Imitation-Steel Windows in Knutsford, Cheshire

Compared to most of our projects on display, this home is a far more modern affair. The incredibly smooth finished clean lines of the white render, pristine slate roof and Wienerberger Terca bricks are all a far cry (and a welcome change!) from our local Cotswold stone creations.

In part, we were able to use our New York loft style window set up from Unik Funkis in Denmark: thin black frames, very thin decorative bars and satin steel handles. This really shows off the flexibility of the aluminium-clad timber system, as the number of visual choices available can transform the product to suit almost any style of building.

This steel-look window system rewrites the books by delivering exceptional energy efficiency alongside the slimline steel appearance: two qualities never found together! The main “trick” is having a real wooden frame on the inside which is warm to the touch and airtight. Even thermally broken steel systems cannot deliver performance close to this Danish solution.

Installing into render and installing into stonework are different beasts, but black weatherproofing tape will seal everything. Yes, it only comes in black. With these black windows, you can barely see the line. Equally, the shadow gap surround that the black tape creates around a lighter coloured frame suits a variety of situations.

A fantastic example of Unik Funkis’s speciality: an inward opening window door. Minimising sitelines via their New York style glazing bars creates a contemporary version of a classic Juliet balcony. Most factories only have the ability to make outward opening window doors, because it is naturally more difficult to create inward-opening items with a high level of airtightness. Like most unique Unik offerings, these are only available with triple glazing, so we gain a little extra insulation for this one room.

For those wondering about the triple-glazing-only decision: Danish homes do not use double glazing any more, so a Danish company is always going to prioritise the triple glazing requirement for newer innovations.

Clearly, the statement piece here is the large glass-to-glass corner window. The glass joint is only 35mm at its most visible angle: far smaller than even our thinnest purely aluminium only corner we have, and fantastic for a near uninterrupted view over the back garden and greenery beyond.

Also, this is a perfect example of how to utilise plasterlines to create the illusion of a frameless window. Due to the glass being sealed in place from the outside, plastering right up in line with the internal frame doesn’t block anything important. Ask your plasterer for that detail, and you’ll create a frameless window look from the inside, whilst still having a proper high performance frame.

Internally, the black window frames give a strong contrast to the lighter interior. Being only 19mm, the glazing bars achieve the clients’ design choices, without reducing the incoming light too greatly. We’re quietly confident these are the slimmest possible glazing bars available in the UK… Jet Black RAL9005 is standard colour for most factories in a lot of industries, so this is generally an easy colour to match and work with.

To ensure a consistent and long lasting weather seal, we use a German expanding tape between the outer edge of a window and the wall. Conforming to the shape of the wall, even with rough surfaces, this is the key barrier to stop driving rain away from the main airtight layer of expanded foam. Add the butyl airtight rubber seals in the windows themselves – not impregnated with oil and therefore won’t shrink over time – and add the extra weather seal around the outside of the casements, and the resulting installation far surpassess any normal UK home’s windows and doors.

For further customisation, Scandinavian hinges always stand out on darker coloured frames. Satin steel, galvanised steel and mid-grey powdercoats are always standard hinge options from factories – it’s simply the convention and tradition that’s been in place for decades. Some factories, like Unik Funkis, recognise that’s not to everyone’s taste and offer their hinges in any colour that’s needed to suit the frames.