It seems to me like the wrong way to heat a garage. What would the advantage be, car comfort? If the sub contractor can't tell you the advantages he is may be just trying to sell what he installs. Ask the contractor for alternate proposals so you can compare them.

We haven't spoken directly to the sub contractor, only through our builder. A lot of homes here in Minnesota have some sort of heat in the garage because of the cold temps and since we're having concrete floors, perhaps they worry about the thermal mass aspect of the cold coming into the home.

We'll definitely ask the builder to get the pros and cons for it. Thanks for your insight macv. We just don't have any friends or family who are building that we can ask specifics without having an anterior motive of selling us something.

There is a lot of tough decisions with building, we just want to make sure we do the things you really SHOULD do when you building because it's so much easier and costs less in the beginning. It seems frivolous--we're just happy to have both cars under a roof!

I am going to say it. Yes radiant heat in the garage (without a workshop) is frivilous. If anything, you would do forced air and heat it up a bit in the mornings. But to heat it all the time so you could walk barefoot to get something you forgot in your car seems frivilous.

Your garage will be warmer than the outside. Insulate it and you might be 40 degrees on a zero degree morning.

The $3000 is only part of the issue of course. The ongoing cost will make that seem like chump change.

I live and build in a usually cold climate. Only if you were working in the garage regularly might it make any kind of sense to use radiant in the floor.

More practical if you were to regularly use the garage would be a gas-fired ceiling mounted infra red heater. They warm the space rapidly vs. radiant. My heating contractor always advises anyone considering garage heat to put in the piping, so you have the option later.

The biggest drawback to heating the garage are the doors. Even when they are advertised at xR value, there's no independent testing and the seals are never satisfactory. Take a look at commercial facilities and you'll see very heavy seals--still not that effective.

On one house I built for myself, I included a 30 AMP plug for an electrical heater. It worked fine for occasional use, so I could at least get the temp up to a balmy 0ËC.

Hi Heather,

We are doing radiant heat in the basement floors as well, but not on the main floor. We considered doing radiant in the garage as well, but the cost was quite a bit (we have a 4-stall). We are instead doing a ceiling mounted electric heater. Total cost including the wiring, heater, and a thermostat will be around $500. We can set the thermostat at 40 degrees or so to take the chill off, but it will be fairly cheap to run and cheap to install. We did quite a bit of research into radiant in the garage and in addition to the high up front cost, it was going to cost a lot to run and even keep the garage at 40 degrees.

Personally, I've been in many garages with these ceiling mounted heaters and they feel wonderful. Definitely better than no heat there and quite inexpensive to do. Also, you can just rough in for a ceiling mounted heater and easily install it later to save a bit of money now. You can see how your garage feels in the winter and decide if you really want it or not. My MIL really likes not having a heater in her insulated garage because she can keep extra pop and refrigerated items out there during the winter time without having a second frig! She lives in Iowa.

Hi - We are in Southern Calif., so our weather and yours are very different. But we did not do radiant heating in the garage, or any kind of heating, and my husband regrets it. Because it's a 4-stall garage, he does a lot of workshop stuff out there, so that is different, too.

We just finished building a house that sounds a bit like yours. Modern, flat roof, concrete floors throughout, radiant heating beneath. I have a thread on this forum that shows our house, if you want to look at it... something like "look at my house." It leads to a competition site our son entered the house in but just ignore that and look at the pictures if you want to see it.

Good luck - sounds like fun! I don't really think we want to start over, but it was a pretty amazing journey, start to almost-finish.

I think heating the garage is a good idea in cold climates. But is radiant heat the most efficient way to do that?

Most definitely I would be able to shut off the garage heat, of whatever type, separately from the living quarters if desired. Who knows where energy prices are headed or what regulations may be imposed on indoor temperatures or the permissible heated area. We are going to be regulated to the finest details of our lives.

YOu'd be far better off to put that 3K into better quality insulation for the garage (especially ceiling and house/garage common walls), including better quality doors. THen get a cheap ceiling heater.

Thanks everyone for your responses--we've been chatting about it all weekend and it was SO nice to come back to the forum and see the replies. We had pretty much decided against radiant floor heat in the garage when we got all of your responses.

We had decided to do insulation on the ceiling and the two garage walls that didn't have insulation and if at some point we think we need a heater, we'll have one installed at that point.

Shelly_k-->I really appreciate your thoughts since I know you're in South Dakota and very similar to our winters temps. We just can't justify it and would rather use the money for other overages or splurges.

Again, thank you everyone--I'm sure I'll be popping back with questions :)

Heather J in MN
www.1070burgess.com

We needed to heat our garage but used a ceiling mounted heater that uses one of the hot water zones. Since you will have radiant elsewhere this should be an easy add-on, and much less expensive than radiant in the garage. We keep ours at 47.

Our garage (and most of our house) is built of ICFs and has insulated garage doors. The lowest temperature we have had inside it was 40 degrees when it was 20 below outside. The rest of the time it is in the 50s or 60s during the winter here in Michigan. We always close the garage doors immediately, and the heat of the 2 vehicles helps warm it up when we return home. The garage has 2 walls in common with the house, which also help to keep it warm. It has 4 small (2'x2') windows facing SE for natural light, that get warmth on sunny days. We lose some heat because of them the rest of the time, but not as much as we would if they were as large as many that we've seen. DH ran a gas line to the ceiling of the garage in case he ever decided he wanted heat out there. Since he has a large workshop downstairs, this was a bit of a redundancy!

Do you have your laundry on the first floor near the garage? If so, wouldn't you be able to clean your paint brushes there? We put a deep wash tub in ours, and that's what we do. That way you wouldn't have to worry about pipes (or you!) freezing.

Why are you building a house with a flat roof in Minnesota???

Anne

Hi Anne!
Actually, we will have our laundry on the first floor (main level). As you walk in from the garage, you go into a small mudroom/pantry and then when you go left from there, you will walk into our walk in closet that has our laundry in it.
We have a utility sink planned for the garage on the same wall that the laundry will be on. Do you think the pipes will freeze to the utility sink? This wall is a shared inside wall so will be insulated and we are doing spray foam insulation. For the two walls that will not have the spray insulation, we'll try and do regular insulation and hopefully in the ceiling as well (flat roof design).

We keep hearing the "a flat roof in Minnesota" argument from everyone, especially our fathers, but the technology is much different from the times of the 50's when it was popular. I'm not worried at all and can't imagine our house design with anything different :)

Heather J in MN
www.1070burgess.com

Will the pipes freeze? Don't know, but we seldom get 20 below temps, and when we do, it's not for longer than a day or two. I hear it's colder in MN ;o) I don't think the insulation in the garage will save you on this, but maybe someone else knows more about that than I do. If you wash out paint brushes often, I'd redesign the house so that the laundry is next to, but not in the WIC, use the wash tub there, and not have to worry about frozen pipes in the garage. If I were off on a vacation during the winter, and heard that there were subzero temps at home, I wouldn't want to be wondering if the pipes had frozen.

As for the technology that will allow you to have a flat roof--repeat to yourself every day, "Water always wins!" and see if you are still comfortable with the idea of a flat roof in an area with heavy snow loads after several more weeks of thinking about it. All it takes is one small penetration, and you'd have to catch it before there was any damage--hard/impossible to do. But perhaps others here can comment on the technology you're talking about.I can see where it might be ok for a while IF the installation is PERFECT, but none of our subs were perfect. One thing we learned was that everyone talks a good game when they are trying to get your business, but the reality of the build is that mistakes, known and unknown, may be things that you never even imagined. The only place I'd even maybe consider building a house with a flat roof is in the Southwest, IF the area had almost zero rainfall or snow. Why ask for trouble.

Anne

Hi Anne,
Looks like we're both online tonight :) I was actually in the middle of writing to our builder and got your email so I included a question about the utility sink in the garage. We're in the building stage now so no way to change the design. We actually had the utility sink in the "mud room" and decided we didn't want to see it every time we walked in from the garage, so moved out there. Thanks for throwing that thought out there! I'll let you know what he comes back with.

I understand the concerns for water and snow on the flat roof, but I really do feel confident in the design and materials that we will be using. Heck, we've got neighborhood friends who had roof leaks when their roof is pitched about 60 degrees because of snow dams that form in the winter. From the street, our home will look as though it is flat, but in actuality it will be slanted slightly to allow for run off to the eaves. We're using an EPDM membrane that will cover the entire roof which allows for no seams. Even with those two things, I wasn't totally sold until I learned that the parapet for our roof is only 6 inches high, which means the snow load for our roof will be very minimal in comparison to other flat roofs or even pitched roofs.

I'm strictly a contemporary design freak and can't even imagine living in a home that doesn't have a flat roof....I know it sounds crazy but I love that design aspect and haven't been able to stray from it, even when we were just looking at homes to remodel--I was dead set on changing the roof.

I appreciate your thoughts on it though and understand the risks, but like I said feel confident in our choice. But if for some reason I'm wrong, you and the board will be the FIRST to know ;)

"...it will be slanted slightly to allow for run off to the eaves."

Well, that's not flat! Since the water has somewhere to go, you'll probably be ok.

Good luck with your build.

Anne

You might like to read this blog.

They did a modern in Minnesota as well. Flat roof and all.

http://moderninmn.blogspot.com/

Well I am going to be the one to go against the grain here. I would absolutely put radiant in the garage. I just did in my new build. The nice thing about radiant heat is the near instant heat recovery after opening and closing the doors. You just can't beat getting in a nice warm car when it's 20 derees outside.

You just can't beat getting in a nice warm car when it's 20 derees outside.

You can buy a plug-in (to AC circuit) car warmer for less than $50 that'll do the same thing. Of course, there's still that grueling walk through an unheated garage!

I have to go against the grain, as well. But it depends on what your heat source is. If your radiant is water, heated with firewood, the continuing cost issue is a non-issue.

If you are heating with something else--propane, for instance, you'll have to factor that in.

I am in Kansas City, not as cold as MN, but similar type climate. Our house is heated with radiant water tubes, which are heated with a firewood boiler. We have about 6600 sq ft of radiant tubes. Plus we have a basement garage that has the tubes. We did not run tubes in the upstairs garage. I wish we had.

As someone familiar with radiant heat, you know that opening the garage door really isn't the issue. The heat is in the concrete. It takes hardly any time to heat back up that space because it's radiating from the floor. From the floor...up. So even if the door is open, you still have the heat in the floor.

It sounds like you may have made your decision, but I thought I would share my experience, seeing as we have radiant, and we live in the same sort of climate, although not as cold.

It's not really about "heating" your garage. It's an extension of your house, and thus a buffer to the outside.

Your contractor is right, now is the time to put it in. I regret NOT putting it in.

What is the breakdown of the $3K costs? Does that include the slab insulation or is that going to be installed regardless of whether you heat the floor or not. If its in there already, simply add the tubing now for $700 and dont complete the balance of the installation. At least your can add it at a later date. Once you pour the floor, you never get another chance if you truly want radiant infloor hydronic heat in your garage.

I'm getting nervous about how much folks are saying it will cost to run the radiant heat, but we decided to put it in our garage. We'll see how that works out next winter when we're finally in the house. We had the same dilemma, and eventually opted to put it in. We live in WI, and after the last couple of ridiculously cold winters, we decided that a heated garage is worth it. I admit I didn't research all the methods of heating the garage, and just went with the radiant heat that our builder recommended, but it sounds like our costs were half of what you were quoted; so, it didn't seem like it was as bad. We previously had a garage that was just insulated and drywalled, and even in the coldest weather, it was somewhat bearable. I think it felt more like 30 degrees rather than -5! We are currently renting a home with no insulation in the garage, and man, does that suck. We have 4 kids; so, it's always a major scene and ordeal to get everybody loaded into the car. Those few minutes of excrutiatingly cold temperatures are miserable, and the car is ice cold. It's so cold in the garage that one morning we found that my son's boots were literally frozen to the garage floor. Now, that's an uninsulated garage. Another reason we decided to add the heat was that other homes in our neighborhood had it. We just felt like in the long run, it might be a good thing to have, especially in this cold climate. We were on the fence about it though.

You all are a bunch of pansies - move south if you don't like the cold.... Do you drive to a heated garage - no. You drive somewhere where you park outside. So don't you wear clothing so that you are comfortable?

Next we are going to be air conditioning our garages in the south.

Frankly - does noone care about the environmental costs of heating a space you are in for 5 minutes (if that) a day?

(not withstanding the wood boiler).

I'm not offended by being called a pansy. :)

A rose by any other name...

A garage is farm more than a place to park your vehicle here in the north.

It is a mechanics shop, a woodworking shop, a place to dry all your snowmobile or skiing gear. An moderate place for your freezer. I could go on and on. Parking your car is only one small part of what we use a garage for.

Gee Mr. Cary, kind of harsh. :) Next time ask more pointed questions so you know what we're about.

The reason we're doing radiant heat in the entire house is for energy efficiency. The basis of my original question is should we extend it out to the garage since it can't be 'undone'. Radiant heat is a very efficient way to heat our home and once we can replenish our savings, we will be adding solar panels to PAY for the cost of heating the home. Can't get much more environmentally sound than that.

And as far as warmth, we're not talking 70 degrees here, we're talking keeping it at 40-50 degrees so the utility sink out there won't freeze and not allowing the cold to come into the home through the walls of the garage or the door that leads out there. Remember, our winters are sometimes almost 6 months long and we spend several weeks a year below zero. We're far from pansies.

In Minnesota it gets cold and since for the FIRST time in 16 years, my car is going to be inside a garage, I wanna make sure I'm doing it right, efficiently and the way I live, frugally. Plus, the garage for us, will be an extension of our living space throughout the year. We are building a modest home and having that extra 551 square feet, might just come in handy.

Just some added thoughts from me. Thanks everyone for posting. We're pretty much leaning towards not installing it but thanks to rollie and his input about just laying the tubing, I'm going to inquire about it and see what the costs might be. I can't believe we didn't think of this sooner! Thanks!

When we built our 30 x 55 shop/garage 13 years ago, we put in PEX for radiant heating. It cost us around 1K then for the materials with a DIY install. Probalby cheaper now due to supply and demand issues. We also used 2x6 construction, full cavity insulation and foil faced foam sheathing on the exterior and the two 20'W x 8'H garage doors are R 15.

We've never had to hook up the radiant heat. THe shop is so well insulated, that even in a cold winter (0° for a day or two is cold for us!) with zero heat, it never falls below 40°. THis year has been the coldest extended weather that I can recall. Lots of extended time well below freezing for weeks on end. (Mostly between 20° and 30°) We've been able to work in the shop in shirt sleeves by heating it to around 62° with 2 1500 watt electric heaters. We only actively heat it maybe 10 hours a day, and it doesn't fall below 50° overnight, even after 14 hours with no active heat.

This is why I say that your money would be better served by better insulation for the garage than by radiant heat for it.

I'd definitely put radiant in as long as you can run it as a separate zone with its own thermostat. We're nearing the end of our build and put in geothermal forced air, but radiant for the basement floor and the garage floor. We're in southwestern Pennsylvania. Make sure you put XPS insulation under the floor (I used 2 inches for the garage, 3 in the basement). For now, our garage is the workspace for painting all the trim going in to the rest of the house. It's a very comfotable space now with the temp set about 60. I'll likely keep it around 50 later if the thermostat lets me set it that low. Walls are 2x6, garage doors are 2" thick R-15.

we're talking keeping it at 40-50 degrees so the utility sink out there won't freeze
Three grand to keep an occasionally used utility sink happy sounds a little steep to me. Put in a heavy duty laundry tub or extra utility sink.

not allowing the cold to come into the home through the walls of the garage or the door

In winter, your garage will be warmer than the rest of the house, not colder.

"not allowing the cold to come into the home through the walls of the garage or the door". What will prevent cold from coming in through the walls not protected by the garage? My attached garage has R-19 in the ceiling, R-11 in the walls. The R-11 was donated to me by a relative who bought far too much for his job in the 1970s and had it stored since then. The garage doors are insulated, two doors 9 wide, 8 high instead of one really wide door. The coldest temp registered in the garage is 43 deg with outside at 10 deg. No heating system or equipment in the garage.

In winter, your garage will be warmer than the rest of the house, not colder.

Should be: "warmer than the rest of the outside of the house"

Ok - I'm a little harsh. When you say solar panels - I hope you are not talking PV because that would not be the best way to do it. Geothermal probably makes the most sense and maybe thats what you are talking about - then PV may make sense.

A flat roof is not ideal for PV or solar thermal panels(unless you tilt them) - I'm just saying....

As an aside - if you can call it that. If you are mounting a garage sink on a wall that is in common with the house, it would be easy to frame out the base and insulate it. If you could do it right (ie no insulation on the house side), it would be in the thermal envelope of the house and wouldn't freeze in the coldest of winters. That would cost

Of course, it also depends on what is above and below the garage. In our case, there is a finished room above the garage (also with radiant tubes in the floor), and a basement garage below. So in the interest of keeping the room above the garage warmer, I wish we had also put radiant in the main garage.

We, too, have a water supply in the garage. I call it the "dog shower". It's another frivolous thing for some, but so handy in the spring (or even now, when the snow has melted leaving a muddy mess. The dogs can come in through the garage and we use the hand held shower to wash off their feet. DH also used it this winter to wash out the inside of the defrosted freezer that is also in the garage. There is also a "canning pantry" in the garage.

A garage is more than a place to park a car, for us.

We ran all the radiant tubes ourselves, so the cost was minimal. The only place we didn't run it was that suspended garage floor. Still wish we had.

david cary, first let me say that many of us spend much more than 5 minutes a day in our garage. And as far as the "environmental costs", no I don't care. I want my garage to be warm, period.

We built a year ago in northern MN. Our heat source is geothermal (electric) with in-floor PEX tubes that circulate antifreeze-containing water. We put radiant heat into the garage and, like you plan to, keep it at 40-50 degrees. It's a great place to store potatoes, overwinter plants, wash the dog, and keep the cars. It is well insulated. My electricity use (3000 SF house plus garage) has been less than 1500 KW during the coldest month of the year ( at 4 cents per KW). Heating that space makes it a useful extension of our house year-round. The only downside during the winter has been a lot of humidity.

duluthjeff, you say you have a humidity issue? That seems odd to me. In floor radiant shouldn't create any additional moisture.

chad m - the OP said no workshop - just cars and a sink. Nice to know that you care about the Earth. That kind of selfishness is what really makes America great.

chad_m,

The humidity comes from the snowy cars coming in and melting off day after day, night after night. It's one of the issues besides operating cost of a tight, heated garage. The humidity plus road salt equals bad news for your vehicles.

I have the tubes in the floor and have not yet hooked up the heat source for mine and this is one of the concerns I have. There are some humidifiers that work at lower temps, but some just keep a window cracked. This'll make the green police shudder of course.

So you have the cost to heat it, then dehumidify it. In my case gas is free so the heat angle doesn't bother me one bit, but I don't want to rust out my cars so I'll probably bite the bullet on humidification. My garage has a future apartment above it so keeping the garage at 50 degrees would help keep the apartment floor warm. I had a master bedroom and closet over an unheated garage at the last house and the floor temp difference was noticeable.

4 cents per KW

Cheap! We're paying8-9.3¢ per kwh---unless you're Elvira and do household chores in the depths of darkness.

Heating a garage to keep the room above warm is not the most effective solution. Instead, use ccspf. Passive beats active.

david cary, you are right. That is what makes America great. You can hug all the trees you want and I don't have to. I built with energy efficiency to do one thing only, save me money. I even have two floor drains in my garage that tie into the gutter/footer drains, OOOPS! Oh, and when I cleared the trees on my lot I started the brush fires with used motor oil. I don't recycle either. I buy my pop cans and news papers. I also pay for trash pickup. So I have the right to throw what I buy in the trash. So go ahead and be green all you want just don't expect me to.

david cary, you are right. That is what makes America great. You can hug all the trees you want and I don't have to. I built with energy efficiency to do one thing only, save me money. I even have two floor drains in my garage that tie into the gutter/footer drains, OOOPS! Oh, and when I cleared the trees on my lot I started the brush fires with used motor oil. I don't recycle either. I buy my pop cans and news papers. I also pay for trash pickup. So I have the right to throw what I buy in the trash. So go ahead and be green all you want just don't expect me to.

Heatherj:

The rest of our house has air circulating through a heat recovery ventilator. That keeps the humidity in the house reasonably controlled. Obviously, you wouldn't want to (or be allowed to) mix garage air into the mix. When you store a slush-laden car in the heated garage, all the water that melts either runs down the drain, or evaporates to condense on the inside of the exterior wall - especially the window, and doors. It's really only noticable when the outside air temperature is below zero. We also overwinter some plants in the garage, and use it as a place to wash the dogs once in a while.

The 4 cents per KWH we pay is for "dual fuel" power that is interruptible by the power company. We have a backup natural gas-fired tankless water heater that is rarely needed.

Due to engine exhaust in the garage, most building codes prohibit shared air handling systems between living space and vehicle garages.

Heating a garage in Minnesota is an affordable must do. If you have ever had one you wouldn't be without it. Getting into a car at 50�F in the middle of winter is like walking outside in your shorts in summer.

In new construction the installation cost is affordable and operating cost for a garage like yours is 5 dollars a month here in Minneapolis using a NG condensing boiler as a heat source.

Naturally starting your car is no longer an issue.

I do not use glycol in attached garages but some do.

Here is a link that might be useful: Radiant Floor Heating for Garage