The History of the Rising Sash Window
The origins of the rising sash window are obscure. Most commentators place its origin in the eighteenth and nineteenth centuries, but there is good evidence to place it rather earlier. Carol Davidson Cragoe, in "How to Read Buildings" (Herbert Press, London) suggests the invention might be attributed to Robert Hooke (1635-1703). There is certainly a good case to be made (of which, more anon) and he was certainly an inventive and creative mechanic, engineer, designer, and architect with the capability of doing so. As curator of the Royal Society and, simultaneously, laboratory technician to the eminent physicist Robert Boyle, he demonstrated a prodigious ability to design and build mechanical and scientific apparatus of all sorts. He later became an assistant to the great architect Christopher Wren, and, as Chief Surveyor to the City of London, was responsible for overseeing more than 50% of the rebuilding of London following the Great Fire of 1666.
An architect in his own right, few of his buildings survive today, but a drawing in 1858 of his Royal College of Physicians (completed 1678) shows rising sashes in every visible elevation.
Wikipedia quotes Ham House as an early example, but this house dates from 1610, and has been extensively refurbished by successive owners over the centuries. Whether the windows are originals or not is conjectural, but to me, it seems unlikely that they could all have survived as well as they have from that early date. I look forward to being corrected by others, on this point.
A very early reference to sash windows appears in a diary entry of Robert Hooke's dated Feb 2nd 1680 (http://www.roberthooke.org.uk/batten6.htm)
This is the earliest known reference to sash windows, although sliders of one sort or another have been with us since the dawn of time. Unglazed openings were shuttered with wood boards, and a sliding version survives to the present day as the horizontal Yorkshire Slider. As glass became available, solid boards were simply replaced with frames, and further improved over time: Simple, economical, and uncomplicated.
The invention of the rising sash will almost certainly have been prompted by the fashion among the wealthy for Palladian-style buildings where window openings are taller than they are wide. This style was introduced in the late sixteenth century but was not widely adopted. It became fashionable in the late seventeenth century, during Robert Hooke's lifetime. But whether he, or some unknown but enterprising joiner, conceived the idea of counter-balancing the sashes with weights concealed in cased boxes, we may never know. The story is further confused by the fashion, from time to time, to give houses complete make-overs, throwing out the old and replacing with new. (So what's changed?)
There are clues, though, when dating a particular window, as styles and construction techniques changed over the years. This is not an exact science, however, as alterations, copies and even the possibility of downright fakes all have to be taken into consideration.
In general terms, the early sash windows were constructed with solid, plain glazing bars, perhaps relieved by a slight bevel, glazed with hand-made 'cylinder' glass. It is these imperfect panes, with their inevitable undulations, pits, and reams, which give old windows a sparkle when seen from afar as the light is caught and scattered.
Initially the window frames were generally inserted directly into the structural opening to leave the cased box completely visible from outside. This feature on its own is not a sure sign of antiquity, as an old-ish window may be inserted in a new-ish building in just the same way. However, the cased box hiding the weights is a bulky item and it must have soon occurred to a builder that concealing the box in a rebate built into inside face of the (solid) brick or stone wall would greatly increase the amount of light for a given structural opening (and, also, solar gain on a sunny winter's day in an era without central heating).
Over the years, architects and their joiners competed to improve their designs over those of the neighbours. Frames became lighter, and glazing bars became elegantly moulded and ever slimmer, culminating in the slender lambs-tongue profile which is the ultimate development of the ovolo mould. (Many modern replacements, of course, can be instantly spotted from the far side of the room by the rounded moulding at the junctions, where the ovolo was applied by a power-router after the frame was assembled. Ugh!)
As technology produced ever-larger panes of glass, glazing bars became fewer in number, (except where they were used for purely decorative purposes) shown by the proliferation of Victorian houses with but a single vertical glazing bar. By the turn of the century glass was available in large rolled or drawn sheets, and many elegant sash windows of the early 1900s have no glazing bars at all, relying on delightful proportion for their merit, and decoration, if any, being provided by arches and curves in the main structural components. The chief driver of this process being, as always, first-cost, bringing a fine product to the mass market.
The aim of the designer is generally to achieve the most pleasing balance of proportion and economy. Ostentatious display may be recognised in the inappropriate proliferation of glazing-bars and arched rails used simply to demonstrate the wealth of the client. Wherever you look, you should be able to recognise these features. In general, the rising sash window forms a major part of our British architectural heritage, and deserves every effort to preserve and improve it for the benefit of future generations.
Useful links:
www.supasash.com
www.rugbysash.co.uk
http://forum.expertexpert.com
www.roberthooke.org.uk
Copyright KJN 2011
The origins of the rising sash window are obscure. Most commentators place its origin in the eighteenth and nineteenth centuries, but there is good evidence to place it rather earlier. Carol Davidson Cragoe, in "How to Read Buildings" (Herbert Press, London) suggests the invention might be attributed to Robert Hooke (1635-1703). There is certainly a good case to be made (of which, more anon) and he was certainly an inventive and creative mechanic, engineer, designer, and architect with the capability of doing so. As curator of the Royal Society and, simultaneously, laboratory technician to the eminent physicist Robert Boyle, he demonstrated a prodigious ability to design and build mechanical and scientific apparatus of all sorts. He later became an assistant to the great architect Christopher Wren, and, as Chief Surveyor to the City of London, was responsible for overseeing more than 50% of the rebuilding of London following the Great Fire of 1666.
An architect in his own right, few of his buildings survive today, but a drawing in 1858 of his Royal College of Physicians (completed 1678) shows rising sashes in every visible elevation.
Wikipedia quotes Ham House as an early example, but this house dates from 1610, and has been extensively refurbished by successive owners over the centuries. Whether the windows are originals or not is conjectural, but to me, it seems unlikely that they could all have survived as well as they have from that early date. I look forward to being corrected by others, on this point.
A very early reference to sash windows appears in a diary entry of Robert Hooke's dated Feb 2nd 1680 (http://www.roberthooke.org.uk/batten6.htm)
This is the earliest known reference to sash windows, although sliders of one sort or another have been with us since the dawn of time. Unglazed openings were shuttered with wood boards, and a sliding version survives to the present day as the horizontal Yorkshire Slider. As glass became available, solid boards were simply replaced with frames, and further improved over time: Simple, economical, and uncomplicated.
The invention of the rising sash will almost certainly have been prompted by the fashion among the wealthy for Palladian-style buildings where window openings are taller than they are wide. This style was introduced in the late sixteenth century but was not widely adopted. It became fashionable in the late seventeenth century, during Robert Hooke's lifetime. But whether he, or some unknown but enterprising joiner, conceived the idea of counter-balancing the sashes with weights concealed in cased boxes, we may never know. The story is further confused by the fashion, from time to time, to give houses complete make-overs, throwing out the old and replacing with new. (So what's changed?)
There are clues, though, when dating a particular window, as styles and construction techniques changed over the years. This is not an exact science, however, as alterations, copies and even the possibility of downright fakes all have to be taken into consideration.
In general terms, the early sash windows were constructed with solid, plain glazing bars, perhaps relieved by a slight bevel, glazed with hand-made 'cylinder' glass. It is these imperfect panes, with their inevitable undulations, pits, and reams, which give old windows a sparkle when seen from afar as the light is caught and scattered.
Initially the window frames were generally inserted directly into the structural opening to leave the cased box completely visible from outside. This feature on its own is not a sure sign of antiquity, as an old-ish window may be inserted in a new-ish building in just the same way. However, the cased box hiding the weights is a bulky item and it must have soon occurred to a builder that concealing the box in a rebate built into inside face of the (solid) brick or stone wall would greatly increase the amount of light for a given structural opening (and, also, solar gain on a sunny winter's day in an era without central heating).
Over the years, architects and their joiners competed to improve their designs over those of the neighbours. Frames became lighter, and glazing bars became elegantly moulded and ever slimmer, culminating in the slender lambs-tongue profile which is the ultimate development of the ovolo mould. (Many modern replacements, of course, can be instantly spotted from the far side of the room by the rounded moulding at the junctions, where the ovolo was applied by a power-router after the frame was assembled. Ugh!)
As technology produced ever-larger panes of glass, glazing bars became fewer in number, (except where they were used for purely decorative purposes) shown by the proliferation of Victorian houses with but a single vertical glazing bar. By the turn of the century glass was available in large rolled or drawn sheets, and many elegant sash windows of the early 1900s have no glazing bars at all, relying on delightful proportion for their merit, and decoration, if any, being provided by arches and curves in the main structural components. The chief driver of this process being, as always, first-cost, bringing a fine product to the mass market.
The aim of the designer is generally to achieve the most pleasing balance of proportion and economy. Ostentatious display may be recognised in the inappropriate proliferation of glazing-bars and arched rails used simply to demonstrate the wealth of the client. Wherever you look, you should be able to recognise these features. In general, the rising sash window forms a major part of our British architectural heritage, and deserves every effort to preserve and improve it for the benefit of future generations.
Useful links:
www.supasash.com
www.rugbysash.co.uk
http://forum.expertexpert.com
www.roberthooke.org.uk
Copyright KJN 2011
the greenest option
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