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Do you know where true south is?

by mel starrs on January 18, 2007

in Building Physics

Fascinating snippet regarding the orientation of buildings:

“McDonough pointed out that many architects and builders don’t know how to find true south. If a compass is used, the compass indicates south, which can differ from true south by more than 15 degrees. Remember, orienting a home is about orienting the home to sun exposure, not magnetic south.”

McDonough is of course Bill, co-author of Cradle to Cradle, and eco-architect extraordinaire stateside.

I did a little surfing to find out what the difference between true south and magnetic south is. The easier way to find out in the UK is to check your local OS map which has a note on it (regarding true north and magnetic north). From the OS Explorer Map 289 for Leeds:

At the centre of the N and S sheets true north is 0º28′ and 0º27′ west of grid north respectively. Magnetic north is estimated at 3º18′ and 3º15′ west of grid north respectively for Jul 2008. Annual change is approximately 10′ east.

Which explains why you should not use a magnetic compass to site your building. If you want to read more on true south (or true north), sundials seem to be the way to go…

::via Jetson Green