GlazingType | U - Value (W/m2K) | Double Glazing, air filled, 6mm gap | 3.1 | Double Glazing, air filled, 12mm gap | 2.8 | Single Glazing | 4.8 |
Double thickness brick wall without air gap Wall Component | Conductivity (W/mK) | Thickness(m) | Conductance(W/m2K) | Resistance (m2K/W) | Outside Air Layer | | | | 0.04 | External render | 0.50 | 0.018 | 27.78 | 0.04 | External brick | 0.77 | 0.102 | 7.55 | 0.13 | Internal brick | 0.56 | 0.102 | 5.49 | 0.18 | Dense Plaster | 0.57 | 0.013 | 43.85 | 0.02 | Inside Air Layer | - | - | - | 0.13 | Totals | | 0.19 | | 0.54 | Overall U-Value | | | | 1.85 |
Double thickness brick wall without air gap but with wooden cladding Wall Component | Conductivity (W/mK) | Thickness(m) | Conductance (W/m2K) | Resistance (m2K/W) | Resistance (m2K/W) | Outside Air Layer | | | | | 0.04 | Wooden Cladding and battens | 0.13 | 0.05 | 2.6 | - | 0.38 | Sheltered surface resistance | | | | 0.13 | - | External brick | 0.77 | 0.102 | 7.55 | 0.13 | 0.13 | Internal brick | 0.56 | 0.102 | 5.49 | 0.18 | 0.18 | Dense Plaster | 0.57 | 0.013 | 43.85 | 0.02 | 0.02 | Inside Air Layer | - | - | - | 0.13 | 0.13 | Totals | | 0.19 | | 0.59 | 0.88 | Net Resistance | | | | 0.61 | | Net U Value (W/m2K) | | | | 1.64 | |
Note: BRE guidance is to disregard the rain cladding and use a sheltered surface resistance value. However, the calculation should allow for timber battens. If the battens occupy 10% of the surface area then the effective resistance is 1/((0.9/0.59)+(0.1/0.88)) = 1/(1.64 + 0.11) = 0.61 m2K/W
Double thickness brick wall without air gap but with wooden cladding and insulation between battens.Wall Component | Conductivity (W/mK) | Thickness(m) | Conductance (W/m2K) | Resistance m2K/W | Resistance m2K/W | Outside Air Layer | | | | 0.04 | 0.04 | Wooden Cladding and Battens | 0.13 | 0.05 | 2.6 | - | 0.38 | Wooden Cladding | 0.13 | 0.025 | 5.2 | 0.19 | - | Insulation between battens | 0.03 | 0.025 | 1.2 | 0.83 | - | External brick | 0.77 | 0.102 | 7.55 | 0.13 | 0.13 | Internal brick | 0.56 | 0.102 | 5.49 | 0.18 | 0.18 | Dense Plaster | 0.57 | 0.013 | 43.85 | 0.02 | 0.02 | Inside Air Layer | - | - | - | 0.13 | 0.13 | Totals | | 0.19 | | 1.52 | 0.88 | Net Resistance | | | | 1.4 |
| Net U Value (W/m2K) | | | | 0.71 |
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Double thickness brick wall with air gap and renderWall Component | Conductivity (W/mK) | Thickness(m) | Conductance (W/m2K) | Resistance (m2K/W) | Outside Air Layer | - | - | - | 0.04 | External render | 0.50 | 0.018 | 27.78 | 0.04 | External brick | 0.77 | 0.102 | 7.55 | 0.13 | Air Cavity | - | 0.1 | - | 0.18 | Internal brick | 0.56 | 0.102 | 5.49 | 0.18 | Dense Plaster | 0.57 | 0.013 | 43.85 | 0.02 | Inside Air Layer | - | - | - | 0.13 | Totals | | 0.19 | | 0.72 | Overall U-Value | | | | 1.39 |
Double thickness brick wall with insulated cavity and renderWall Component | Conductivity (W/mK) | Thickness(m) | Conductance (W/m2K) | Resistance (m2K/W) | Outside Air Layer | - | - | - | 0.04 | External render | 0.50 | 0.018 | 27.78 | 0.04 | External brick | 0.77 | 0.102 | 7.55 | 0.13 | Insulated Cavity | 0.039 | 0.089 | 0.44 | 2.27 | Internal brick | 0.56 | 0.102 | 5.49 | 0.18 | Dense Plaster | 0.57 | 0.013 | 43.85 | 0.02 | Inside Air Layer | - | - | - | 0.13 | Totals | | 0.19 | | 2.81 | Overall U-Value | | | | 0.36 |
Double thickness brick wall with air gapWall Component | Conductivity (W/mK) | Thickness(m) | Conductance (W/m2K) | Resistance (m2K/W) | Outside Air Layer | - | - | - | 0.04 | External brick | 0.77 | 0.102 | 7.55 | 0.13 | Air Cavity | - | 0.1 | - | 0.18 | Internal brick | 0.56 | 0.102 | 5.49 | 0.18 | Dense Plaster | 0.57 | 0.013 | 43.85 | 0.02 | Inside Air Layer | - | - | - | 0.13 | Totals | | 0.19 | | 0.68 | Overall U-Value | | | | 1.47 |
Double thickness brick wall with insulated cavityWall Component | Conductivity (W/mK) | Thickness(m) | Conductance (W/m2K) | Resistance (m2K/W) | Outside Air Layer | - | - | - | 0.04 | External render | 0.50 | 0.018 | 27.78 | 0.04 | External brick | 0.77 | 0.102 | 7.55 | 0.13 | Insulated Cavity | 0.039 | 0.1 | 0.39 | 2.56 | Internal brick | 0.56 | 0.102 | 5.49 | 0.18 | Dense Plaster | 0.57 | 0.013 | 43.85 | 0.02 | Inside Air Layer | - | - | - | 0.13 | Totals | | 0.19 | | 3.1 | Overall U-Value | | | | 0.32 |
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