Accounts Receivable (Details) - USD ($)		Dec. 31, 2018	Dec. 31, 2017
Summary of accounts receivable
Total gross receivables		$ 2,586,221	$ 3,040,110
Less: allowance for doubtful accounts	[1]	(839,895)	(34,235)
Total net receivables		1,746,326	3,005,875
Block sales [Member]
Summary of accounts receivable
Total gross receivables		14,723
Construction revenue [Member]
Summary of accounts receivable
Total gross receivables		1,619,498	2,470,526
Engineering services [Member]
Summary of accounts receivable
Total gross receivables		400,877	196,008
Retainage receivable [Member]
Summary of accounts receivable
Total gross receivables		543,417	373,576
Other receivable [Member]
Summary of accounts receivable
Total gross receivables		$ 7,706

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