2. Definitions & Terminology
- Eaves are BASIX calculations

3. What is BASIX
What is BASIX ? BASIX is the Building Sustainability Index. It is a web-based planning tool that is designed to assess Water, Thermal Comfort and Energy performance of a new home, extension or swimming pool (over Litres).  
Who needs a BASIX Certificate? A BASIX Certificate is required on all new single dwellings, dual occupancy, villas, townhouses and multi-units in NSW. A certificate is also required for alterations and additions over $50 000  and swimming pools at or over Litres

4. Types of Eaves Boxed Eaves
Eaves Trimmers also called Soffit Bearers

5. AS 1684 Allowable Methods
Soffit Bearers Minimum Sizes

6. Types of Eaves Open Eaves

7. Types of Eaves Open Slat Eaves

8. Types of Eaves Raked Eaves

9. Types of Eaves Flush Eaves

10. Flush Eaves Saves Cost Problems – IF Gutter Fails Scaffold Material
Labour
Problems – IF Gutter Fails
Water Runs Down Walls
Pools Formed at Footings
Causing Erosion, Swelling

11. Eaves Width Eaves on plans are usually measured from external walls
Rafter 90 x 45
Ridge 125 x 19

12. Overhang Plan usually from external wall

13. Always Confirm
In This case 740mm from internal wall

15. Drop Off Rafter 90 x 45 Pitch 25⁰
Distance From Top Plate to Bottom of Overhang

16. Calculating Drop Off Rafter 90 x 45 Pitch 25⁰
STEP 1 Calculate the RISE of Hatched Triangle

17. Calculating Drop Off Rafter 90 x 45 Pitch 25⁰
STEP 1 Calculate the RISE of Hatched Triangle
450mm x Tan 25⁰ = 210mm

18. Calculating Drop Off Rafter 90 x 45 Pitch 25⁰
STEP 1 Calculate the RISE of Hatched Triangle
450mm x Tan 25⁰ = 210mm
STEP 2 Add Birdsmouth =

19. Calculating Drop Off Rafter 90 x 45 Pitch 25⁰
STEP 1 Calculate the RISE of Hatched Triangle
450mm x Tan 25⁰ = 210mm
STEP 2 Add Birdsmouth
= 243

20. Remember Overhang Usually Specified From External Wall but Calculated For Back of Birdsmouth
Rafter 90 x 45
Pitch 25⁰
What is the Drop Off
Cavity = 40m
Brick = 110m
What is the Drop Off

21. Drop Off
Rafter 90 x 45
Pitch 25⁰

22. Drop Off Rafter 90 x 45 Pitch 25⁰
Remember to allow for min 12mm Clearance

23. Its Possible to have a Varying Drop Off
Rafter 90 x 45
Pitch 25⁰

24. Hazards Fall from Heights Contact with Live Electrical Wires
Materials, Tools falling From Heights
Scaffold Collapse or Toppling over
Dust
Complete Safe Work Method Statement

26. Cutting FC Sheeting Fibro Cutters Score & Snap Knife
Grinder with Diamond Blade (Dust Mask Required)

27. Estimating Step 1- Calculate Number of Soffit Bearers
12500 / 600 = = = 22 x2= 44
44 x 0.6 x 5% = 44 x 0.63
Fixing Plate 12.5

29. Estimating Step 2- Calculate Fascia
Length + Verge O/H = x = 13.7 x 2

31. Estimating Step 3- Calculate Barge Board
Barge Run = Half Span + Eaves Width + Fascia + Gutter =

33. Estimating Step 4- Soffit Lining Soffit = 2 x Length + 4 x Barge
= 2 x x 4804
= x 1.05(5% Waste) = / 2.4(Sheet Length) = = 20 Sheets

35. Estimating Step 5- Joining Mould 20 Sheets
21 Joins x 0.6 = 12.6 x 1.05 (5% Waste) = 13.23/2.4= 5.5 = 6 Lengths

37. Estimating
Step 6- Quad
2 x Building Length + 4 x Verge length (Rafter Centreline)
2 x x 3806 = x 1.05 (5% Waste)=