Whether you’re after wide opening spaces, unobstructed views, or a stylish and functional servery window, our aluminium bi fold windows have got you covered. Secure, versatile and chic, they feature all the bells and whistles you need. Sometimes referred to as ‘concertina windows’ or ‘folding windows’ bi fold windows fully maximise openings, setting them apart from other windows that only slide open halfway or swing open to a fixed degree.