Is there really much difference between A and A+ rated double glazing?

Ken2000

I'm looking at getting new double glazing installed and have a quote for double (or triple) glazing. I have a reasonable quote but the windows are only A rated. It's an additional £900 to upgrade all windows to triple glazing.

Should I be looking for A+ windows and should I really consider triple glazing (particularly on the north facing walls)? 

Martin_the_Unjust

What’s the main reason for you getting it, heat or noise insulation?

It always used to be double for heat triple for noise but it’s a bit more complicated now.

tacpot12

I would expect the cost difference to be minimal in the context of the overall cost. If you can afford the difference, I would go with the higher spec. (There is has  to be a measurable difference in heat insulation between A and A+ rated windows, otherwise the rating would be the same.) 

BUFF

https://www.bfrc.org/energy-performance There will be a difference but imo fairly minimal.
& like all of these things there are different qualities of triple glazing (what thickness of unit is being suggested?).
Can the walls take the extra weight of a triple-glazed unit?

The north facing windows aren't likely to benefit from solar gain (which is part of the rating calculation). Check/compare the U values.

coffeehound

If you intend to leave trickle vents open all year round, then it wouldn't be worth the extra for triple glazing

Ken2000

Martin_the_Unjust said:

What’s the main reason for you getting it, heat or noise insulation?

It always used to be double for heat triple for noise but it’s a bit more complicated now.

Thanks for the reply. The main reason for the windows is for heat, as I live in quite a quiet area. 

Ken2000

coffeehound said:

If you intend to leave trickle vents open all year round, then it wouldn't be worth the extra for triple glazing

At the risk of sounding silly, why would I decide to not leave the trickle vents open?

coffeehound

Ken2000 said:

coffeehound said:

If you intend to leave trickle vents open all year round, then it wouldn't be worth the extra for triple glazing

At the risk of sounding silly, why would I decide to not leave the trickle vents open?

I'm in the minority here on this, but based on my own experience find that trickle vents usually cause too much ventilation, with too much heat loss (and let too much outside noise in, to boot).  

It's not helped by the fact that typically every replacement window will be fitted with one or more vent.  Since they often leak even when closed, that can cause a draught in itself, let alone when they are opened.  IMO, if they are present and in use, they will render it pointless to spend more on triple glazing, from both the thermal and acoustic points of view

Effician

coffeehound said:

Ken2000 said:

coffeehound said:

If you intend to leave trickle vents open all year round, then it wouldn't be worth the extra for triple glazing

At the risk of sounding silly, why would I decide to not leave the trickle vents open?

I'm in the minority here on this, but based on my own experience find that trickle vents usually cause too much ventilation, with too much heat loss (and let too much outside noise in, to boot).  

It's not helped by the fact that typically every replacement window will be fitted with one or more vent.  Since they often leak even when closed, that can cause a draught in itself, let alone when they are opened.  IMO, if they are present and in use, they will render it pointless to spend more on triple glazing, from both the thermal and acoustic points of view

Totally agree coffeehound.

Since blocking the trickle vents on our windows the house is warmer whilst using less energy & suffers much less from outside noise . Condensation has also been less of an issue than in the past but due to the way we heat our home this may not be a universal benefit .

.

greenface2

Soon trickle vents will be in every new window regardless of like for like or new build . They are becoming compulsory . Why change your draughty windows for draughty new ones . I can see big customer complaints due soon . Throws all trickle vented windows into C rated windows . They have a big hole ripped through them.   

FreeBear

greenface2 said: Soon trickle vents will be in every new window regardless of like for like or new build . They are becoming compulsory . Why change your draughty windows for draughty new ones . I can see big customer complaints due soon . Throws all trickle vented windows into C rated windows . They have a big hole ripped through them.   

Whilst current regulations require trickle vents if the old windows had them, I really hope it doesn't become the default on all replacement windows. I don't see the point in fitting a window, sealing up the edges to stop draughts, then punch a ruddy great hole through the frame.... There are better ways of ventilating a property - That is why most windows have hinges & handles.