Replacement of Crittall Windows in Historic Oak Framed Building

This is an amazing project. Every window and every door used here is at one the highest possible specifications we could provide. Lacuna make the most airtight and thermally efficient bifold doors available. STM Tinium holds the title of our absolute best product in terms of energy efficiency – certification done by independent Danish testing company EnergiVinduer. And we’ve squeezed the best triple glazing unit that we possibly could squeeze into the incredibly thin, thermally-broken Alitherm Heritage. You might actually notice that the Alitherm frame has lost its normal stylistic step in the opening casement – this is because the glass unit wouldn’t fit if that step were in play!

The huge bay window sections used to be the coldest and least airtight parts of the house. The problem here was ultimately the same of a home with stone mullions: not many windows are small enough to fit within these pre-determined structural spaces – that’s why the result is horribly inefficient steel frames. In this situation, our aim was to provide a thermally-competent frame, without using a thicker frame section than the existing units. And we absolutely failed at that; it’s not possible. But we did a pretty good job of tweaking the surrounding structure… This was a lot of work for our installers, but it allowed us to install a far more insulating window with a slightly thicker frame, but without noticeably decreasing the amount of glass area. As a result, our customer didn’t need to compromise on the amount of natural daylight coming into the home.

The frames we used were made with a lip around all the outer frames – a similar idea that’s commonly used in America. When the building allows such a profile, this is an addition that has no choice but to improve the weather-proof qualities of a product.

A Lacuna bifold, as always, is the only bifold we strongly recommend as a first choice. This one isn’t even triple glazed, but will still out-perform a triple glazed aluminium option. Plenty of performance for a renovation!

The internal blinds are not from us, but look very nicely integrated. Be sure to check when you order, but most of our products will have enough space against the glass to install 3rd party blinds just like these.

Internal blinds are also possible to fit up against our windows. These STM Tinium units were ordered with a Basalt Grey (RAL7012) finish internally and a Pebble Grey (RAL7032) finish externally.

Despite parts of this home having tudor style features, this shouldn’t limit the owners to tudor style performance in their windows! By using products that can renovate a traditional home without ruining the classical appearance, we’re able to vastly improve the indoor quality of life for our customers.

Products used:

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