Anglian Rated B Windows vs Local Firm Rated A

PeggyAnn_2

Some very useful info here. Thanks guys!

We're renovating and extending a cottage but we're on a very tight budget. Our builder, who's a friend and supplying materials at cost, gets very good discounts from Magnet, so our first inclination is to go for them for the windows. However we'd appreciate some advice.

Magnet's standard double-glazed timber windows (we have to have timber) are C rated with a U value of 1.7 and a solar factor of 0.45.

For health reasons I need to keep cool in summer and so this will have a bearing on what windows we choose.

However we've no idea whether 0.45 is a good or poor figure for keeping cool or how it compares with other suppliers.

Can anyone help here please?