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What U-value doors are you fitting?


BotusBuild

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With the build approaching that "closing the holes" stage next year, I would like to ask what U-values for front doors are your suppliers specifying?

 

I'm just trying to gauge whether I am being too demanding, or over-zealous, about what I think should be fitted, and what is a reasonable ask. FYI - we are prepared to spend up to £3,500 on this door

 

Cheers

Stuart

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We hadn't planned to, but we ended up with a flashy, flush aluminium front door from Internorm. I think it's 0.6 or something. It's weird having a front door that's stone cold and condenses / frosts up on the outside but is warm and dry on the inside. Think it was £4k on the schedule including the side light glazing.

 

Edit. Door element is 0.78, sidelight glazing is 0.6. 

Edited by Conor
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I'm going for U value 0.8 outside doors - pricing is bundled so don't have separated costs. Got 2 x Composite ones in 2020 for €4850 for my old house. They have similar U values although it wasn't a requirement for that project. Very solid & warm! 

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28 minutes ago, Kelvin said:

What do you think should be fitted?

I've been "chasing" something with U-value down to 0.8, but from what is being specified, even 1.0 seems are good place to be

 

Conor's 0.6 is immense

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8 minutes ago, BotusBuild said:

I've been "chasing" something with U-value down to 0.8, but from what is being specified, even 1.0 seems are good place to be

 

Conor's 0.6 is immense

When I looked at Internorm they were 0.76. 
 

I’ve been trying to balance the cost of everything with the performance as we all do. Going lower than 1.0 was almost doubling the cost for us which I’ve diverted to triple glazed upstairs rooflights. 

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7 hours ago, BotusBuild said:

I've been "chasing" something with U-value down to 0.8, but from what is being specified, even 1.0 seems are good place to be

 

Conor's 0.6 is immense

According to my schedule the bog standard Rationel Auraplus front door at £1300 has a u-value of 0.59. 

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On 07/12/2022 at 13:26, BotusBuild said:

Mike, what make are you 0.8 outside doors?

 

My last Rationel quote was 0.88 U value, looks like they've improved since. My 0.8 U value on my current house came from Palladio - made in Limerick, Ireland. I got a quote from NorDan this week and they list U value of 0.8 too. It's harder to get better but I've two more quotes due in. I'm sure Internorm are great but I've found them expensive. 

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  • 3 months later...

@Kelvin I know this thread is a few months old but wanted to ask - where did you get you u = 1.0 door? I am struggling to find too many suppliers even in this range. I want to get something better than the 1.4-1.6 that I have seen offered but also not go crazy and spend huge amounts of money.

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Rationel quoted the front door for my house as 0.59 W/m2k too, but I'm not going with Rationel.

The company I'm ordering from (Allan Bros) are supplying an Outline front door with the U-value of 0.72 W/m2k.

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32 minutes ago, SSKK said:

@Kelvin I know this thread is a few months old but wanted to ask - where did you get you u = 1.0 door? I am struggling to find too many suppliers even in this range. I want to get something better than the 1.4-1.6 that I have seen offered but also not go crazy and spend huge amounts of money.


Nordan. No glazing in the door. 

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  • 2 weeks later...

A door is ~ 2m2 in area and you only have a few of them, so a U-value of 0.65 vs 1.0 or whatever is small beer in terms of the contribution to total heat loss.  What is more important IMO is how airtight it is.  If it doesn't seal properly then you will lose far more heat through draft cold air exchange, especially if you are using MVHR. 

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38 minutes ago, TerryE said:

so a U-value of 0.65 vs 1.0 or whatever is small beer in terms of the contribution to total heat loss.  What is more important IMO is how airtight it is

Just what I was thinking.

The fitting of the frame should be easy enough to get airtight. But the door in the hole is a lot harder, and may need adjust every now and again.

 

I fixed my leaky back door last year (ended up a simple fix, the threshold had come loose). Not made a huge difference in the kitchen temperature, or the energy usage, but not having a cold draught on my feet is lovely. 

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1 hour ago, TerryE said:

A door is ~ 2m2 in area and you only have a few of them, so a U-value of 0.65 vs 1.0 or whatever is small beer in terms of the contribution to total heat loss.  What is more important IMO is how airtight it is.  If it doesn't seal properly then you will lose far more heat through draft cold air exchange, especially if you are using MVHR. 


Exactly the conclusion I came to. 

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If a door has a U-Value of 1W/m2.K, the mean temperature difference over the heating season, of 5 months is 14 K, then:

 

1 [W.m-2.K-1] x 14 [ΔT] x 5 [months] x 31 [days in month] x 24 [hours in day] = 52,080 Wh.m-2 or 52 kWh.m-2.

That is about the same as 5 litres of diesel, which if you by it at the highly taxed gas station will cost about £8.

Double it for a 2 m2 door.

 

The U-Value of a door is not the problem.

 

Edited by SteamyTea
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