Sunday, September 7, 2014

Navigating minimum square footage requirements for tiny houses WITHOUT a trailer — International Residential Code says it can be as little as 138 square feet

I think that a lot of tiny house enthusiasts may be misperceiving minimum area regulations as a building code issue, and wanted to address that here. Below are the applicable minimum area standards that I've found in the 2012 International Residential Code (IRC) for one and two family dwellings—and they're actually quite simple:
  • R304.1 Every dwelling unit shall have at least one habitable room that shall have not less than 120 square feet of gross floor area*** (this requirement has been removed in the 2015 IRC)
  • R304.2 Other habitable rooms shall have a floor area of not less than 70 square fee (except kitchens)
  • R304.3 Habitable rooms shall not be less than 7 feet in any horizontal dimension (except kitchens)
  • R304.4 Portions of a room with a sloping ceiling measuring less than 5 feet between floor and ceiling shall not be considered as contributing to the minimum required habitable area for that room.
  • R306.1 Requires that every dwelling have a water closet, lavatory, and bathtub or shower (which could be as small as 18 sf while still meeting spacing requirements in Section 307)
  • R306.2 Requires that every dwelling have a kitchen area with a sink
  • I've found no requirements that the sleeping area or kitchen has to be in a separate room.
This means that the legal limit for a tiny house throughout the U.S.—according to your state building code—could be as small as 138 square feet (120 sf habitable room at 7' wide + 18 sf bathroom)

Even if one maintains the layout of a more traditional house, it could be as small as 260 square feet (bedroom @ 70 sf. + kitchen @ 50 sf + bathroom @ 20 sf + living room @ 120 sf)

***UPDATE: The 120 sf room requirement has since been eliminated in the 2015 IRC, meaning a dwelling could now be IRC compliant in as small as 88 square feet ( 70 sf habitable room + 18 sf bathroom). 

More on that recent change here: http://www.tentcityurbanism.com/2014/10/movement-growing-toward-legalizing-tiny.html


Simple illustrative drawing of an 8'x20' tiny house that meets
the 2012 IRC minimum area requirements

But this doesn't mean you're off the hook yet. More stringent requirements come in through local municipal code and zoning ordinances. Residential zoning categories are determined by density, and each category can come with strings attached for minimum lot and building area.

So, the challenge is presented by municipal code rather than state building code, which is nice because it can be more approachable given the right circumstances.

Even if a city has a minimum limit of say 600 square feet for a low-density residential zone, it is still possible to get a variance. The problem here is the dominantly individualistic approach taken by the tiny house movement so far. It has been about individuals wanting to downsize their own home. And while that may be an important thing in and of itself, many cities process thousands of permits a year, and an individual wanting to build a 140 square foot house is not going to be high on their to-do list. Furthermore, gaining exceptions often takes some money up front, which can be quite a burden on an individual trying to simplify their life.

However you are much more likely to be listened to when you are speaking for say 30 people, and even the financial burden becomes less of an impact per unit. This re-orients the tiny house as less of a personal desire and more of a new way of providing very low-cost housing to address large-scale, visible problems, like the severe lack of affordable housing in the U.S.

Implementing a tiny house community like Opportunity Village was not straightforward, but it was doable, we just had to make it of interest to enough people. Realizing early pilot projects like this then sets precedent for adjusting municipal code to set physical parameters for this new type of land use. And in my opinion, this will be most easily done through defining multi-unit tiny house developments rather than allowing a single tiny house in any residential zone.

There are plenty of legal methods for developing tiny houses now, we just have to be creative and work together. This presents an opportunity to not only address the over-sized nature of modern housing, but to also rethink the social isolation that it has come to embody. Addressing our current housing predicament takes more than just downsizing—it also means re-engaging in community.


Follow-Up Post: "Movement Growing Toward Legalizing Tiny Houses"

29 comments:

  1. Good news. The 120sf requirement is eliminated from the 2015 IRC. Tiny just got smaller.
    http://sustainablebuildingcodes.blogspot.com/2014/10/tiny-houses-120-square-foot-requirement.html

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    1. Thanks for the update Tom, and awesome work you're doing!

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    2. Hi Tom,

      Can this be applied anywhere in the USA?

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  2. Your own responses are especially correct inside Berkeley since university process even now uses the actual silly lottery process which aids parents drive an automobile their children across town to visit to university as opposed to planning to normally the one in walking mileage of the own residence.canam steel building

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  3. Regarding the 2015 IRC ... Keep in mind that in NY State and elsewhere, the 2015 rules don't take effect until the charges are formally adopted by state or city officials. Until then, the 120-square-foot rule remains in force. ... Also, I'd quibble with the assertion that you can stick a kitchen in a 120 sq. ft. room and still comply with the 120 sq. ft. rule. A zealous inspector might tell you that the floor space taken up by kitchen appliances and counters doesn't count. Better to be safe, and make your room just a little larger (whether it's 120 sq. ft. or 70). Finally, remember that an enclosed closet doesn't count as habitable space either. Unless you want to live without one, you'll need to add that as well.

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    1. The City of Eugene, OR is currently willing to accept the changes coming in the 2015 IRC, such as the 120sf room requirement, even though it hasn't been formally adopted yet. They just don't want us cherry picking from different codes. But yeah, if you live in an area that has no political interest in accommodating tiny houses, they could easily make it a much more difficult process.

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  4. And here's a link to the NY State Division of Code Enforcement. As of July 4, 2015, the 2015 IRC changes have not been adopted in NY state: http://www.dos.ny.gov/dcea/CodeUpdate.html

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  6. If anyone knows of variances granted or areas near Los Angeles County, California where less than 800 square feet is allowed, please let me know. NoteFromSELF@hotmail.com Thanks.

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    1. I would like to know in Illinois as well as the County of McHenry in Illinois added an amendment making the square footage 8oo. Can this practice of adding amendements be challenged. If counties can do that then what is the purpose of the IRC code if a few county board members can trump the code creators. Who's in charge and who is running the zoo. We need to start suing counties under the 14th amendment which protects people to Life, Liberty, and PROPERTY. How can anyone make a 800 sq. foot home efficient when it has to be 800 sq. ft. That's a waste of heat, AC, and adds a higher electric bill to the mix.

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    2. I agree LimoLine. These people do it to protect property values in the area. If a bunch of people move in and start building tiny houses the cost of the overall property will go down and so will the revenue. These people are money hungry and power hungry. I would like to one day develop a tiny house neighborhood on large lots, but that means the average property value will not make the city a lot in property taxes. They rather cram over sized homes in on small lots to maximize property taxes.

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  7. Does anyone know of a way to petition a county ground sq foot requirement? If anyone has experience on what to do let me know. I saw an old article about court cases ruling in favor of the people, but they were from like the 40's.

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  8. why is it seeming so difficult to do such basic simple things anymore. The northern part of reno nv, i am wanting to start with a prefab small cabin. I would like to do a dug well and a compost bathroom. I cant seem to find exact info on whether i can do this or not. Unless i am misunderstanding the bits and pieces of info i read. I am gathering nothing can be done without the mother may i from hoa's, city, county, etc. why is it i cant just do what i can afford on my own land?

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  10. If I build a house, without a permit what is the maximum square footage I can make?

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  11. Here in Upstate NY almost nothing happens. Code enforcement is like organized crime.

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  12. wanted to share space saving of my tiny house 12x24. Gonna take some imagination. First think of the first dimensions. its longer than wide.
    OK... I built a 9x9 cube at one end of the tiny house..leaving 15 feet for living room/dining room table. So that leaves 9X12 feet for one luxury bathroom, one full appliance kitchen, laundry room with nice big closet, entertainment center and a nice big bed.
    ok.. the 9x9 CUBE (the cube is built on a platform-secret to making this work) leaves 3extra feet.. gonna put 2 of it on side for kitchen and the other 1ft on laundry room side.
    There is a 6x9 (took up full 9ft for bathroom) for bathroom. Shower 4x7 feet walk in rock waterfall shower with bath basin in shower area. Looks like big care. On the outside of that the potty is in the 2ft area between shower casing and exterior wall. Wash basin in bathroom as well. Bathroom is my dream bath. I had an pool company design rock 'cave" and waterfall.
    So that leaves 3ft of cube on each side (except one I stole it for dream bathroom)....remember the cube is built up. It can be modified as needed for walkway space (which I did)...
    One side is laundry and cabinets. The 3ft perch is wide enough to hold appliances. (so that 1ft area turns into 4ft when you add cube space). I did cut base of cube at beginning entrance of laundry room and move washer/dryer down toward exterior wall to make bigger entrance (since I had 1ft off cube to work with).. the other side is kitchen. a 9ft wall 3ft deep is plenty enough for appliances and gives room for large china hutch on other wall. I took some of that cube off at entrance as well just to widen abit, more inviting. The front of the cube has the entertainment center on it with shelves for nik naks. The large bottom drawer is a pull out bed. queen size. So that left 15x12 feet for living area, dining room table (if I want to put leafs in)Plus I have a wooden play tower (like out side) inside with a full swing for my grandson (he's two).. he loves swinging in the house.
    I left the big barn doors so they open outside to a large deck/pool for parties. I spent tons of time picking lighting. I have lots of long lights that look like bubbles from a distance. (exposed ceiling/rafters).. I took a small trampoline and had it welded... bought one of those hanging beds and put on it w/huge pillows (no one sleeps on bed when they stay LOL).. I got the cube design from Chinese apartment living. It was something I came across while googling. Tore up all other plans. Oh on one end (I have two lofts).. 1/2 of my loft drops down so I can stand up straight up there and my bed is on elevated part. My work desk is underneath.. pain to get to, once you sit down, not so bad. I have a "cat walk" from one loft to the other only about 1 and 1/2 wide.. gotta stoop a bit.. was going to put down middle for full effect but ate up too much space. Have fun w/your tiny house. I didn't buy one but I found tiny complete kitchens for $1500 and up Summit C60EL

    60 Inch Combination Kitchen with 5.1 cu. ft. CT67 Refrigerator-Freezer, 2 Electric Burners, Stainless Steel Countertop, Sink, Faucet and Storage Compartments.... have fun w/your house and don't rush into design. do a bit at a time so it will be something ppl want to check out. They tell me all the time how HUGE my place is. its all about storage and design. (I have storage that runs along my cat walk (it looks designer though, I know its storage).. I also used them pop down things I saw them use in tiny house nation. Now I can put my stuff in the section while in the loft and pull the lever and get it while in the bathroom.. sweet. I wish I had time to tell you the other cool things Ive done. Next project is a fountain wall that has comes across my floor like a little river with koi in it and a small bridge (between living area and play area)..(probably not gonna happen, but in a tiny house.. its all about dreams!!!!)

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  13. This is a post of 2014. But I still like it. I found this post really informative and interesting. Now a tiny houses are trending. Beltsville Roofing Contractor

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  14. I would like to know the zoning requirements in Nebraska Specifically around lincoln.

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  15. What is the maximum square footage I can build my tiny house in California without having to get a permit?

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  16. I watched a documentary over the weekend on Tiny Houses in the Portland, OR area. One of the participants said they got around the zoning codes by parking in a "back yard" and calling the homes "Studios" (for their work.)

    Just thought I'd toss that in and then asked my question: Are you saying that a family of 12-13 could live in a tiny house of 138 square feet (or less) or am I to assume that to apply to one or two persons? Also, are you saying that state law regarding IRC can be more stringent, not less? Thanks for any reply offered.

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  18. The Hope/Clark Fork zone extends along the shores of Lake Pend Oreille from the Pack River to the mouth of the Clark Fork River, the major conduits that sustain powerful Pend Oreille. Lake Pend Oreille is one of the West's biggest freshwater waterways with a few islands close to the Clark Fork estuary, including the islands off Hope and the Hope Peninsula, Warren, Cottage, Pearl, Eagle, and Memaloose. Lowest-acceptable

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  19. The specialty of city working, in the wake of being lost and rejected for over a large portion of a century for decentralized business strip improvement and rural sprawl is being revived in a few 'New Town' ventures trimming around the nation. http://www.mordocrosswords.com/2016/11/a-foot-on-ground-in-phoenix.html

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  21. Good work on this post! I really like the way you delivered your qualitative facts and how you made this fascinating and effortless to realize. Thank you!! latest

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  22. I too agree with your point like implementing a tiny house community like Opportunity Village was not straightforward, but it was doable, we just had to make it of interest to enough people. Realizing early pilot projects like this then sets precedent for adjusting municipal code to set physical parameters for this new type of land use. Very informative.
    dmv construction :)

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