Sliding sash style upvc

[Oz07]

Are there any decent makes of sash windows in upvc with good u values? All that I've seen look too chunky. I would wonder how good the window performs with seals as well not having as much compression?

Edited April 9 by Oz07

[Mr Punter]

I have used the "Rose" range in a couple of properties.  They are pretty good lookilikies for trad timber.

[Oz07]

Yeh just had a look. They seem good. Thin bars, butt joints etc. 1.2 u value as well. What's the pricing like compared to timber?

[Mr Punter]

I think similar or more expensive, depending on the range.  Roseview are based on standard upvc profiles from Rehau and do lots of extra customisation and finishing.  Their top range is almost indistinguishable from timber.

[Iceverge]

Sliding sash looks pretty but is the draftiest window you can buy. 

 

I was in a new build of some neighbors, 0.15 walls floor and roof, compact foot print, wet plaster and plenty of airtight tape and MVHR. 

 

And sliding sash windows........

 

You could feel the cold breeze on the back of your neck sitting in the kitchen. 

[Oz07]

5 hours ago, Iceverge said:

Sliding sash looks pretty but is the draftiest window you can buy. 

 

I was in a new build of some neighbors, 0.15 walls floor and roof, compact foot print, wet plaster and plenty of airtight tape and MVHR. 

 

And sliding sash windows........

 

You could feel the cold breeze on the back of your neck sitting in the kitchen. 

Its unfortunate isn't it because they're a good window to have in summer can get some natural convection going. 

[Iceverge]

Tilt and turn baby. 

 

Tilt and turn! 

 

 

[craig]

They're a practical window, easy to slide up and down but they are far from being "decent" - just the nature of sash and case.

[ab12]

On 10/04/2026 at 12:50, Iceverge said:

Sliding sash looks pretty but is the draftiest window you can buy. 

 

I was in a new build of some neighbors, 0.15 walls floor and roof, compact foot print, wet plaster and plenty of airtight tape and MVHR. 

 

And sliding sash windows........

 

You could feel the cold breeze on the back of your neck sitting in the kitchen. 

OMG are we talking modern DG PVC sliding sashes?

Kind of expect old single glazed timber sliding sashes to be draughty but not the current DG PVC types. 

Is it down to poor craftmanship? quality of profile?

I was thinking of getting PVC sashes but this........the fact yoiu mentione they're draughty...... has kind of dented my confidence

[Iceverge]

It's the seals. Brush and sliding seals just don't work anywhere as well as compression seals.