Envelope Typical Values (Metric)

Glazing U-Factor (W/m2-k)

Description Lower Upper

Single Glazing

- including frame
and sash

4.00 6
Standard Double Glazing -
including frame and sash
3.01 4.01

Performance Double Glazing
(low-e)

- including frame and sash

2.01 3

Triple Glazing

- including frame
and sash

1 2

Triple Glazing (argon filled cavity)

- including frame and sash

0.4 1

 

Glazing SHGC

Description Lower Upper
Clear Single Glazing 0.71 0.9
Clear Double Glazing 0.41 0.7
Reflective Coated Glazing 0.21 0.4
Glazing with Internal Blinds 0.1 0.2

 

Surface Reflectance

Description Lower Upper

Mirror Finish

- highly reflective

0.9 1

Light coloured walls

- reflective

0.6 0.9
Medium coloured walls 0.4 0.6

Dark coloured walls

- low
reflectivity

0.1 0.4

Black

- very low reflectivity

0 0.1

 

Leakage (m3/m2-h)

Description Lower Upper
Leaky building 10 and above
Normal practice 5 10
Best practice 1 5
Extremely tight building 0 1

 

 

Roof Thermal Resistance U-value (W/m2-k)

Description Lower Upper

Uninsulated and single skin roofs

1.21 5

Poorly insulated

(approx. 50mm/2in insulation)

0.61 1.2

Insulated

(approx. 100mm/4in insulation)

0.26 0.6

Well insulated

(approx. 150mm/6in insulation)

 0.1  0.25

 

Floor Thermal Resistance U-value (W/m2-k)

Description Lower Upper

Uninsulated 

4.01 5

Poorly insulated

(approx. 50mm/2in insulation)

1.41 4

Insulated

(approx. 100mm/4in insulation)

0.26 1.4

Well insulated

(approx. 150mm/6in insulation)

 0.1  0.25

 

Walls Thermal Resistance U-value (W/m2-k)

Description Lower Upper

Uninsulated 

1.1 5

Poorly insulated

(approx. 50mm/2in insulation)

0.49 1.2

Insulated

(approx. 100mm/4in insulation)

0.36 0.5

Well insulated

(approx. 150mm/6in insulation)

 0.1 0.35

 

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