Segments and Disaggregated Revenue (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Segments and Disaggregated Revenue
Revenue	$ 8,604,598	$ 9,187,627
Cost of revenue	6,118,163	8,631,002
Operating expenses	2,067,543	1,718,082
Operating income (loss)	418,892	(1,161,457)
Other income (expense)	82,836	17,107
Income (loss) before income taxes	501,728	(1,144,350)
Net income attributable to non-controlling interest	1,218,905	889,527
Net loss attributable to common stockholders of SG Blocks, Inc.	(717,177)	(2,033,877)
Total assets	37,963,197		$ 34,924,018
Capital expenditures	922,865	862,090
Operating Segments [Member]
Segments and Disaggregated Revenue
Revenue	8,604,599	9,187,627
Cost of revenue	6,118,163	8,631,002
Operating expenses	2,067,543	1,718,082
Operating income (loss)	418,892	(1,161,457)
Other income (expense)	82,836	17,107
Income (loss) before income taxes	501,728	(1,144,350)
Net income attributable to non-controlling interest	1,218,905	889,527
Net loss attributable to common stockholders of SG Blocks, Inc.	(717,177)	(2,033,877)
Total assets	37,963,197	27,248,283
Depreciation and amortization	165,473	141,793
Capital expenditures	922,865	862,090
Operating Segments [Member] | Construction [Member]
Segments and Disaggregated Revenue
Revenue	1,718,770	3,231,664
Cost of revenue	1,720,714	4,103,310
Operating expenses	109,163	6,150
Operating income (loss)	(111,107)	(877,796)
Other income (expense)
Income (loss) before income taxes	(111,107)	(877,796)
Net income attributable to non-controlling interest
Net loss attributable to common stockholders of SG Blocks, Inc.	(111,107)	(877,796)
Total assets	10,464,450	14,050,007
Depreciation and amortization	143,435	56,909
Capital expenditures	24,100	477,882
Operating Segments [Member] | Medical [Member]
Segments and Disaggregated Revenue
Revenue	6,885,829	5,955,963
Cost of revenue	4,397,449	4,527,692
Operating expenses	18,973	159,254
Operating income (loss)	2,469,407	1,269,017
Other income (expense)
Income (loss) before income taxes	2,469,407	1,269,017
Net income attributable to non-controlling interest	1,218,905	889,527
Net loss attributable to common stockholders of SG Blocks, Inc.	1,250,502	379,491
Total assets	4,857,366	5,047,318
Depreciation and amortization	263,169	84,619
Capital expenditures		36,890
Operating Segments [Member] | Development [Member]
Segments and Disaggregated Revenue
Revenue
Cost of revenue
Operating expenses	281,988
Operating income (loss)	(281,988)
Other income (expense)	(40,000)
Income (loss) before income taxes	(321,988)
Net income attributable to non-controlling interest
Net loss attributable to common stockholders of SG Blocks, Inc.	(321,988)
Total assets	8,889,271	127,395
Depreciation and amortization	8,628
Capital expenditures	893,785
Operating Segments [Member] | Corporate and support [Member]
Segments and Disaggregated Revenue
Revenue
Cost of revenue
Operating expenses	1,657,419	1,552,678
Operating income (loss)	(1,657,419)	(1,552,678)
Other income (expense)	122,836	17,107
Income (loss) before income taxes	(1,534,583)	(1,535,571)
Net income attributable to non-controlling interest
Net loss attributable to common stockholders of SG Blocks, Inc.	(1,534,583)	(1,535,571)
Total assets	13,752,110	8,023,564
Depreciation and amortization		265
Capital expenditures	4,980	$ 347,318
Intersegment Eliminations [Member]
Segments and Disaggregated Revenue
Revenue
Intersegment Eliminations [Member] | Construction [Member]
Segments and Disaggregated Revenue
Revenue
Intersegment Eliminations [Member] | Medical [Member]
Segments and Disaggregated Revenue
Revenue	160,500
Intersegment Eliminations [Member] | Development [Member]
Segments and Disaggregated Revenue
Revenue
Intersegment Eliminations [Member] | Corporate and support [Member]
Segments and Disaggregated Revenue
Revenue	$ (160,500)