About 5 years ago, we saw HOAs start to impose a minimum length for leases.

Their restrictive policy hasn’t worked (yet).

Town homes can be a good starting place depending on the restrictions.

**Legality Varies**: The legality and accepted use of BOVs/BPOs can vary by state, with some states restricting or prohibiting their use[2][4].In summary, broker opinions of value can be a cost-effective and timely way to get a rough estimate of a commercial property's worth, but they have limitations in terms of accuracy and acceptability compared to a professional appraisal.

IMO you will further restrict your renter pool. 

The zoning board can impose fines. also need to adjust lease agreements to reflect tenants status. in the end, with how lenders reflect potential rental income v mtg (dscr) harder to qualify the loan. 

We want to understand how much loan do lendors provide for buying the land and do they have any restrictions for the loan like need to build in 1 or 2 years etc.

So there may be no actual restriction on TCO for residential, but because of the challenges of doing this for residential homeowners they may have internally decided to restrict it to commercial. 

However, locally some places in PA are allowing ADU, but have restrictions that if you build one for a parent or a child, that once they leave it can NOT be rented to a non-relative. 

Make sure you purchase something void of CC&R STR restrictions.