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Sanded blue
Flat window sill with a raised edge
  • Authentic Belgian blue stone
  • Easy to configure
  • Gray or blue sanded finish
  • Renier: Top Quality from Our Own Quarry
Miter Cut Option
By default, a miter cut is always 45°, either with an inside or outside angle. Other angles are possible; please specify this clearly in the "Comments" field (at checkout).
Drawing of an L-shaped mitered door sill (interior)
Cushion Options
To ensure a proper fit with other building components, it may be helpful to place a shim on a threshold. Either the 1-centimeter-thick shim extends across the entire width, or it stops 5 centimeters from the front (see drawing) It is not possible to combine a cushion with a miter joint.
Flat threshold made of blue stone with an upstand and a cushion

Flat window sill with a raised edge

€ 0,00

Price per item, including VAT

€ 0,00

Price per square meter, excluding VAT and without options

Easily customize your ideal flat window sill with an upstand and drip groove right here. Select the desired finish, thickness, length, and width below, along with any optional features. The price per piece and per m² is calculated automatically. You can always adjust the finish as desired. Then click “Add to Cart” and complete your order. Delivery time: 2 weeks.

Please note that the thickness (or height) of the threshold is the height of the back edge. The top surface of the threshold is 1 cm lower than the height of the back edge. For example, a threshold that is 4 cm high is 3 cm thick with a 1 cm upstand. In this case, enter a thickness of 4.

Is the length greater than 180 cm? The threshold will automatically be split into multiple pieces. Enter the desired division using the additional fields that appear.

Available on backorder


L miter cut on the inside
L miter cut on the outside
L Full-width cushion
L The cushion ends 5 cm from the front

R miter cut (inward)
R miter cut on the outside
R Full-Width Cushion
R The cushion ends 5 cm from the front

Total area per piece: 0

Total area: 0

Our Belgian blue stone is one of the most sustainable materials on Earth. This ancient stone, which has been formed over millions of years, is quarried and processed locally in an environmentally friendly and sustainable manner.

You can easily customize this flat window sill with an upstand to suit your own preferences:

  • Blue stone from our own quarry (La Préalle in Sprimont)
  • Finish:
    • Top, front, and both ends (5 cm) sanded blue or gray
    • The front and both ends (5 cm) can optionally be finished with a beveled edge for a stylish look
  • Straight cut, with a drainage groove measuring 0.6 x 0.6 cm, 2 cm from the front edge, ending 2 cm from the machined ends.
  • The edge is glued on; it is 2 cm thick and 1 cm higher than the surface. As an option, it can also be made from solid material for an additional charge.
  • Thicknesses ranging from 4 cm to 11 cm. Please note that the thickness (or height) of the threshold refers to the height of the back edge. The top surface of the threshold is 1 cm lower than the height of the back edge. For example, a threshold that is 4 cm high is 3 cm thick with a 1 cm upstand. In this case, specify a thickness of 4.
  • The width includes the width of the upstand. For example, a threshold that is 18 cm wide is 18 cm wide in total, including the 2 cm width of the upstand.
  • Options:
    • 45° miter
    • 1-centimeter-thick cushions across the entire width
    • 1-cm-thick cushions that end 5 cm from the front
    • Solid window sill (= no glued-on edge), see ‘Build Your Own Flat Window Sill—SOLID’
  • Complete flexibility in dimensions.

Download Technical Data Sheet
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Frequently Asked Questions

What is a window sill with an upstand, and when should I choose one?

This is a window sill with a rear edge that is higher than the top surface. The raised edge allows for a clean connection to the window frame and helps ensure proper waterproofing.

In this version, the upstand is designed according to the selected standard version. A solid version is typically chosen when a single continuous piece is desired.

The door sill is custom-made. The length, width, and total height are determined based on the opening, wall construction, insulation, and the door and window frames.

Depending on the configuration, additional operations may be possible, such as miter cuts and finished end faces. Always clearly specify any special angles or joints when placing your order.

The delivery time is usually about 2 weeks. Special processing or larger quantities may affect the delivery time.