Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Aug. 10, 2019
Document and Entity Information [Abstract]    
Entity Registrant Name SG BLOCKS, INC.  
Entity Central Index Key 0001023994  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Document Type 10-Q  
Document Period End Date Jun. 30, 2019  
Document Fiscal Period Focus Q2  
Document Fiscal Year Focus 2019  
Entity Filer Category Non-accelerated Filer  
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity Small Business true  
Entity Emerging Growth Company false  
Entity Ex Transition Period false  
Entity Common Stock, Shares Outstanding   6,007,791
Entity File Number 001-38037  
Entity Address, Address Line One 195 Montague Street,  
Entity Address, City or Town Brooklyn  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 11201  
Entity Tax Identification Number 954463937  
City Area Code (646)  
Local Phone Number 240-4235