# BER ratings



## gcgcg (19 Aug 2010)

We're getting various quotes for double glazing - one of which is more expensive but A rated (Bonner windows) all the others are B rated but 15-20% cheaper. My question is how do I work out if it is worth paying the extra for A rating? I know the rating is related to the BERC classification and that is based on their U values- so how do U values translate into money saved?
cheers


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## sydthebeat (23 Aug 2010)

gcgcg said:


> so how do U values translate into money saved?
> cheers



in order to find this out an assessment needs to be done on the whole building which includes all the elements in that building.

while the BER software (DEAP) would give an approximate result... DEAP makes many assumptions!!.... the most specific software to use would be the passive house PHPP package. Youd probably be looking at about 1000 to do an assessment with the goal of being able to analyse the results and convert to monetary values...

to be honest A or B ratings on windows doesnt really count for much at all.... who has done the rating??? are they WEP ratings or BFRC rating??? are they tested to EN14351 and BS 6375.....


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## gcgcg (23 Aug 2010)

*energy savings calculator*

Thanks sydthebeat. I also found a UK energy calulator which backs up what you say (on the website of GGF). ( I put in our present set up and then b ratings to see how much I'd save and then repeated for A ratings). And the price saved per year is very small. Even assuming increases in inflation, a very long payback and the extra cost of energy here an A rated window from Bonner looks at bit costly. However, Doyle windows are doing an A rated window which is very competitive...


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## Leo (23 Aug 2010)

But is Doyle's A rating the same as Bonner's???


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## sydthebeat (23 Aug 2010)

Leo said:


> But is Doyle's A rating the same as Bonner's???



exactly my point


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## Leo (24 Aug 2010)

sydthebeat said:


> exactly my point


 
Yep, just thought it was worth restating as it seemed to be missed by the OP's response.


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## Construct (25 Aug 2010)

An important consideration will be the workmanship associated with the actual putting in of the windows. What draughts are coming through now. What steps will be taken to seal around the new windows? I presume they are no vents in them. Will the situation as regards draughts be a lot better when the new windows are in


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## reanster (26 Aug 2010)

*trickle vents*

Hi, i recently had uPVC windows installed in a rented flat. The increased "air tightness" seemed to draw dampness out of the stone walls from GF level up approx 2 feet. This never occurred before. Thinking it might be rising damp we hacked off the render and dug into the floor but everything was bone dry. We left it a few weeks, replastered and installed a trickle vent into the window.

I have 2 questions...1. has anyone had a similar experience and 2. surely trickle vents, whilst improving air circulation, must reduce heat retention

Any advice is appreciated!


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## sydthebeat (29 Aug 2010)

reanster said:


> Hi, i recently had uPVC windows installed in a rented flat. The increased "air tightness" seemed to draw dampness out of the stone walls from GF level up approx 2 feet. This never occurred before. Thinking it might be rising damp we hacked off the render and dug into the floor but everything was bone dry. We left it a few weeks, replastered and installed a trickle vent into the window.
> 
> I have 2 questions...1. has anyone had a similar experience and 2. surely trickle vents, whilst improving air circulation, must reduce heat retention
> 
> Any advice is appreciated!



permanent ventilation is vital for the health purposes of the inhabitants...

if there is no ventilation, then stale moist air is allowed build up and condense of surfaces... this is most likely what has happened...

air tightness does not "draw" moisture into a dwelling, in fact the opposite happens... a warmer, tighter house has a lot more positive pressure pushing outwards through the fabric than a draft cold one... this actually keeps condensed moisture out of a dwelling...

you are required to have permanent, and rapid ventilation as much as you are required to have adequate insulation and energy conservation....


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