How a box sash window is actually built

You can tell a lot about a sash window from one photo of the box.

The cord runs over the pulley and down the stile to the weight. The parting bead has to sit clean, because that is the surface the sash slides against for the next fifty years. The weights are matched to the sash, not to a table: get that wrong and the window either drops or will not stay up.

None of this is visible once the window is in. That is exactly why it is where corners get cut.

The order of work matters more than the parts. We finish the paint system before the glass goes in, not after. Paint applied around installed glazing leaves brush marks on the bead, and the customer sees them in year two when the light hits the reveal at the wrong angle. It is not a defect you can argue with, because the customer is right.

We make our windows in Lithuania, to our own drawings and specification, and they arrive wrapped, labelled per opening and ready to fit. We supply trade only and never install, so the fitter on site is never competing with us.