What do the energy rating labels mean in real life?

E.g How does A and A+ relate what is installed in passive homes?

Looking at the energysavingtrust website, there seems to be very little different in heating costs with a C rated window and an A rated window. So is it worth going for better then C rated?

(I am looking at UPVC windows for a refit on the rental property where I will be paying the bills, as it will be an HMO. The windows must be UPVC, as that is what tenants demand. )

Remember that a “bad” property gets the tenants it deserves! Better tenants pay higher rents and most importantly give landlords less problems.

Tenants have learned over the years, that if a property does not have UPVC windows, then the landlord is unlikely to have spent money on a good heating systems etc. So a lot of tenants will not even view a property if the windows are not UPVC.

After a few years the factory-finished timber do look like timber, but UPVC sill look like UPVC.

Some of the windows will also be 4 stories up, so making repainting VERY costly.

ringi,

BFRC 'energy rating' labels are a con, IMO.
Designed to make consumers think they are getting the best available....
Ask for Uw-values. Aim for 1.4 as a maximum:
4 - 20 - 4, warm-edge spacer, Low-E coated, Ar. fill, thermal sleeved/broken frames

If you are paying the bills, how long are you paying the bills for?

Actually If you look at a BFRC rating, you'll note at the bottom, the U-window and solar factor (g-value) and effective air leakage are all included.

there's an uncompleted sample on the front page of their website http://www.bfrc.org/#

But yes, the A rating etc by itself isn't so helpful, other than in general terms.

Look for a low U-window, combined with a high g-value combination for best results for energy efficiency (but check that the solar gain won't be an issue in the summer).

U-window is the thing (although the value quoted would be for the standard window size and actual window U-values for each sized window can be calculated, most people just go with the standardised).

Too many companies just give the centre pane U-value of glazing.

Posted By: ringiWhat do the energy rating labels mean in real life?

E.g How does A and A+ relate what is installed in passive homes?

The BFRC scheme is a nominal (and simplistic) measurement of energy loss/gain. It was designed for retail customers who wouldn’t have a clue what a u-value is and were thus at the mercy of sales reps (who themselves generally knew SFO about u-values). A, B, C, etc is much easier to understand and less intimidating then trying to discuss unit heat loss rate.... with Mr & Mrs Bloggs as they are being pressured into signing up for maintenace free, last-a-lifetime replacement windows.
Clearly the same A-rated window is going to have a completely different thermal performance on a north facing elevation then a south facing elevation. As pointed out previously, high solar factor glazing which is being used as a ‘cheap’ route to the A rating is resulting in some serious overheating with large south facing windows.
In my opinion the energy rating of the window is a relatively minor factor when it comes to choosing windows. The u-value and physical durability would be far more important – and weather performance if in an exposed location.

The vast majority of A rated windows would be useless for a passive level dwelling.

I have never seen the point of coloured UPVC, as they age much worse than white. If someone wants brown windows, they should use wood or aluminium.

As to A rated windows giving problems with large south facing windows and solar gain, the window size in the given property are if anything too small so I wish to let in lots of light.