Mark McLean is the co-founder of Callum Walker Energy Source based in Fife in Scotland. Callum Walker Energy source focus on advising on and installing high end energy efficient home improvement measures such as triple glazing, heat recovery systems and all things PassivHaus. Mark also has his own personal website: http://markmclean41.wordpress.com/ where he writes and vlogs about issues more personal to him, as well as industry issues too. On a regular basis he has written a series of excellent guest posts for DGB, which you can browse through below.
Guest Columnist: Mark McLeanDGB2016-10-24T20:23:25+01:00