Building with Earth: Design and Technology of a Sustainable Architecture

197 Appendices

Measures

In this book, all measures as regards lengths
and areas as well as physical values are based on
the metric system. The Anglo-Saxon equivalent
of the U-value (describing thermal conductivity in
Central Europe) is the R-value, which has been
added in brackets. In this context, it must be
noted that the R-values are based on the metric
system.
To enable readers to convert values into the
imperial system that is most commonly used
in North America we have listed the most impor-
tant conversion factors as follows:

Lengths and areas

1 mm = 0.03937 inches
1 cm = 0.3937 inches
1 m = 39.37 inches

1 m^2 = 10.764 square feet
1 ha = 2.471 acres

1 inch = 2.54 cm
1 foot = 30.48 cm

1 square foot = 0.093 m^2
1 acre = 0.4047 ha

Physical values

Temperature

Centigrade (Celsius) – Fahrenheit

Multiply by 9/5 and add 32

°C °F

–10 14

032

10 5 0

20 68

30 86

R- and U-values

All R- and U-values in this book have been stated

according to the metric system. For the conver-

sion of the metric system (USI, RSI) into the

respective imperial system (U, R), the use of fac-

tors is required:

R x 0.1761= RSI

RSI x 5.6783 = R

U-values are the reciprocals of the respective

R-values and vice versa.

USI (W/m^2 K) RSI (m^2 K/W) U (BTU/hr * sq. ft. * °F) R (hr * sq. ft. * °F/BTU)

0.1 10 0.018 56.78

0.15 6.667 0.026 37. 86

0.2 5 0.035 20.39

0.3 3.333 0.053 18. 93

0.5 2 0.080 11.36

1. 0 1 0 .176 5. 6 8