Accounts Receivable (Tables)

3 Months Ended

Mar. 31, 2013

Accounts Receivable [Abstract]

Summary of accounts receivable

	2013			2012
Billed:
SG Block sales	$	278,709		$	207,390
Engineering services		250,777			216,535
Project management		94,054			34,900
Total gross receivables		623,540			458,825
Less: allowance for doubtful accounts		(174,430	)		(174,430	)
Total net receivables	$	449,110		$	284,395