Choosing a front door

[Zebra]

Can anyone help? I have two external doors to buy. Both are in the newly rebuilt front extension, so not in the old part of the house, but I still want a traditional look, but I have also done an enormous amount of work to improve the thermal efficiency and insulation in the house, so don't want the external doors to be a real weak point in this regard.
Looking at new doors from builders merchants, they are either "hardwood" doors which I assume is the imported idigbo or sapele wood which it is not recomended to use for ethical reasons; or they have a very poor U-value if they are softwood. The "economy oak" range seems the best thermally but still only a U-value of 2.7 which is much worse than my windows which have a U-value of 1.6.
I have talked to my joiner about making external doors for me in the same Douglas Fir that he made my windows in, thicker than the standard door to take 24mm double glazed units, but this is working out a bit expensive.
I could get the slim double glazed units, and install them either in a reclaimed door, an off-the-shelf door, or have my joiner make them.
And then there's the style. I would like as much glass as possible to let in light because there aren't many windows in the house. I was thinking stable doors perhaps, with 9 panes on the top, so I could open the top half in the summer, but I don't know if this is a modern fashion and not very traditional at all. I presume anything with that much glass in is not very traditional?
Sorry for the ramble. I was wondering what choices others might have made?

 

[88v8]

Ummmm, I would always choose what looks best.
If I wanted thermal efficiency I wouldn't be living in an old house.

Yours unhelpfully,

Ivor

 

[tobydog]

Zebra - does this help? There are a few older styles with thermal properties. We have a similar problem with our front and rear panel doors that look thinner than those of the chicken house!.

http://www.doorsofdistinction.co.uk/index.ext6.th.oak.html

 

[agbagb]

It's a quandry for sure especially after all the wall insulating youv'e done. Maybe someone could work out the maths, looking at U value 2.7 compared to what a more expensive option DG option might be, then working out the differance in heat loss for the area of the door. Good draught proofing and a heavy door curtain might make a much bigger differance.
You could always think of it as controlled "weak point", somewhere to attract condensation or even to allow ventilation. It's something all well insulated, sealed houses need somewhere unless they have forced ventilation (even with a heat exchanger they are still a heatwise weak point).

 

[plasticpigeon]

buy a reclaimed door, and be happy that no new energy has gone into making it!

 

[JoceAndChris]

Glass was certainly used extensively from the 18th C onwards - I presume it had got a bit cheaper by then as my 18th C porch is half glass - sure you'll have seen the pics I've put up before. Arch topped double doors, wooden diamond shaped glazing bars - so glass to waist height. Same for the windows around.

However, as your house, on the exterior, is really characterised by being a mixture of things, that in fact is very of 2012, I see no real reason why a zebra can't have her stable door, though there's nothing authentic about them for human dwellings.

My friend lives in a converted 19th C workhouse - again another challenging style as you can hardly decorate with a dozen low dirty beds and woodshavings on the floor. The building is broken into flats and housettes, she put a stable door on and it all looks extremely smart and modern and attractive.

 

[AMc]

If you can afford it, bite the bullet and get an efficient door that you like the look of. Make sure they pay attention to draught seals and use timber that doesn't twist after its hung (a problem in my refurbished period door).
If you can't afford it, buy something cheap enough to replace when it gets to you. If you don't fit a door you like, every time you open it, it will remind you of the shortcut and speaking from experience that will bother you more as time goes on, not less until you eventually get the one you should have bought to begin with.

As it's a new door, choose a design that fits with your house and suits your taste - then you're adding a new, "original" feature

 

[LadyArowana]

To me the front door is the face of your house and needs to be something you love to look at when you come home, definately worth spending a bit more to have the one you like. It would seem very appropriate for a zebra to have a stable door

 

[Owain]

A door won't make much difference to overall thermal performance of an extension, especially if it's well fitted with draught excluders.

Can you have a nice thick period curtain inside for extra insulation on cold dark winter evenings?

 

[JohnB]

A door won't make much difference to overall thermal performance of an extension

I can assure you that a door makes a big difference. When I moved in, half of my house had a big hole where the door should be, and fitting a door made a huge difference :lol:

 

[middi]

First and foremost a suitable " front door" for an " old" cottage is determined by two factors:- 1) the age of the building, 2) neighbouring dwellings of similar age and character.
As mentioned on OP, the main thing to worry about is an efficient draught proof seal and stable wood construction. If the door is well constructed there is no need to worry too much about it's thermal efficiency or double glazing as the surface is not that great therefore not conductive to great heat loss. ( although a 1 foot thick door with quadruple glazing is much better than a simple one and a half inch thick wooden door with a thin piece of glass)

Middi

 

[MdB]

In my thermal calcs, I used a U value of 3.54 for the doors. This gave a heat loss figure of 6% of the value for the total insulated house. It would be nice to better than that but it isn't going to make a great deal of difference to the overall figure.

More important is condensation. With a well insulated house and poorly insulated glass in the doors you will have a lot of warm damp air in the house available to hit the cool glass. This is a recipe for condensation. For this reason alone, I would try and get DG units in your doors. Having said that, we have SG in our front door....

 

[Flyfisher]

Here's a replacement rear door we had made. It's a copy of the previous door, except we had it made as a stable door and the glazing is DG. Might be helpful in formulating any ideas.

 

[Zebra]

Thank you Tobydog for that link, that will take me a while to go through and digest. Good that they put the U-value beside each door!
Ivor, thermal efficiency and old houses can be bedfellows! Or so I am hoping! There wasn't much original material left in mine anyway so have had no hesitation in incorporating much thermal improvement! At least I don't want the front door then to be a weak point!
I'm hearing a few votes for performance and personal taste over authenticity here - AMC, JoceandChris.
Lady A, I've moved the front door to the side of the house, you can't see it from the street, so I'll appreciate its performance more from the inside than its appearance from the outside.
Middi, what you're saying seems to me the nub of the argument - the brochures for the off-the-peg doors give a -U-value of around 2.7 (the more glass the lower the performance) which is not that good but they seem to be saying "Oh well it's not that big an area, it won't make that much difference!" It seems to me, why would you allow such a weak point in your insulation?! Or am I fussing too much?
Flyfisher, how thick are those doors, the standard 45mm?

 

[worms]

I know they wouldn't have thought about U-values, but I was impressed by a door I saw on a former barracks building in an exposed site a few years ago, where the construction was two layers of inch-thick, tongued and grooved pine, counterboarded with a thick, wool, army blanket sandwiched between the two.

I always fancied copying that when I get round to replacing the (doubtless-expensive-but-out-of-character) mock Georgian front door on our cottage.

 

[Flyfisher]

Flyfisher, how thick are those doors, the standard 45mm?

A little larger at 48mm.

 

[Zebra]

I know they wouldn't have thought about U-values, but I was impressed by a door I saw on a former barracks building in an exposed site a few years ago, where the construction was two layers of inch-thick, tongued and grooved pine, counterboarded with a thick, wool, army blanket sandwiched between the two.
I always fancied copying that when I get round to replacing the (doubtless-expensive-but-out-of-character) mock Georgian front door on our cottage.

Well actually in the short term I was thinking of making a door out of sheets of ply with some celotex sandwiched in the middle. I'm sur it would be thermally better than anything available!

A little larger at 48mm.

With what thickness panes, if you don't mind me asking.?

 

[JoceAndChris]

Good on you for thinking to make it as cosy as possible with the actual construction. A really thick curtain above, which can be positioned on a portiere rod on the door if side space for stackback is limited, also makes a world of difference. I've put very heavy interlined curtains on both sets of draughty double doors and it's warmed up the house considerably.

 

[Flyfisher]

A little larger at 48mm.

With what thickness panes, if you don't mind me asking.?

I don't mind at all. The DG units are 4:12:4, a total of 20mm.

 

[Zebra]

Been looking for a door again. I can't find anything along these lines second hand, but the one I like best is actually a cheap softwood one.....
http://www.wickes.co.uk/invt/221924