Part 13.3 External glazing

(1) This Part applies to—

1. a Class 1 building; and
2. a Class 10a building with a conditioned space.

(2) Part 13.3 must be applied as directed in H6D2(1)(b).

(1) In climate zones 2 to 8, the ratio of the conductance (C_u) and solar heat gain (C_SHGC) of the glazing in each storey, including any mezzanine, must—

1. not exceed the allowances obtained from Table 13.3.2a; and
2. be calculated in accordance with the following formula:

   $\frac{\left[\left(A_1\times U_1\times B{C}_1\times O{C}_1\times R_{W1}\right)+\left(A_2\times U_2\times B{C}_2\times O{C}_2\times R_{W2}\right)+...\right]}{\left[\left(A_1\times SHG{C}_1\times E_{W1}\times R_{W1}\times B{S}_{W1}\times L_{W1}\times F_{W1}\times H_{W1}\right)+\left(A_2\times SHG{C}_2\times E_W{}_2\times R_{W2}\times B{S}_{W2}\times L_{W2}\times F_{W2}\times H_{W2}\right)+...\right]}$

(2) In the formula at (1)(b)—

1. $A_{1,2,etc}$

   = the area of each glazing element; and

2. $U_{1,2,etc}$

   = the Total System U-Value of each glazing element; and

3. $SHG{C}_{1,2,etc}$

   = the Total System SHGC for each glazing element, not exceeding 0.7; and

4. $E_{W1,W2,etc}$

   = the winter exposure factor for each glazing element obtained from Table 13.3.2b, 13.3.2c, 13.3.2d, 13.3.2e, 13.3.2f, 13.3.2g, 13.3.2h, 13.3.2i, 13.3.2j, 13.3.2k, 13.3.2l, 13.3.2m, 13.3.2n, 13.3.2o, 13.3.2p or 13.3.2q; and

5. $B{C}_{1,2}{}_{,etc}$

   = the bedroom conductance factor obtained from Table 13.3.2r; and

6. $O{C}_{1,2,etc}$

   = the orientation sector conductance factor obtained from Table 13.3.2s, 13.3.2t, 13.3.2u, 13.3.2v, 13.3.2w, 13.3.2x or 13.3.2y; and

7. $R_{W1,W2,etc}$

   = the room type factor in Table 13.3.2z, 13.3.2aa, 13.3.2ab, 13.3.2ac, 13.3.2ad, 13.3.2ae, 13.3.2af or 13.3.2ag; and

8. $B{S}_{W1,W2,etc}$

   = the bedroom solar heat gain factor in Table 13.3.2z, 13.3.2aa, 13.3.2ab, 13.3.2ac, 13.3.2ad, 13.3.2ae, 13.3.2af or 13.3.2ag; and

9. $L_{W1,W2,etc}$

   = the factor in Table 13.3.2z, 13.3.2aa, 13.3.2ab, 13.3.2ac, 13.3.2ad, 13.3.2ae, 13.3.2af or 13.3.2ag for each glazing element located on a floor level above the lowest floor level; and

10. $F_{W1,W2,etc}$

    = the frame factor in Table 13.3.2z, 13.3.2aa, 13.3.2ab, 13.3.2ac, 13.3.2ad, 13.3.2ae, 13.3.2af or 13.3.2ag for each glazing element; and

11. $H_{W1,W2,etc}$

    = the floor factor in Table 13.3.2z, 13.3.2aa, 13.3.2ab, 13.3.2ac, 13.3.2ad, 13.3.2ae, 13.3.2af or 13.3.2ag for each glazing element.

(3) For the purposes of this clause—

1. orientation sectors must be determined in accordance with Figure 13.3.2a; and
2. P/H must be determined in accordance with Figure 13.3.2b.

(1) In climate zones 1 to 7, the aggregate solar heat gain of the glazing in each storey of a building, including any mezzanine, must—

1. not exceed the allowance resulting from multiplying the floor area of each storey, measured within the enclosing walls, by the constant C_SHGC obtained from Table 13.3.3a; and
2. be calculated in accordance with the following formula:

(2) In the formula at (1)(b)—

1. $A_{1,2,etc}$

   = the area of each glazing element; and

2. $SHG{C}_{1,2,etc}$

   = the Total System SHGC for each glazing element not exceeding 0.7; and

3. $E_{S1,S2,etc}$

   = the summer exposure factor for each glazing element obtained from Table 13.3.3b, 13.3.3c, 13.3.3d, 13.3.3e, 13.3.3f, 13.3.3g, 13.3.3h, 13.3.3i, 13.3.3j, 13.3.3k, 13.3.3l, 13.3.3m, 13.3.3n, 13.3.3o, 13.3.3p or 13.3.3q; and

4. $R_{S1,S2,etc}$

   = the factor in Table 13.3.3r, 13.3.3s, 13.3.3t, 13.3.3u, 13.3.3v, 13.3.3w, 13.3.3x or 13.3.3y for each glazing element located in a bedroom or room which is not a conditioned space; and

5. $L_{S1,S2,etc}$

   = the factor in Table 13.3.3r, 13.3.3s, 13.3.3t, 13.3.3u, 13.3.3v, 13.3.3w, 13.3.3x or 13.3.3y for each glazing element located on a floor level above the lowest floor; and

6. $F_{S2,S2,etc}$

   = the frame factor in Table 13.3.3r, 13.3.3s, 13.3.3t, 13.3.3u, 13.3.3v, 13.3.3w, 13.3.3x or 13.3.3y for each glazing element; and

7. $H_{S1,S2,etc}$

   = the floor factor in Table 13.3.3r, 13.3.3s, 13.3.3t, 13.3.3u, 13.3.3v, 13.3.3w, 13.3.3x or 13.3.3y for each glazing element.

(3) For the purposes of this clause—

1. orientation sectors must be determined in accordance with Figure 13.3.2a; and
2. P/H must be measured in accordance with Figure 13.3.2b.

Where shading is required to comply with 13.3.2 or 13.3.3, it must—

1. be provided by an external permanent projection, such as a verandah, balcony, fixed canopy, eaves, shading hood or carport, which—
   1. extends horizontally on both sides of the glazing for a distance greater than or equal to the projection distance P in Figure 13.3.2b; or
   2. provide the equivalent shading to (i) with a reveal or the like; or
2. be provided by an external shading device, such as a shutter, blind, vertical or horizontal building screen with blades, battens or slats, which—
   1. is capable of restricting at least 80% of the summer solar radiation; and
   2. if adjustable, is readily operated either manually, mechanically or electronically by the building occupants.