Chimney closer than 10 feet to neighbor

[StoveHopeful]

Evan here, a first time builder working on my Vermont 8x10 tiny house to live in while unemployed. I've been planning to install a wood stove in my tiny cabin for this winter but just learned about the rule that chimneys be higher than anything within 10 feet. My tiny house is not subject to any building codes, but it is next to my brother in law's house and the location in the cabin for the stove would put the chimney about 8.5 feet from his closest exterior wall. I was wondering what the justification is for the 10 foot rule (fire safety? Chimney efficiency? Something else?) I will be moving the tiny house next year so it's only an issue between now and May, but I would love to have the stove installed for this winter. I appreciate any insight you might have for me! Thank you

 

[gthomas785]

The 10ft rule is mostly about chimney performance but also safety. Walls in close proximity to the flue exit can cause weird pressure pockets that would cause your chimney to backdraft or be sluggish. This is not only annoying and will cause poor stove performance, but also a hazard for CO poisoning if the draft reverses while you're sleeping. You also don't want the chimney to be too close to a combustible wall since an occasional ember may fly out and start a fire outside.

Since you're already at 8.5 feet, it might work fine where it is. But is there any way to just move your house over a little so it's not quite as close? Then problem solved.

 

[SpaceBus]

To my knowledge the ten foot rule mostly applies to the outlet. Elsewise you could not install the chimney on the side of a structure. The top of the chimney must be two feet taller than anything within ten feet. It will cost more, but you might have to make the chimney taller. Is this chimney exterior or through the roof?

 

[Maj92az]

Sometimes we never know what goes into these codes- like in aviation maybe often written in blood as they say??

But if it was truly safety and ember protection.. two feet higher than something sure isnt that great either! I have heard it's mostly backdrafts. My neighbor said they had a new stove once (met all requirements) but was super smelly. The chimney was at the bare minimum and after they added 3ft it went away. It's not ideal but maybe an offset in the pipe worth 1.5 feet??

 

[StoveHopeful]

The 10ft rule is mostly about chimney performance but also safety. Walls in close proximity to the flue exit can cause weird pressure pockets that would cause your chimney to backdraft or be sluggish. This is not only annoying and will cause poor stove performance, but also a hazard for CO poisoning if the draft reverses while you're sleeping. You also don't want the chimney to be too close to a combustible wall since an occasional ember may fly out and start a fire outside.

Since you're already at 8.5 feet, it might work fine where it is. But is there any way to just move your house over a little so it's not quite as close? Then problem solved.

Thank you @gthomas785 for your reply. Oooh yes we definitely dont want any CO issues especially while sleeping! I will definitely install a monitor and probably sleep with a window cracked for safety. I was hoping 8.5 feet might work since we are close to the 10. With how cold it gets here in winter I wonder if an ember would even start a fire if it reached the house after flying 8.5 feet - embers from the outside bonfire pit never seem to start fires out here even when people/things are closer than 8.5 to it. We were thinking about moving the house over a little bit, but it would take a lot to move it and relevel the foundation - the ground any further from the main house gets all wonky. Planning mistake on our part. I will keep the forum updated!

 

[StoveHopeful]

To my knowledge the ten foot rule mostly applies to the outlet. Elsewise you could not install the chimney on the side of a structure. The top of the chimney must be two feet taller than anything within ten feet. It will cost more, but you might have to make the chimney taller. Is this chimney exterior or through the roof?

Hi @SpaceBus ! Thank you for this response. Yeah, that is my issue - the outlet of the chimney would be taller than the 10 foot roof of my tiny house, but the house next door (my brother in law) is 8.5 feet away and 2.5 stories, probably 15 feet or so taller than my roof, so we cant extend the chimney to be taller than the main house. The chimney is planned through the roof but if necessary we might be able to rearrange the interior of the house and put the chimney at the furthest point from the main house and run it through the wall, I just heard that wall exits are more expensive and dont work as well.

 

[StoveHopeful]

Sometimes we never know what goes into these codes- like in aviation maybe often written in blood as they say??

But if it was truly safety and ember protection.. two feet higher than something sure isnt that great either! I have heard it's mostly backdrafts. My neighbor said they had a new stove once (met all requirements) but was super smelly. The chimney was at the bare minimum and after they added 3ft it went away. It's not ideal but maybe an offset in the pipe worth 1.5 feet??

@Maj92az Thank you for responding! I wasnt able to find any info on the code rationale really so this forum is very helpful. You are right, two feet higher than my roof isnt a whole lot! Ive never heard of a pipe offset, what does that look like? I will also Google it to see if I can find any info.

 

[Smolder]

I would think your chimney must be 2 feet taller than any other structure it is within 10 feet of. If my neighbor had a short house and their chimney was pumping smoke at at my second story bedroom window level I definitely would not like that.

 

[gthomas785]

Yeah, the ember flying out the chimney and starting a fire is a pretty remote risk, but it has happened to people. Also pay attention to any windows on your BIL's house, you don't want to be blowing smoke into their living room.

You will be fine if you use common sense, do not place the chimney right next to combustible objects or windows, and pay attention to where the smoke is blowing on the first few fires. Just be prepared to modify your setup if it's not working right.

A straight run up and out the roof will usually draft better and be easier to clean than thru the wall, but both can work.

 

[rwhite]

I wouldn't want a chimney cap within 10ft of my upper floor. I can imagine the smoke will travel right into the house.

 

[Sawset]

I wasnt able to find any info on the code rationale

Here is a primer on how wind may effect your chimney placement:

A non-commercial service in support of responsible home heating with wood - How Wind Affects Chimney Performance

The Wood Heat Organization was formed to support the public in the responsible use of wood energy in the home. We fulfill our mandate by providing reliable information, by conducting research into wood heating-related issues and by representing the public interest in discussions of policies that...

woodheat.org

 

[bholler]

Everyone seems to have covered the reasons for the codes pretty well. But I want to add that the idea that codes don't apply to tiny houses is completely false. They are classified as mobile homes and therefore need to follow those codes.

 

[StoveHopeful]

@Smolder that is correct, it needs to be higher than anything within 10 feet. In order to do that I might need to move my tiny house 18 inches, or rearrange the interior to move the stove further from the main house. I was thinking about the smoke issue too and might need to just see which way the smoke tends to blow in the area to see if it will be an issue.

@gthomas785 luckily almost everyone lives and sleeps on the first floor, and the kids room is on the opposite side of the house so Im hoping smoke wont be an issue but it could turn out to be a problem that we will have to work around later like you suggested. We do have a few windows in the tiny house. Im trying not to run the stove pipe right in front of the windows, but was thinking I could use an insulated (double wall) pipe on the interior if I do need to run the pipe in front of a window - do you think that would still cause the window to crack?

@Sawset thank you for that resource I am reading it now and learning a lot. It says that "Hearths installed in single story sections of two story houses almost always perform badly," which is basically what I am planning to do. My tiny house is basically a first story addition to the main house, just with a few feet of dirt between the structures.

@bholler I am definitely learning a lot through the forum! I know that codes apply - I think my tiny is technically an accessory dwelling since its on skids and not wheels?

 

[gthomas785]

I don't think you need to worry about the windows in the tiny house. My concern was about smoke getting into a window, not about damaging the window. You can run your pipe wherever you want inside as long as you meet the clearances.

 

[rwhite]

Although the potential exists for a safety issue with smoke entering the adjacent house I think the nuisance factor is a bigger problem. If your BIL has any soffit or gable vents the smoke is going to hang under the eaves and permeate everything.

 

[StoveHopeful]

@gthomas785 and @rwhite it definitely sounds like smoke near the main house window is a key reason to have the tiny house chimney 10 feet from the main house. Does smoke dissipate significantly over ten feet or even if I move the house to be ten feet away do you think it might still be a problem? I'm wondering if perhaps ten feet is the code but would it really take fifty, a hundred, or more feet to really not have my smoke interfere with the house next door?

 

[gthomas785]

@gthomas785 and @rwhite it definitely sounds like smoke near the main house window is a key reason to have the tiny house chimney 10 feet from the main house. Does smoke dissipate significantly over ten feet or even if I move the house to be ten feet away do you think it might still be a problem? I'm wondering if perhaps ten feet is the code but would it really take fifty, a hundred, or more feet to really not have my smoke interfere with the house next door?

It all depends on the wind. That's why I said you will have to see how it functions. Do you know if your tiny house is on the typically upwind or downwind side of the larger house?

 

[StoveHopeful]

It all depends on the wind. That's why I said you will have to see how it functions. Do you know if your tiny house is on the typically upwind or downwind side of the larger house?

@gthomas785 makes sense to me - and I'll have to check today, I haven't paid attention before but there is a big wood stove in the main house so I should be able to see the smoke. I'll be up on the roof and installing windows so plenty of time to take a gander

 

[begreen]

There will be days when the smoke is annoying to the in-laws. Smoke doesn't always goes straight up. On some calm, low-pressure days it may actually sink and hang around the yard, especially if this is in an area that gets temperature inversions. A decently insulated and sealed tiny house is not hard to heat. Consider using an electric or small propane heater instead this winter.

 

[StoveHopeful]

There will be days when the smoke is annoying to the in-laws. Smoke doesn't always goes straight up. On some calm, low-pressure days it may actually sink and hang around the yard, especially if this is in an area that gets temperature inversions. A decently insulated and sealed tiny house is not hard to heat. Consider using an electric or small propane heater instead this winter.

@begreen I never knew smoke was so versatile! It has been a big journey figuring out how to heat the tiny. I was planning to use electric or propane for a while but then realized it would use my house's entire 20 amp electric power, and a few people on the DIY electrical forum steered me away from space heaters like electric fireplaces. It sounds like unvented propane is not very safe in a well sealed tiny house and the vented options are quite expensive plus the cost of propane. I've tried a few BTU calculators that say I'll need about 5000 btu but I won't really know until I'm in the house I guess. I've still got a few days or weeks to figure it out, eek!

 

[begreen]

20 amps is tiny, even for a tiny house. A toaster, microwave, etc. will tax that system if there are other loads running at the same time. How will you be cooking?

I was thinking an oil-filled electric radiator as the heat source or a small vented propane heater. The propane system will cost to install, but so will a properly installed wood stove system.

 

[Maj92az]

This very moment I'm looking my neighbors smoke (200 yards away) and with no wind it's going up at 30-45* angle. 30ft in front it must be 100ft or more higher. 2 minutes later its rolling off their roof and I see it in the sidewalk 3ft off the ground right at the front door. Yeah smoke certainly has it's own plans.

 

[SpaceBus]

I lived in an RV for two years with one other adult and three dogs, albeit in NC. We heated it with a small infrared heater with a built in blower and the RV built in propane furnace. I would estimate the onboard propane heater at 80% efficient and it did distribute through the floor which helped. Even without a skirt and opening the door all the time to let dogs in and out we heated the 38' bus with one 20 lb dot tank per week and that included cooking and heating water.

With insulation the propane heating costs would be very minimal. You could also consider a boat stove that burns heating oil or diesel. In propane I would only consider vented or an exterior unit. Solid fuel seems impractical for your application. The exception might be a pellet stove.

 

[Sawset]

Once in a while I'll stop and watch smoke stacks, just to see what the air is doing that day.
The ride to work here is interesting in the winter. There is a guy burning wood, and the smoke plume varies depending on conditions, sometimes straight up, sometimes straight out and level and traveling miles from the source at ground level, sometimes loops straight down and hits the ground and stays there.

 

[Sawset]

I lived in an RV for two years with one other adult and three dogs, albeit in NC. We heated it with a small infrared heater with a built in blower and the RV built in propane furnace. I would estimate the onboard propane heater at 80% efficient and it did distribute through the floor which helped. Even without a skirt and opening the door all the time to let dogs in and out we heated the 38' bus with one 20 lb dot tank per week and that included cooking and heating water.

With insulation the propane heating costs would be very minimal. You could also consider a boat stove that burns heating oil or diesel. In propane I would only consider vented or an exterior unit. Solid fuel seems impractical for your application. The exception might be a pellet stove.

We have a Wave6 catalytic heater for the RV. We're good to outside temps in the teens. It does produce some condensation at those temps, but with better insulation we could alleviate that. The heater sips fuel though, and is silent.