Accounts Receivable

9 Months Ended

Sep. 30, 2019

4.	Accounts Receivable

At September 30, 2019 and December 31, 2018, the Company’s accounts receivable consisted of the following:

	September 30, 2019			December 31, 2018
Billed:
Block sales	$	—		$	14,723
Construction services		1,306,567			1,619,498
Engineering services		333,230			400,877
Retainage receivable		544,911			543,417
Other receivable		37,526			7,706
Total gross receivables		2,222,234			2,586,221
Less: allowance for doubtful accounts ⁽¹⁾		(785,895	)		(839,895	)
Total net receivables	$	1,436,339		$	1,746,326
⁽¹⁾ The allowance for doubtful accounts is primarily due to unpaid billings on a contract that is currently in dispute.

Receivables are evaluated for collectability and allowances for potential losses are established or maintained on applicable receivables. The allowance for doubtful accounts was $785,895 as of September 30, 2019. There was no provision for doubtful accounts, $54,000 collected for doubtful accounts and no write offs for the nine months ended September 30, 2019. The provision for doubtful accounts was $810,580 and write offs were $4,920 for the year ended December 31, 2018.