Bay Windows Buyers Guide

Bay Windows Buyers Guide

Bay Windows Cost Estimates

Bay Windows Buyers GuideBefore undertaking the replacement of a Bay Window or even installing a new one, it is important to obtain a cost estimate for the entire work and not just a price per window. The quote is designed to help you, as the homeowner, to see whether to installation work you are considering having done is according you your budget or beyond it.

According to how the quotes works out you can decide if you want to proceed “As-is”, make changes or abandon the idea completely. In order to get an accurate quote a number of factors should be considered at outset, some of which we have outlined below.

1.     Window Style

There are, as you would expect, any styles of bay windows, or the lesser complex alternative, bow windows, but your basic consideration is whether to go with an angled bay (faceted) or one with square corners.

The faceted design is likely to be more complex in design, have more part and more labour intense to both build & fit, so the expectation is that for the same size of opening a faceted bay window will cost the most.

2.     Window Size

The size of the opening is going to determine the dimensions of the window itself, but there are also things to consider if you are enlarging (increasing the width of) an existing opening such as the overhead load bearing lintel. If you are widening the opening then your existing lintel may not be wide enough or strong enough to cope with the new load stresses.

If it is a “floor to ceiling” design are you going to use glass all the way down to the floor or “infill” panels?

The projection of the window will also mean a larger “roof” to the bay. As the window construction extends outwards from the main building the top will clearly need a weather-proofing of some kind.


Two types of materials are prevalent, UPVC & wood being the most popular, although aluminium is an option. Wood can be one of 3 options

  • Hardwood – can be expensive
  • Engineered Wood – versatile and cost effective
  • Soft wood – needs high maintenance to prevent determination

UPVC is long lasting but can look “cheap” if not of a good quality extrusion.

Colour options for wooden bays are just a plentiful as you would want – just choose the colour & buy the tin of paint! UPVC can go to about 5 or six basic options, including appearances mimicking Oak, Ash or Mahogany.

You also have to consider the roofing section – tiled or glazed or composite panels are 3 popular choices.


The nature of the glazing of the window panes can surprisingly turn up some quite marked variations I pricing, just look at the options:

  • Sealed unit gap widths from 6mm to over 20mm
  • Frame profiles – slim to steel reinforced upvc
  • Inert gas filled double glazing
  • Triple glazing
  • Toughened glass or laminated
  • Leaded or coloured glazed panels
  • How many do you want to be able to open?
  • Low-e or low emissivity metallic coated solar glazing
  • Locks & window furniture prices vary as per design
  • Cills & soffits

Any combination of the above will give you a different price for manufacture & installation.

The most time efficient and useful way to make a decision is to get a reputable double glazing company to survey your property and then discuss options with you in-situ.