Target U-values… Cost/benefit sense check… What am I missing? 🤷🏻‍♂️

[Tony L]

1 hour ago, Iceverge said:

 

From my understanding the applied fools don't last as long. Ligter colours suffer less thermal exoasuand contraction too. 

 

This must be why Veka's T&Cs say, "In the absence of any express warranty to be specified by the Seller in respect of Goods which are not “white PVC -U profile” no warranty shall be given in respect of the Goods.".

 

If you want a warranty for a colour, you have to ask them for one, & I don't suppose it's going to be 10 years, which is what they're offering for the white PVC-U.

[Crofter]

On 16/02/2026 at 17:18, fatgus said:

A while ago we looked at the Aluplast's Neo range, but at that time it wasn't commercially available. Might be worth another look. 

We've just taken delivery of a Neo sliding door. It was absolutely unbeatable for u value (0.74 uW) and was considerably cheaper than any aluclad iron. 

Haven't installed it yet but the quality looks good. Mine are dark grey on the outside, and as far as I can tell this is a solid colour rather than a foil wrap. 

I also took the option of having the glazing units delivered separately, which has made handling much easier. It will also allow me to install the frames by screwing straight through the frame. The glazed units were delivered in robust transport frames, unlike the cheaper units I bought from Modern UPVC Glazing.

 

All in all, I'm quite impressed so far.

[fatgus]

9 hours ago, Crofter said:

We've just taken delivery of a Neo sliding door. It was absolutely unbeatable for u value (0.74 uW) and was considerably cheaper than any aluclad iron. 

Haven't installed it yet but the quality looks good. Mine are dark grey on the outside, and as far as I can tell this is a solid colour rather than a foil wrap. 

I also took the option of having the glazing units delivered separately, which has made handling much easier. It will also allow me to install the frames by screwing straight through the frame. The glazed units were delivered in robust transport frames, unlike the cheaper units I bought from Modern UPVC Glazing.

 

All in all, I'm quite impressed so far.

 

Thanks @Crofter

 

That sounds very promising... I'm going to see whether I can visit their showroom this week 👍👍

[TerryE]

@fatgus I agree with your overall assertion that your design choices should be informed by through-life cost benefit trade-offs.  You need to granularise to make doing this practice e.g. Wall U-value 2 vs 1.5 vs 1.2, etc. Also recognise that as-built might well vary from the design calcs due to mistakes in the design or construction quality issues: missing or sloppily fitted insulation, major leaks or missed thermal bridges. For example, our house works pretty much as design except that our slab losses are maybe 30-40% higher as build from a detail that caused edge bridging.   So your heating / cooling system needs to have enough margin to cope with likely variations.

 

Also remember that your heating / cooling system must be capable of adding / removing heat as needed.  For example, we have a 3 storey house with only ground-floor in-slab UFH: no wall mounted rads and pipework anywhere; no heating on the top 2 floors. That is huge initial and ongoing cost-avoidance.  See my blog for details.

Edited 2 hours ago by TerryE