12 year old upvc glass units to upgrade

[kevhky]

Hi

Im looking to upgrade my 12 year glass units to new energy efficient glass

I have been looking at Pilkington K glass but not sure if there is any others out there

Ive done a bit googling and the pilkington came up everytime

Im only planning on changing the glass in my bay window as in winter you can really feel the cold, it is a 4 frame window approx 1ft x 5ft x 4 frames which all do go down to ground level

Anyone advice would be great as in savings and suppliers

Thanks in advance

Kev