Accounts Receivable (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Summary of accounts receivable
Total gross receivables	$ 1,887,080	$ 2,586,221
Less: allowance for doubtful accounts	(785,895)	(839,895)	[1]
Total net receivables	1,101,185	1,746,326
Block sales [Member]
Summary of accounts receivable
Total gross receivables		14,723
Construction service [Member]
Summary of accounts receivable
Total gross receivables	1,321,575	1,619,498
Engineering services [Member]
Summary of accounts receivable
Total gross receivables	14,594	400,877
Retainage receivable [Member]
Summary of accounts receivable
Total gross receivables	544,911	543,417
Other receivable [Member]
Summary of accounts receivable
Total gross receivables	$ 6,000	$ 7,706

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