Tossing out an idea and looking for feedback

[jamm]

I'm getting fairly close to my desired retirement age and looking at building my retirement home. Living in Michigan and not wanting to fight the winter snow and cold I'm thinking of putting in an underground tunnel from the house basement to the detached garage about 60' away. Anyone here ever done that?

The tunnel will need to be tall enough to stand in and somewhere in the 4' wide range. It will just be a passageway so no finished interior. I'm thinking about using a typical poured wall system or possibly oval precast culvert sections. What are your ideas and thoughts? I would need to have a roof strong enough to withstand a car driving over it.

At the entrance of the tunnel on the house side I'm thinking about making a steel hatch similar to what you see on old submarines that can be dogged and locked down to make the house secure (this will have the cams and gears exposed on the interior for a conversation piece. On the garage side I would have a regular steel door with stairs then leading up to the garage floor. This door would also be locked for security reasons.

The tunnel at this point would just be used as a passage way back and forth but I'm open to other suggestions and uses.

I may be crazy and this may be a pipe dream but I going to give it a shot.

Let's see what you got!

 

[Makoto]

Ever thought about cargo shipping containers? That'd be a heck of a tunnel

I like it.

 

[Toolgarage]

Ever thought about cargo shipping containers? That'd be a heck of a tunnel

I like it.

dammm thats a heck of an idea

 

[NUTTSGT]

It might be alot cheaper to just build a long breezeway between the garage and house. All ground level so less stairs to climb usually something retirees/older generation don't like to do.

 

[Stuart in MN]

I know a mansion here in Minneapolis that was built around 1900, it has a tunnel from the house out to the carriage house. That one was built from brick, but the point being it's been done before so there's no reason it can't be done again.

My concern would be at the garage end - it should be configured so you don't have any problems with exhaust or gasoline fumes getting down into the tunnel (you don't want to pass out halfway back to the house.) build a curb around the staircase into the garage, or maybe even have the staircase come up into a separate entry built onto the side of the garage.

I've thought about this myself (not really seriously, but as a what-if thing) and decided that some of those prefab culvert sections would be the easiest way to do it.

 

[Steevo]

There is a big log home near me that has a ten car garage about 100' from the main house.
They have a level, underground tunnel between structures, that comes into the house basement and into an underground stairwell at the garage end.
They only had to incorporate steel fire doors at each end of the underground tunnel, with good air seals, to comply with local codes.
It is pretty cool, as you can walk from your living room, to the basement, across the tunnel, and up the stairs into the (heated) garage, and never get your feet wet.

 

[Moose97]

My thoughts are; 1.) seriously consider an engineered design before you build. You don't want this thing failing mid-point. 2.) I would think piping fresh air in would be a good idea. 3.) Consider water.

Sounds like a cool idea!

 

[Lkdelta]

Go to some anonymous telephone number, maybe the pay phone at the library...
and call the local codes.
Say "what if"?

 

[justanengineer]

Personally, Id much rather have to walk through the snow than down and up stairs back and forth. To hopefully put this kindly since you said the word "retirement," youre starting to get old and may want to consider planning for days when youre not as physically capable as you are now. The best retirement house is small, single story, and easily maintained IMHO.

As for the tunnel, its relatively simple engineering but I would highly suggest not designing it yourself for insurance reasons.

 

[nolimits76]

So basically a box culvert big enough to walk in. Doable, but I think more expensive than you think. My company does bridge and box culvert work. Not soliciting you. Too far away. Plus it's too small of a project for us.

Anyhow...you will have some serious earth excavation (for a homeowner) to perform. You might need temporary shoring, depending on the soils, exact depths, cut back of slopes, etc. Possible small crane or other heavy equipment to lift the RCB (reinforced concrete box) sections. Once you get it laid in-place, waterproofing will be necessary.

In regards to roads on top, that happens all the time. Talking with a RCB supplier and/or checking MN DOT (dept of transportation) will likely yield some design criteria.

Probably 6-8' tall is the max on a precast unit. More will need to be CIP (cast in place).

Very cool idea, but honestly, I agree about a covered walkway/breezeway that you can heat/cool, if needed, would be more practicable and affordable. If money isn't an option and you want cool and unique, this would work though.

Also, interesting idea about the storage containers. I suspect you MAY be able to use one; however, I'd have an engineer review that for you. If it fails a year or two later and you are in it....you will be a pancake.

 

[jamm]

There is a big log home near me that has a ten car garage about 100' from the main house.
They have a level, underground tunnel between structures, that comes into the house basement and into an underground stairwell at the garage end.
They only had to incorporate steel fire doors at each end of the underground tunnel, with good air seals, to comply with local codes.
It is pretty cool, as you can walk from your living room, to the basement, across the tunnel, and up the stairs into the (heated) garage, and never get your feet wet.

Now that's what I'm talking about!

 

[NHBandit]

Are you dead set on retiring in Michigan ? I always thought I would die of old age in NH in the same house I owned for 32 years. When I retired early 3 years ago we spent a Winter in an RV in southern Alabama. It made us both realize just how much we hated the bitter cold and the snow. 2 years ago we bought a house in North East Tennessee not far from the Smokey Mountains and sold the place in NH. Best thing I ever did. New places to experience everytime we go for a ride, every day is like being away from "home" on vaction because the surroundings are still new to us. It snows very little here and when it does it's generally an inch or 2 and gone the next day. Summers don't seem any hotter than up North but Winters are very mild. Property taxes in NH were 5k a year. Here they are $400. People are nicer, everything is cheaper, there are 100 other reasons why we love it here. TN was also recently voted the #1 best place in the country to retire to. I will say it's not the best place to live for those folks who still have to work for a living. Good paying jobs aren't growing on trees but thankfully I don't need to be concerned with that anymore.

 

[jamm]

Thanks to all who have responded so far, keep the comments coming.

I guess I should have elaborated a bit more about myself. My retirement home doesn't mean that I'm old and fart a lot when I walk. I owned my own precast/prestressed company and sold it to someone who wanted it more than me so I know a fair bit about engineering. I wouldn't install this without engineering oversight. Cost to install shouldn't be a factor as I have "friends" in the business that have the equipment to do the work of which I would likely do myself since I have the time.

Not to worried about codes (I've already scouted out the idea with the building inspector). The water table is not an issue.

I didn't think about fumes or gases getting into the tunnel and venting. That's why I asked you guys for comments. I like the idea of having the stairs in the garage in a side room. Maybe something like a stair well with the door at the top rather than at the tunnel level.

I really don't want a breezeway, I just don't like them and having a tunnel has a "neat" factor that could be very cool or it could turn out to be a stinky musty hole in the ground where the wife stores potatoes. Which is again, why I asked for comments and uses.

Keep the ideas and comments coming.

 

[SGKent]

If you were up near the top of a hill and had no water table or seepage to deal with that would be fine, think long basement. However 100' long I am thinking concrete boat with a bilge pump droning all the time in the wet season. But there is more. I am 63, had several heart attacks sneak up on me the last few years. Stents slowed the damage. So I go out to dinner with a friend and his new bride who has moved back to town. 5 - 10 years younger, haven't seen him since right after 9/11/2001. He has had several heart attacks. Then I think about my grandfather whose heart was too weak to attend my mother's funeral back in the late 50's when he was in his late 60's. Are you sure you want to walk 100' underground to the garage? Maybe a more sunny place where you can get out and walk more frequently might help prolong your life more than a long walk underground. Or are you trying to get comfortable with the end game maybe?

 

[jamm]

Are you dead set on retiring in Michigan ? I always thought I would die of old age in NH in the same house I owned for 32 years. When I retired early 3 years ago we spent a Winter in an RV in southern Alabama. It made us both realize just how much we hated the bitter cold and the snow. 2 years ago we bought a house in North East Tennessee not far from the Smokey Mountains and sold the place in NH. Best thing I ever did. New places to experience everytime we go for a ride, every day is like being away from "home" on vaction because the surroundings are still new to us. It snows very little here and when it does it's generally an inch or 2 and gone the next day. Summers don't seem any hotter than up North but Winters are very mild. Property taxes in NH were 5k a year. Here they are $400. People are nicer, everything is cheaper, there are 100 other reasons why we love it here. TN was also recently voted the #1 best place in the country to retire to. I will say it's not the best place to live for those folks who still have to work for a living. Good paying jobs aren't growing on trees but thankfully I don't need to be concerned with that anymore.

Unless I get rid of the wife (unlikely), Michigan will be the main state we will live in. The wife won't move away from the grandkids.

I agree, Tennessee is nice for retirees. We lived in Murfreesboro for two years while I worked at a plant that provided the stadium risers for the Titans stadium in the late 90s. At that time the infra-structure couldn't handle all the people moving in. While I want to live in a country setting, I still want to have modern conveniences within a quick drive.

 

[Homerr]

How about moving south?

 

[Mike Miller]

Your going to get older, ramps, stairs and ladders will get harder to climb. Trust me, I know this.
Think breezeway.

 

[Playwme]

Why not do the tunnel at ground level? Place your precast culverts and then cover over them with dirt forming a man made hill between house and garage. Put some turf on top, maybe a little rock garden. Hell, if it was me I'd get a few front ends of old cars and have them poking out the front of the hill.
No stairs, no water issues, creates a nice private area behind the mound.

 

[FunkyfullWidth]

You guys are all wimps.... Build a tunnel. That's the coolest thing anyone could ever have for access to a garage.

If water or ventilation is an issue, I don't see why you couldn't run duct work of some sort and maybe even put in a sump pump for just incase purposes. Make it out of concrete, stain it run a string of lights, hell even add speaker pods and play some elevator musac... If you want a tunnel, man... build a tunnel. Its probably just about every boys dream to make a tunnel when they're younger, whether it's in the snow or in the back yard..

 

[Mr_HR]

I just remembered when I worked at an old private school about 100+ years old doing maintenance here in Saskatchewan. The dorms and kitchen had underground tunnels connecting them so students could run around without having to get bundled up for blizzards lol.

Anyways the roof part of the tunnel served as the sidewalk between the buildings. Looking at it you wouldn't know there was a tunnel underneath, except for little cutouts ever couple feet. There was tough thick glass inserted in the cutouts that served as skylights in the tunnel below.

Do what you want, it's a cool idea

 

[JimVonBaden]

I just remembered when I worked at an old private school about 100+ years old doing maintenance here in Saskatchewan. The dorms and kitchen had underground tunnels connecting them so students could run around without having to get bundled up for blizzards lol.

Anyways the roof part of the tunnel served as the sidewalk between the buildings. Looking at it you wouldn't know there was a tunnel underneath, except for little cutouts ever couple feet. There was tough thick glass inserted in the cutouts that served as skylights in the tunnel below.

Do what you want, it's a cool idea

Very cool idea!

Have a tunnel and a sidewalk in one! I really like it! Simple and effective.

Jim

 

[Zippercat]

Probably could buy a house in Florida for the cost of the tunnel.

 

[superfish]

I think the tunnel is a neat idea. On the other hand, you did say that you are thinking of building your retirement home. Why not just build the garage attached or closer to the house. Up here in Vermont most of the older houses are built so that the house is connected to the garage which is connected to the barn. No need to go outside at all.

 

[Orange65]

Buried cargo containers will collapse under the pressure of the earth- heard of this by people that tried it.

Use concrete, provide good ventilation- sounds like a great idea!

 

[woodrail]

I've done some similar work to what you describe. Here is a section to give you some thoughts.

Personally, I'm liking the idea. Especially if you can get it done calling in favors!

I also would go wider than 4'. Make it comfortable and employ the space. Nothing wrong with having 60 feet of wall storage! Also, it would make a nice tornado bunker.

On the garage end, I would carry the steps up at least 12-24 inches above grade. Not only will this stop gases from drifting down into the tunnel, it should help with the cold.

Forget about the container idea. By the time you rebuild it not to be a death trap, you could do this cheaper.

 

[stingry]

Personally I don't like the idea of the tunnel but if the OP wants one fine. I toured an underground missile silo once and the connecting tunnels were made of what looked like big culverts.

Cheers
Steve

 

[sberry]

Put elevators at each end.

I don't think its practical but that wasn't really the question. The only stumbling block is the cost and his question didn't start with,,, how cheap? It could be a great shelter, storage or vault. Great raceway for the utilities and depending on location could have other neat design options.

It could be done so generally it wasn't apparent that it was there. I can see now I need to get some drawing program here, a lot of design issues come up could easily work on.

 

[sberry]

I am with Woodrail here, go to all the trouble it aint but a pinch of **** more to make it really useful by going wider. Me too, full running shelves, motion detector lighting, above freezing, consistent atmosphere.

 

[sberry]

Where in Michigan might this be?

 

[vetron]

assuming you can afford it, then do it, why not!
i'd suggest long ramps at each end so you can ride a scooter down into the tunnel then up the other side. or elevators, as suggested. thinking way way ahead, not just today. great place for cold storage, wine cellar,etc.
thinking of the movie dirty dozen, have some vents thru the top. make them so no one can drop grenades in ouch!

 

[signcrafter]

Guys, he stated that he was in the precast business and can call in some favors. So it won't cost him much and will be pretty easy to do, especially if he went with oval precast like he mentioned. He's just trying to work out a few details, pretty sure he can handle the actual tunnel. Heated golf cart won't work in MI snow when there are times you can get well over a foot. Unless you put a lift kit and studded tires on it! He said he doesn't want a breezeway, says he doesn't like the looks and he also mentioned he needs to drive a car over it so the breezeway would prevent that.

I would go one step further and make it big enough to run a golf cart thru it! You will have to figure something out for the garage end like a ramp or service elevator to get the golf cart up to ground level but it will be nice as you get older. Also be nice to transport things from garage to house. How long is your garage? If it's long enough and big enough (I'm guessing a bigger shed type garage) I would make a ramp inside with storage above it.

 

[theoldwizard1]

It might be alot cheaper to just build a long breezeway between the garage and house. All ground level so less stairs to climb usually something retirees/older generation don't like to do.

Zoning nightmare
First to flood
Just as cold
Not a good idea
If you can't handle the cold you likely can't handle the stairs.

I'm going to join the nay sayers !

It is going to cost a lot more than you think (unless you own a construction company with back hoes and the ability of pour concrete walls and floors)

In most of MI, the frost level is about 36". 48" further north. You really need to be below that. Water intrusion may be a major issue, so you end a good external weeping system and water proofing.


Spend your money on something else more enjoyable !

 

[sberry]

It depends on how much money he has? Probably about the cost of a new Cadillac that is scrap in short order, to some of us it would be a lot but to those with real money not much especially since I doubt the op is not a beginner. About the cost of a typical home basement

 

[signcrafter]

I'm going to join the nay sayers !

It is going to cost a lot more than you think (unless you own a construction company with back hoes and the ability of pour concrete walls and floors)

I guess I should have elaborated a bit more about myself. My retirement home doesn't mean that I'm old and fart a lot when I walk. I owned my own precast/prestressed company and sold it to someone who wanted it more than me so I know a fair bit about engineering. I wouldn't install this without engineering oversight. Cost to install shouldn't be a factor as I have "friends" in the business that have the equipment to do the work of which I would likely do myself since I have the time.

Sounds like he has some favors he can call in so won't cost much to him.

 

[Jagmandave]

If you decide to do it, please be sure to document everything here so we can watch, much like the concrete bunker thread.....

 

[Krash Kadillak]

There's one of these in the Garage Gallery section. Large garage with a tunnel to the house basement. Can't find it right now. Do a search. I think it's in the midwest somewhere....

 

[ptgb]

I'd buy an old Honda Civic and install a remote starter on it.

Start it up while you're drinking your coffee, let it get warm.

Enter it.

Drive to garage.

Walk into garage.

What, $700 total?

 

[DIC]

How about a heavy coat and a zip-line

 

[ihredo4]

jamm.

I love the idea you have. The facts are you are familiar with the industry, have friends for help, the home appears to have or will have a basement and the garage is about 100 feet away. I would go for it.

Maybe have a tunnel that would angle up behind the garage and enter on a landing just above the garage floor.

Use an electric golf cart or shuttle of some sort that would help moving groceries or whatever to the house. Plug ins on both ends to keep it charged.

Run utilities thru it for the house/garage. Adds tons of wall space for storage.

Incorporate some sky light ports to get light into the passage.

Heck design it as a long thin storm shelter with access on both ends.

If the terrain dictates it place the garage say 10' below the main floor on the house and run the passage flat from basement to the garage or maybe slightly down hill to the garage.

So many things could be done with this I would do it in a heartbeat.

Good luck and keep us posted.

 

[jamm]

How about moving south?

I hate the heat, humidity and geezer golf cart communities more than snow. No offense, just not my cup of tea for a permanent home. Plus we would be away from the rest of a close knit family.

Why not do the tunnel at ground level?

Novel idea but I don't want to raise attention to the passageway and it would negate being able to drive over it.

Very cool idea!

Have a tunnel and a sidewalk in one! Jim

I like that idea, I'll need to follow up on that.

Probably could buy a house in Florida for the cost of the tunnel.

The house would be pretty small because the additional costs would not be much more than adding an extra basement. Having a narrow tunnel also helps with the engineering issue of roof thickness to support vehicles driving over it. However, your idea got me to thinking about a basement under a portion of the garage floor. Prestressed plank could be used it's fairly common and cheap.

Personally, I'm liking the idea. Especially if you can get it done calling in favors!

On the garage end, I would carry the steps up at least 12-24 inches above grade. Not only will this stop gases from drifting down into the tunnel, it should help with the cold.

Thanks, I like the idea about the steps being raised and will consider it.

I am with Woodrail here, go to all the trouble it aint but a pinch of **** more to make it really useful by going wider. Me too, full running shelves, motion detector lighting, above freezing, consistent atmosphere.

The tunnel will pass from a house basement to a garage so storage space at either end will not be an issue. Plus the house will have an attached garage for storage also. I like the motion detector lighting idea and will check into them. I might even be able to tie it to an alarm system.

Where in Michigan might this be?

Between Kazoo and Grand Rapids.

i'd suggest long ramps at each end so you can ride a scooter down into the tunnel then up the other side. or elevators, as suggested. thinking way way ahead, not just today. great place for cold storage, wine cellar,etc.
thinking of the movie dirty dozen, have some vents thru the top. make them so no one can drop grenades in ouch!

A ramp could be an option at the garage however, the other end starts in the basement and would require a really deep tunnel. You mentioned the underground bunker in the Dirty Dozen movie and surprisingly I got my tunnel idea from watching Stalag 17 as a kid.

If you decide to do it, please be sure to document everything here so we can watch, much like the concrete bunker thread.....

Definitely. Mine however will not be as spectacular as the concrete bunker.

I'd buy an old Honda Civic and install a remote starter on it.

Start it up while you're drinking your coffee, let it get warm.

Enter it.

Drive to garage.

Walk into garage.

What, $700 total?

Wouldn't it be easier to warm up the Bentley in the house garage and then drive it into my shop. Seriously though, I don't have a Bentley and a Civic doesn't have the 'cool' factor of a tunnel that few will know is even there. Plus I'll likely traverse between the house and garage numerous times each day and during one of those trips I'd lose the car keys.

How about a heavy coat and a zip-line

If you could figure out a way for a zip line to work in both directions and start out underground in the basement, that would be totally awesome.