Good window article.

We designed our house about 15 years ago and word on the street at the time was good low E Argon filled double with warm edge is as far as makes sense to go. When I worked at CAT early 80s we were debating whether double was worth it!! Now I really wish we had gone triple with PH installation details (minimised thermal bridge) – not for the energy savings (sod all) but for the comfort and complete absence of condensation.

As our home needs so little heat it can be at 20C on a frosty morning with only the heat from the night before. Under these conditions the bottom of the glazing hits dew point and we get a bead of condensation. Not a big deal but annoys me.

If you really get into windows then AECB forum has some great expertise including people who have used advanced Canadian as well as best of European. Trying to reduce frame heat loss (surprisingly significant) without resorting to composites of wood an PU foam is a bit of a mission for some of us. Certainly possible to use non PH windows in a PH if you do the sums and optimise pane size and installation details. AECB forum regular Mark Siddall presented a paper at PH conf a couple of years ago on appropriate U values for UK to achieve comfort. (He did a great one on wind tightness this year if you have not seen it, again available via AECB forum!!).

There managed not to rant about Zero Carbon