Options for narrowboat windows are many and varied, the choice will be yours and difficult. Screw in frames with visible screws, screw in frames with hidden fixings (concealed behind a coloured insert) or clamp in frames, fixed to the cabin using internal clamps to pull the window tight to the cabin side leaving a smooth, unblemished exterior frame. Mitred tops with radius bottoms, mitred all round, radius all round, top hopper, hopper slider, arch top etc.
Standard hopper style windows consist of a fixed bottom pane of glass and have a smaller top glass which can be opened at sits back into side hoppers or onto specially designed window catches.
Full Slider Windows
Consist of one fixed and one sliding pane of glass and are a good method of allowing ventilation within the galley area. Your chosen manufacturer will need to know which side of the boat you want to fit the window because the fixed pane of glass should be towards the front of the boat.
These have the opening hopper at the top and the bottom section has one fixed and one sliding pane.
Fully Opening Windows
consists of a single pane of removable glass which when opened sit back into either side hoppers or special catches which not only act as locks but also when released, hold the glass in the open position. These windows have the added benefit of acting as an escape window in the event of an emergency. They are also extensively used in canal hire fleets but still look and operate well on private boats.
Double Glazed Option
All of the above, except sliding windows, are available as double glazed units which will retain heat, cut down on noise and help to eliminate condensation.
Thermal Break Double-Glazed Windows
Thermal break double-glazed windows have solved the problem of making narrowboat portoles and radiused (curved corner) double-glazed aluminium frame windows with a thermal break in the frame. The thermal break means that less heat can be transfered between the inner and outer sections of the frame, which cuts down a large amount of condensation and heat loss. Early adopters of this technology report that condensation has all but been eliminated. While thermal breaks have been possible in square-edged windows, it has been an advance in making them fit in curved edges, thus retaining the style.
The process uses a polyamide thermal insert between the inner and outer sections of the frame to give an extra thermal barrier. The windows have been able to hide fixings and can be supplied with radius or mitred corners, arch tops and in hopper style, fixed or fully opending and powder coated in any colour, or anodised. The thermal breaks would add around 15% to the cost of a typical narrowboat window, with the most popular size 36in x 21in.
Plain aluminium which will degrade over a period of time, bright or satin anodising or even powder coating which can be supplied in any colour in the chart and is easily touched in if damaged by branches, feet or another vessel