Deal breakers
This page is only useful if it's right. If you find a mistake, tell me and I'll fix it.
This is the list of things that could sink this.
I'm building an ADU in Post Falls, but the bigger picture is housing affordability in Idaho. I'm keeping a list of all the objections, issues, questions, and pushback on the topic here, and I work through it. Some of these I've answered and can show you where. Some I'm still working on. Nine of them are still open, and those stay on the list until they're sorted out.
I aim to represent each issue in its strongest form. If I water it down to make it easier to knock over, that doesn't help anyone. If a deal breaker turns out to be real, I'd rather find out here than halfway into a build. I wrote about why this page exists in The arguments against more housing, including nine I can't answer.
If you've got one that isn't on this list, send it to me and I'll add it. This is only useful if the people who disagree with me help build it. Contact me here, or message the Facebook page, or leave it in the comments on any post. I'll add it whether or not I have an answer, and I'll credit you unless you'd rather I didn't.
If you think one of my answers is wrong, that's worth more to me than a new entry. Cleared means I think there's a good answer, but that might not be right. Read the post, then tell me what I'm missing. If you change my mind I'll say so on the page and put your name on it.
Cleared, and here's how
Cleared is my judgment. I'm providing links so you can check my work. If you read it and still disagree, say so and I'll either fix it or change the status of the issue.
Cleared Building expensive houses doesn't help people who can't afford expensive houses. It does, and there's data.
An economist named Evan Mast traced tens of thousands of moves and found that 100 new homes, even pricey ones, open up about 70 homes in lower-income neighborhoods and about 40 in the poorest ones, within a few years. Bigger new homes make longer chains, not shorter ones. This is the one I feel best about.
Read how
Cleared Housing is zero-sum. Somebody gets the house and the rest of us lose something. Nobody loses.
A vacancy chain isn't a fight over one house where one family wins and everyone else goes home empty. Every spot in the line moves up at once. That's the part I'd most want someone to take away from this whole site.
Read how
Cleared More housing just means more sprawl, and the taxpayer pays for the new roads and pipes. Not for an ADU.
The road is already there. So is the water, the sewer, and the school. An ADU reuses all of it. No new subdivision, and it costs the town less than building that infrastructure again somewhere new. Sprawl is a fair worry about a greenfield subdivision. It isn't one about a small second home in an existing backyard.
Read how
Cleared The new state law overrides your city code. Just build to the state law and ignore the city. I wish, but no.
Cities have until February 1, 2027 to update their codes. I asked Post Falls directly, and the planning manager told me by email that they're reviewing applications against the adopted city code today. I'm not a lawyer and I'm not going to tell you the city's rules are simply void. This is the answer I'd least like to give and it's still the right one.
Read how
Cleared Permit and connection fees price an ADU out before you pour anything. Not in Post Falls.
I read the city's fee schedule and thought I was looking at $13,000 in water and sewer connection fees. I was wrong. An ADU on a lot that already has a house shares the existing water and sewer, so no capitalization fee is owed. The city says $1,000 to $2,000 instead. It took two emails and three days to get that answer, which is its own problem.
Read how
One caveat: that's city sewer. On a county parcel with a septic system the numbers are different and I haven't finished that research.
Working on it
Working on it An ADU doesn't create a first-time buyer. It's a rental or an in-law suite for somebody who already owns. Half answered.
The ADU doesn't have to house the young couple. It moves the line. If my mother-in-law moves into the ADU I build, her three-bedroom house across town opens up, and maybe that's where my son and his girlfriend end up. What I can't claim yet is that it puts anyone on the ownership ladder specifically. Freeing up a house to rent and freeing up a house to buy aren't the same thing, and this one is about the second one.
Read how
That covers the chain. The ownership half is still open.
Working on it Free pre-approved plans already solved the plan problem. Read the fine print.
There are four free ADU plan sets for Kootenai County and they're genuinely useful. But one of the four says on its own sheets that footings and foundation "need to be completed by others," which makes it a design proposal rather than a permit-ready set. None of the four include a basement. And all four predate the new state law. Whether starting from one actually shortens permitting, I don't know yet. I'm finding out on my own build.
Read how
Working on it Short-term rentals take housing off the market. Encouraging ADUs as rentals makes it worse. You're right about conversions.
Turning an existing house into a nightly rental does remove a home somebody could live in, and the research generally supports that. What I'd argue is narrower: a newly built ADU adds a unit that didn't exist before, so it can't subtract from long-term supply the way a conversion does. I haven't found the study that tests that specific claim, so I'm not publishing the broad version.
No post yet.
Working on it ADUs raise what a property costs, so they make the pricing problem worse. Probably not, but I can't prove it.
The argument I've heard against it is that a house with an ADU isn't a comp for a house without one, and that most owners don't sell the unit off separately anyway. That sounds right to me and I don't have the sales data to back it up.
No post yet.
Working on it The state telling cities what to allow is the same central planning, just moved to Boise. A real argument.
The sponsor's answer is that there's nothing more local than a person deciding what to do with their own property, and that the state is protecting that rather than overriding it. I find that convincing, but it's an assertion, not evidence, and it's his rather than mine. If you think local control is the thing being protected here, you and I disagree about where the local part actually sits.
No post yet.
Working on it The infrastructure can't take it. The law already handles this.
The new statutes don't override capacity limits. An ADU gets denied for inadequate sewer or water on exactly the same terms a regular house would. Both the new ADU law and the new starter-home law carve out aquifer recharge zones on purpose. What I haven't done is check whether any specific Post Falls system is actually near its limit.
Part of it is here
Under reusing what is already there. No post of its own yet.
Working on it There is no housing crisis. Per square foot, housing is cheaper than it was in 1956. You're solving a problem that doesn't exist. His numbers are right. The conclusion is backwards.
An economist at Cato ran this and I think his math holds. Measured in hours worked, a square foot of house costs about 24% less than it did in 1956, and we have gained 532 square feet of living space per person since then. If that's true, the argument goes, nothing is broken and I'm building a solution to a problem we don't have.
The square foot is the wrong unit, and the average is the wrong buyer. Homes nearly doubled in size over that same stretch, so the price of a house went up hard even while the price of a square foot fell. A first-time buyer isn't shopping for square feet. He's shopping for a payment he can make, and he takes the smallest house that clears it. That's the bottom rung. The bottom rung is the one that got cut. The small home his own math describes, around 874 square feet, is illegal to build on most lots in America today. Minimum lot sizes, minimum dwelling sizes, setbacks. The cheap thing he's pricing isn't for sale because nobody is allowed to build it.
So his study actually makes my case. If the affordable thing has always been the small dwelling, the fix is to make small dwellings legal to build again. That's an ADU.
No post yet. This deserves its own.
Working on it Just move somewhere cheaper. Cheap houses exist, just not where the jobs are.
They're also not where your parents are, or your church, or the school your kids go to. Telling people to leave is a real option and it's the one my sons are actually considering. That's the outcome I'm trying to prevent, not a solution.
Read how
No post aimed straight at it yet.
Still open
Open If you make housing cheaper here, everyone will just move here and it won't be cheaper anymore. I don't have a good answer yet.
This is the one I hear most and the one I'm least ready for. Somebody put it to the mayor of Post Falls directly, with the Californians-arriving version of it. I have a starting point in how Tokyo held prices down while its population grew, but I haven't done the work, and I'm not going to hand you a confident answer I haven't earned. This is at the top of my list.
No answer yet.
Open Renting is fine. Not everybody needs to own, and right now renting is cheaper here than buying anyway. I have to settle this one before I say much else.
The monthly math might well be on your side today. At these rates the payment on a bought house beats the rent on the same house plenty of the time, and I haven't run those numbers for Kootenai County. What I'd argue is that renting and owning aren't the same deal over thirty years. One builds equity. The other doesn't. But that's a belief I hold, not a number I've checked. If renting really does win here at today's rates, then telling young families to buy is bad advice, and I should stop giving it until I can show the work.
No answer yet.
Open It's an education problem. There is affordable inventory and buyers don't know about it. Haven't tested it.
The president of Boise Regional Realtors made this case with real numbers: 32 homes in Ada County under $375,000 and another 564 between $375,000 and $500,000 as of last October, which she says is more than the whole market had at once in 2020. She sells houses for a living, so she has a stake in that argument. It's still a real number and I haven't tested it.
The part I'd push back on is the geography. Those are Ada County numbers, and Boise isn't Post Falls. A listing in Kuna does nothing for somebody working in Coeur d'Alene. Before I accept the argument or reject it, I want to run the same count here, on Kootenai County inventory, and see whether the cheap listings she's describing actually exist in this market.
No answer yet.
Open Over the Rathdrum Prairie aquifer, an ADU still adds people and still adds waste to the same drainfield. No answer, and it lands.
I've been looking at whether the county's one-dwelling-per-five-acres rule should count actual wastewater instead of counting doors. But an ADU does add people, and the density rule is a rough way of capping total load. Anyone who wants that rule changed owes a better measurement to put in its place. I don't have one yet, so I'm not making the argument.
No answer yet.
Open The shortage is caused by immigration, not by zoning. Out of my depth on this one.
This came up in a public thread about Post Falls housing and it drew more support than any supply or zoning answer in that thread, by a wide margin. So it's not a fringe view here and I'm not going to pretend it wasn't said. I also don't have the national data to argue it either way, and a half-researched paragraph on this would be worse than nothing. If I take it on, it'll be with real numbers.
No answer yet.
Open We're already full. Stop building. This is the big one around here.
This is the one I hear most in Kootenai County, and it isn't really an argument about whether more housing lowers prices. It's a statement that people don't want more people. The drive down 95 from Hayden into Coeur d'Alene, the schools, the lines everywhere. I'm not going to answer that with a chart, because a chart doesn't touch it and pretending it does would be insulting to somebody who sits in that traffic twice a day. What I'd say instead is that the people getting kept out are somebody's kids. Two of them are mine. That's not a rebuttal and I know it.
No answer yet.
Open You're turning Idaho into California. I get it. I still don't have an answer.
Different from the one above. That one is about how many people fit. This one is about what the place is, and about who's showing up. I don't have an honest answer written yet. I'll say I understand it, and that my own family has been here long enough that I'd hate to see it change too. I don't think a house my son can afford is what changes it.
No answer yet.
Open I don't want an ADU next door to me. This one's fair.
Renters you didn't pick, another car on the street, somebody behind your fence who wasn't there before. And with the new short-term rental law, a city can't require a permit to rent it nightly, so "it might turn into an Airbnb" is a more realistic worry now than it was last year, not less. That's a real cost of a law I'm mostly in favor of, and I'm not going to pretend it isn't. If I build one and it's a nuisance to my neighbors, I got something wrong.
No answer yet.
Open Growth should pay for itself, and this doesn't. This one points right at me.
I found out my ADU owes no capitalization fee in Post Falls because it shares the water and sewer already on the lot. That's good news for my budget and it's exactly what somebody means when they say new units don't pay their way. My guess is the answer is that an ADU uses capacity that's already in the ground rather than requiring new, which is a different case than a subdivision on a field. I haven't checked whether that holds.
No answer yet.
Tell me where I'm wrong
Two things. I want the second one more.
One: the deal breaker that isn't here. Send it and I'll add it. I'd rather this list be long than comfortable. If you think an ADU is a bad idea, or that building more housing won't help with affordability, that's exactly what I want. The ones I can't answer go up marked open, in your words, not softened into something easier for me to handle.
Two: the entry where you think my answer stinks. Telling me the reasoning is bad on something I've already called cleared is harder to hear but worth it. There is probably a number wrong somewhere on this site. I'd like to know which one.
I'm not doing this to win an argument. I'm about to spend real money on a building in my own back yard based on what's written here, so I'd rather be corrected now.
Three ways to send one: the contact form if you'd rather it stay private, a comment on any post, or a message to the Facebook page. Tell me if you want your name on it. Default is I'll credit you.