Replace glass or entire windows?s

fahim01

Hi everyone.

We moved into our home a few years ago which was built circa 1996. We soon realised that the house doesn't retain heat so well in the winter months and one of the reasons for this is the windows which appears to be original to the house. They are wooden frames and (slim) double glasses units although appear in good condition. So my dilemma is whether I should retain the frames and replace the glass with units that are more energy efficient (windows have at best a 10mm rebate) or replace the entire unit with upvc. 
Thanks

ratrace

If heat loss is the only reason you want to replace the windows then i would caluclate what savings i would be making after the new windows have been installed and then work out how many years it would take you to break even for eg:

bills with old windows p/m

bills with new windows p/m

cost of new windows didved by the new savings = X years to break even

Its like a debate i was having with a friend about his new electric car thats costs £25k so he could save £75p/m in fuel without taking into account the break even point buts thats another story for another time.

Just trying to save you your hard earned cash especially in the current times

ytfcmad

Replace the whole window, the frames are poor thermal performers and will fall apart before any replacement DGU's will. 

DorsetLad

Why do you think that the windows are mostly to blame for the heat loss? In most houses the heat loss through the windows is only about 10-20% of the total heat loss, so replacing windows that are already double-glazed (though admittedly not the most efficient type) with more double-glazed windows is not going to reduce heat loss by much, maybe 10%. Have you checked other sources of heat loss: Is your loft insulation up to current standards? Are there draughts from worn draught-excluder strips on the windows and doors, or through gaps in skirting boards or floor boards? If you feel these particular windows are partly to blame, could you fit secondary glazing to them (much cheaper than new double glazing)? 

If I were you I would hesitate to replace 25-year-old double-glazed wood windows, in good condition, with UPVC windows, which may not look as good and which generally have a shorter like expectancy (about 20-25 years) than wood windows (we have just replaced the original wood windows on our house and they've lasted 120 years!). 

FreeBear

ytfcmad said: Replace the whole window, the frames are poor thermal performers and will fall apart before any replacement DGU's will. 

Rubbish. Wood has a very low rate of thermal conductivity. The frames, regardless of the material they are made from, account for very little heat loss once the area of glass has been taken in to account. Further more, a well made timber frame will outlast any uPVC window by a considerable margin (25 years for uPVC, 60 years or more for timber) as long as it is maintained. A timber frame is also a lot easier to repair than a plastic one.

OP - Depending on the thickness of the frames, it may be possible to fit thicker sealed units. You would need to get a window supplier/fitter in to measure up and quote. If you want low cost options to replacing the units, curtains with a decent thermal liner will help during the winter months. Alternatively, secondary glazing on the inside of the frames is another option to consider.

fahim01

Thanks for your responses. 

My preference is to keep the existing frames and I've taken another look today and reckon the windows have a 14mm thick DG unit. As suggested I'll find a supplier who can replace the them, hoping that they can provide the thermal efficiency of new windows. 

Brian_Pamo

I’m not allowed to advertise but if anybody is near Manchester I can suggest a company who do everything.  

shaun_from_Africa

Have you had a good look around the outside of the windows to make sure that there are no gaps present?
As the windows are at least 24 years old, it's possible that the frames may have shrunk or warped a tiny bit or some of the cement/plaster/silicone used may have dropped out.

ytfcmad

FreeBear said:

ytfcmad said: Replace the whole window, the frames are poor thermal performers and will fall apart before any replacement DGU's will. 

Rubbish. Wood has a very low rate of thermal conductivity. The frames, regardless of the material they are made from, account for very little heat loss once the area of glass has been taken in to account. Further more, a well made timber frame will outlast any uPVC window by a considerable margin (25 years for uPVC, 60 years or more for timber) as long as it is maintained. A timber frame is also a lot easier to repair than a plastic one.

OP - Depending on the thickness of the frames, it may be possible to fit thicker sealed units. You would need to get a window supplier/fitter in to measure up and quote. If you want low cost options to replacing the units, curtains with a decent thermal liner will help during the winter months. Alternatively, secondary glazing on the inside of the frames is another option to consider.

Its not rubbish, the overall window will be poor due to age, wood on its own is a good performer thermally, what the OP describes is not the best. 25 years in the trade tells me this  

shaun_from_Africa

ytfcmad said:.

Its not rubbish, the overall window will be poor due to age, wood on its own is a good performer thermally, what the OP describes is not the best. 25 years in the trade tells me this  

But that's not what your earlier post stated. In fact, it was the exact opposite.

ytfcmad said:

Replace the whole window, the frames are poor thermal performers and will fall apart before any replacement DGU's will.

ytfcmad

shaun_from_Africa said:

ytfcmad said:.

Its not rubbish, the overall window will be poor due to age, wood on its own is a good performer thermally, what the OP describes is not the best. 25 years in the trade tells me this  

But that's not what your earlier post stated. In fact, it was the exact opposite.

ytfcmad said:

Replace the whole window, the frames are poor thermal performers and will fall apart before any replacement DGU's will.

Just for you, wood performs well thermally as a raw material, old wooden windows versus whats available today dont. The best thing to do would be to replace the whole window.