Posted By Lbear on 02 Apr 2013 03:25 AM



GBA Article on Insulated Doors

Best option is to look to Europe or even Canada for an answer. Intus makes really well designed and affordable entry doors. Mult-locking mechanism and double/triple gaskets.

Best option as defined how?  If you pay 2X, 3X, or more for a door, you will never recoup that cost in energy savings.  Martin at GBA says essentially the same thing when discussing the addition of a mud room.

Posted By arkie6 on 02 Apr 2013 05:45 AM

Best option as defined how?  If you pay 2X, 3X, or more for a door, you will never recoup that cost in energy savings.  Martin at GBA says essentially the same thing when discussing the addition of a mud room.

All depends what your goals are. It was discussed on GBA that deep energy retrofit's on average take over 100 years to see a ROI. Yet people still do them.

People spend on average $40k to remodel a kitchen. People spend $2k on a big screen TV. The list goes on and on...

A well built European entry door from Intus will cost you around $2k. A cheap HD door that will leak air and be a big energy hole in your thermal envelope will cost you $800.

If everything is viewed through the eye of ROI, in the end it makes no financial sense to build new, might as well buy something already built. Why buy the $40k car when you can get the $20k car and vehicles are depreciating assets anyways?

I am not saying that there is no place for reviewing the cost of something and the added benefit of said product. My point is that if you are looking to save $1k by getting a cheap door and have a 3x8 leaky hole in your wall, it really doesn't make sense in the grand scheme of things. We waste A LOT of money on totally stupid stuff all the time in our daily lives. When it comes to building green and sustainability for future generations, spending a little more on a quality door is money well spent.

Why must everything be one extreme or the other? Is there no middle ground?

Does Intus even make an insulated fiberglass entry door? I looked at their website and did not see anything like that offered. They offer wood entry doors, but as has been discussed extensively here GBT, a few inches of solid wood is a pretty poor insulator. A hardwood that is typically used for doors will generally have less than R1 per inch. For a typical door thickness, you are looking at less than R3.  For a polyurethane foam insulated fiberglass door such ThermaTru, the published R value for the door panel is over R7.

Posted By arkie6 on 02 Apr 2013 05:18 PM
Why must everything be one extreme or the other? Is there no middle ground?

Does Intus even make an insulated fiberglass entry door? I looked at their website and did not see anything like that offered. They offer wood entry doors, but as has been discussed extensively here GBT, a few inches of solid wood is a pretty poor insulator. A hardwood that is typically used for doors will generally have less than R1 per inch. For a typical door thickness, you are looking at less than R3.  For a polyurethane foam insulated fiberglass door such ThermaTru, the published R value for the door panel is over R7.

Intus does not make fiberglass but it does make door designs that get R5-R7. I was merely offering them as a low cost option. They achieve Passive House sealing standards.

The ThermaTrue door hardware and sealing design are not up to par for good air sealing. I read where some people tried to modify the door by installing multiple locking mechanisms with an attempt to pull the door tighter. Most people are not up to re-engineering doors.

I would be curious to see some studies on ThermaTru doors and their sealing capabilities. 

Therma True will sell you a door with multi point locks installed -it adds a few hundred dollars and they are quite a bit tighter than the standard TT door. Doesn't solve all the issues but it is a step up.

Posted By Bob I on 03 Apr 2013 08:25 AM
Therma True will sell you a door with multi point locks installed -it adds a few hundred dollars and they are quite a bit tighter than the standard TT door. Doesn't solve all the issues but it is a step up.

With the multi-lock, what is the price range of that thing? $1,500+ ?

Even with the multi-lock, I would seriously doubt that TT is considered an air tight door.

It all comes down to style. 95% of people don't care or even know to care what R-Value a door is and how well it seals. It's all about looks & price, and TT caters to that crowd. So what if your door is R1 and leaks enough air that it does 5 air changes per hour? As long as it looks good and is priced cheap.

A German made door is a totally different class of door. When you pay 30 cents per kWh you begin to pay attention to what R-Value your door is and how well it keeps the air out.

Hopefully TT steps up to the plate and engineers a door that is worthy of Passive House standards but I won't be holding my breath.

People living in scorpion country do appreciate an air tight door. Nothing like walking around and getting stung by a scorpion will make you wish you had better sealing doors.

costs seem to be $600 & up. I think the lock system adds about $250. No, its not an airtight door but it's much better than the standard. I'm sure it's not as good as the German doors; what do they run?

Posted By Bob I on 04 Apr 2013 08:37 AM
costs seem to be $600 & up. I think the lock system adds about $250. No, its not an airtight door but it's much better than the standard. I'm sure it's not as good as the German doors; what do they run?

The lowest priced I found is an Intus entry door, which will run you around $1,800 for a 42"x 90" door. This is with triple pane glass, all three panes tempered, 3-point locking system with latches, double gasket seals. The door frame gets a U-Value of 0.14 and the glazing is a U-Value of 0.10, so you are looking at around a R-8/R-9 total.

The prices go up from there. Typically around $2k-3k depending on who you go with, prices can really jump to $4k-$5k if you go custom made and high end German or Polish made (but German design based) doors.

It's not cheap but as mentioned if consumers don't demand better made doors (and windows), then the US market will continue to make what it makes. I would rather get a high quality entry door and spend the $2k and cut back on the overpriced kitchen granite counter tops. I can find granite tops pretty inexpensive if you shop around the granite warehouses. They are usually 1/3 of the cost of HD Lowe's or some kitchen/bathroom counter store.

Buy a flush steel insulated door with multi-point hardware. Add 3/4" wood to exterior recessed on two sides and top.
Add second door stop and weatherstriping that wood closes against.
Add 3/4" wood to interior that is larger than flush steel slab on one side, top and bottom (not hinge side).
You now have an affordable, insulated, custom, triple weather striped, multi-point locking door.
Now your biggest problem is finding door hardware.