A client appeal that I lodged was allowed in respect of a grade II listed house in Tansor, North Northamptonshire on 24.11.21. It was proposed to replace five windows including installation of slimline D/G units. The existing windows were themselves modern replacements and in a poor state of repair.

The Planning Inspector referenced the HE advice document Traditional Windows, which says replacement windows including adding of D/G is acceptable, provided the design ” follows historic patterns”, and where the glass itself is not historic “it may be possible to introduce slim-profile D/G without harming the significance of the LB.” He considered that the required increase in depth of the timber elements required to accommodate the D/G was not a problem, provided the existing 18mm glazing bar width was retained/replicated.

I feel that this decision gives the lie to council conservation officers who appear to believe that there is an in-principle objection to any D/G on an LB, whatever the circumstances. No one is suggesting that genuinely historic fenestration can be double-glazed, but the above official advice on already replaced windows was clearly being ignored in this case.