Could someone summarize what it is and what the impacts could be?

It could impact your home equity and financial security.For a safer and more specialized alternative, consider a Fix & Flip loan. 

Each value add step in lumber is a doubling impact.  

How have you seen local ordinances or restrictions impact these projects?

That's significant and really impacts margins.

@Venecia BaezRecommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a Class A property in Class D area, what quality of tenant will you get?

@Adam OrtizRecommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

We have definitely seen “global” money impact SF, and while it’s less today, it still has an impact and will continue in the future.

@Kendric BufordRecommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

Quote from @Levi Perl: The purpose of background screening is to determine a level of risk, and then you decide if you can mitigate that risk.How does a DUI conviction from three years ago impact the tenant's ability to pay rent or maintain the property?