concrete-block-foundation.html