Regulating FAR in Residential Districts

Currently, the amount of floor area in residential zoned lots is not directly regulated. Structures are however,limited to 50% lot coverage -- meaning that you cannot build a structure that covers more than 50% of a residential lot. Believe it or not, even Monster Homes are built within that 50% coverage limit. In addition current zoning controls include minimum yard setbacks, height setback, height envelope and parking requirements. Bill 110(2017)CD1 FD1 proposes to add an additional limit of 0.7 FAR or floor area ratio to limit the amount of floor area allowed on residential zoned lots. FAR is already used to regulate floor area in apartment and business districts.

Lot Size	Approx Max Floor Area (currently allowed)*	FAR 0.7 (proposed)	Difference
3,500 sq ft	7,000 sq ft	2,450 sq ft	-4,550 sq ft
5,000 sq ft	10,000 sq ft	3,500 sq ft	-6,500 sq ft
10,000 sq ft	20,000 sq ft	7,000 sq ft	-13,000 sq ft

*Based on 1.0 FAR (flat lot). Sloped lots have a higher height envelope, which can allow more than 2-stories and thus floor area that exceeds 1.0 FAR.

The current zoning code requires a minimum 10' front and 5' side/read setbacks. Bill 110(2019) CD1 FD1 proposes to increase side and rear setbacks for "large detached dwellings" that exceed 0.7 FAR, from 5' to 7' minimum and 2' additional for every 1,000 sq ft above 4,000 sq ft. 

Rather than setting a fixed floor area maximum for all homes, Bill 110 (2017)CD1 FD1 proposes to use FAR or floor area ratio to define what is considered a "large detached dwelling" and then during the 2-year interim period, imposes additional restrictions such as increased setbacks (mentioned above) and on-site parking requirements. Most notably, new homes larger than 4,000 sq ft would be required to provide 6 on-site parking stalls, plus maneuvering space so that all cars can enter the street front first. The Bill proposes that homes up to 3,000 sq ft to 4,000 sq ft would still only be required to provide 2 to 3 stalls.  

For dwelling sizes* (sq ft)	Required spaces required	Current
Up to 2,999	2	2
3,000 - 3,999	3	3
4,000 – 5,000	6 + maneuvering	4, no maneuvering req’d
5,001 – 6,000	8 + maneuvering	5, no maneuvering req’d
6,001 – 7,500	10 + maneuvering	6, no maneuvering req’d
7,501 and up	Add 2 for every add'l 1,000 sq ft + maneuvering	Add 1 for every add'l 1,000 sq ft, no maneuvering req’d

*including the area of lanais. 

FAR relates the allowable floor area to lot size, meaning that larger lots are allowed to have greater floor area. Flat lots have a 25' height limit, which typically restricts homes to 2-stories max. Based on 50% lot coverage, a 2-story home that maxed out lot coverage, would effectively have a maximum FAR = 1.0. In comparison, Bill 110 CD1 FD1 defines "large detached dwellings" as new homes larger than 0.7 FAR. Large dwellings would be required to provide additional setbacks, additional parking and onsite maneuvering space in some cases, and most importantly, within the moratorium period, they would be required to obtain Council approval before a permit could be issued.

One suggestion to focus regulations and discourage Monster Homes, is to tier FAR limits (i.e., use a reduced 0.5 FAR for lots larger than 15,000 sq ft) so that larger lots would be allowed even less maximum floor area than the above table. A previous post on AIA Honolulu's Housing Committee Blog estimated the median size of new single and two-family dwellings permitted between 2005 to 2017 at 2,300 sq ft. 

One concern voiced in existing testimony was that establishing FAR limits would mean that existing homes that exceed the proposed floor area limit, would then be considered nonconforming. DPP has not released estimates of how existing homes would be affected. However, it is important to note that Ord 17-59 relating to nonconforming structures (passed 11/2017), increased the threshold of work allowed from 50% to 90%. 

Interestingly, it is not clear if the current wording of Bill 110 (2017) CD1 FD1 applies parking and setback requirements to expansion of existing large homes. The text of the Bill states that it would apply to: 

1. "A new large detached dwelling; 
2. The conversion of an existing structure into a large detached dwelling; or
3. A new accessory dwelling unit located on the same lot as an existing large detached dwelling."

Seems that an existing home with legally established with building permits that already exceeded 0.7 FAR would not be subject to these conditions.