Accounts Receivable (Details) - USD ($)		Jun. 30, 2019	Dec. 31, 2018
Schedule of accounts receivable
Total gross receivables		$ 2,234,401	$ 2,586,221
Less: allowance for doubtful accounts	[1]	(785,895)	(839,895)
Total net receivables		1,448,506	1,746,326
Block sales [Member]
Schedule of accounts receivable
Total gross receivables			14,723
Construction services [Member]
Schedule of accounts receivable
Total gross receivables		1,373,493	1,619,498
Engineering services [Member]
Schedule of accounts receivable
Total gross receivables		307,991	400,877
Retainage receivable [Member]
Schedule of accounts receivable
Total gross receivables		544,911	543,417
Other receivable [Member]
Schedule of accounts receivable
Total gross receivables		$ 8,006	$ 7,706

[1] The allowance for doubtful accounts is primarily due to unpaid billings on a contract that is currently in dispute.