Composite Rate Build Up – Internal Walls Superstructure
The Elemental Estimate layout and grouping of items will be used in this example. When building up composite rates for Approximate Quantities, you have to follow some basic principles. We are going to illustrate a composite rate buildup for Internal Walls:
Superstructure 115mm internal one brickwall 2900mm high, 150mm wide reinforcement every third course, including one coat cement plaster on smooth plastered walls both sides, one coat plaster primer and two coats Plascon Wall paint on both sides.
Step 1
First, you have to determine the Group unit of measurement. When you are measuring the internal walls (superstructure) in Elemental or Approximate Quantities estimating, the group unit of measurement is the square metre (m2).
Step 2
The second step is listing all associated Bill items that can be mapped to Internal Walls by area. These are:
 115mm one brickwall – (m2) Rate – R131
 75mm wide brick reinforcement – (m) Rate – R2.50
 One coat cement plaster – (m2) Rate – R30
 Painting (undercoat and overcoat) – (m2) Rate – R30
Step 3
Since your Group unit is the square metre (m2), you should convert the Bill item rates to Cost per Square Metre.
Rate Build Up
GROUP – INTERNAL DIVISIONS (SUPERSTRUCTURE) 
Rate – Cost Per Square Metre (m2) Rands  
Approximate  Elemental  
1m2 of One brickwalls:  
1m2 = R131  131  131 
1m2 of Brick reinforcement:  
1 course = 86mm including mortar joint
3 courses = 86 x 3 = 258mm 

1000mm Wall height has :
1000/258 = 3.88 Layers ,which is approximately 3.00 Layers. Therefore 1m2 of brickwall has 3 Layers of brickforce. 3 Layers x 1m = 3m of reinforcement. 

3m x R2.50 = R7.50  7.50  7.50 
138.50  
1m2 Cement plaster:  
1000 x 1000 x 2 sides  
1 x 1 x 2 = 2.00m2  
2.00m2 x R30 = R60  60  30 
1m2 Painting on plaster:  
1000 x 1000 x 2 sides  
1 x 1 x 2 = 2.00m2  
2.00m2 x R30 = R60  60  30 
60  
Composite Rate – INTERNAL DIVISIONS  258.50 
The composite rate for INTERNAL DIVISIONS (Superstructure Half Brickwalls) is R258.50 per square metre.
Elemental Layout and Grouping
Items which go into the element INTERNAL DIVISIONS and components Brick & Block Walls are stated in the description:

Unit  Quantity  Unit Rate  Cost/m2  Subtotal  Cost  
INTERNAL DIVISIONS


Brick and Block Walls:


115mm Half brickwall in superstructure (No openings), including 75mm reinforcement, and sundries.  M2  138.50  
Subtotal INTERNAL DIVISIONS 
Items which go into the element INTERNAL WALL FINISHES and component Finishes are stated in the description:
Unit  Quantity  Unit Rate  Cost/m2  Subtotal  Cost  
INTERNAL WALL FINISHES  
Finishes:  
One coat cement plaster on smooth plastered walls , PLUS one coat plaster primer and two coats Plascon Wall paint on external side.  M2  60  
Subtotal INTERNAL FINISHES 