Choosing the right window sills

Whether you are building your new home, doing a home extension or home renovations, you may need to consider what type of window sills to get.

Luckily, we can help you with that!

Window sill (also known as “Windowsill” and “Window cill”) are an essential part of the home. The primary function of window sills is to protect the window façade from the weather, but they also have great design and decorative functions. External window sills come in variety of different materials and designs to choose from.

What type of window sill should I get?

Choosing the right sill is a decision that should be discussed with your architect and property owner. In Ireland, the 2 most popular options are natural stone sills or concrete sills. This decision is usually made in the initial stages of house planning where homeowners are budgeting and trying to minimize costs in certain areas. It is important to remember that once window sills are installed, they will likely never be changed ever.

Advantages of Natural Stone over Concrete.

Natural stone windows sills give the home a sleek elegant look. Generally, stone windows sill last longer than concreate and do not generate a build-up of moss as easily as concrete sills.

Natural Stone sills require little to no maintenance.

Kilkenny Limestone window sills do not require maintenance as the material is non-porous. This means moisture will not absorb into the stone like it would with other materials.

Silver Granite window sills come with a flamed finish giving the sill a nice textured finish. The variation of color combined in Silver Granite allows them to tie in nicely with any other stone products surrounding it.

A natural stone sill will draw attention to other stone features surrounding it giving the home an overall more elegant look.

Natural Stone is a higher quality material than concrete. A good quality sill will prevent mold and residue from damaging the façade.

What size/depth window sill do I need?

All houses are built individually and so the wall thickness can vary. The different thicknesses of the wall cavity and the depth of the opening will influence what depth you will need.  Always check with the builder before conforming to your sills in order to ensure the depth is sufficient.

The most popular window sill depths are as follows.

220mm – plastered wall

250mm – plastered or some cladding

350/400mm   – stone wall.

** These are estimations – ALWAYS check with your builder for the necessary size required. **

We recommend a minimum of 100mm overhang on each side of the window as standard. This can be increased or decreased if the window is very large or very small.

All window sills should come with a slight gradient to let water flow off of it and drip line 10mm from the end of the sills to make sure the wall does not get water damaged.

How long can one window sill be?

This will depend on the availability of material but generally limestone slabs come in lengths of up to 1.8m. Window over 2 meters will generally come in 2 halves. If you do require a particularly long piece, you can request specifically, however, this may take longer while waiting for suitable slabs to make the full product.

Can I get the corner window sills cut?

Yes! Corner window sills are becoming more and more popular in newly build houses. Corner windows will be cut at a 45-degree angle to fit nicely together.

Specialized Window Sills.  – My Window is curved/I need a specialized window sill made to fit my feature window.

That is no problem. If you have a very specific requirements for a window sill, we will be able to make a piece suitable for you. To do this we will need an exact measurement or possibly a template of the sill you are hoping to get made. Once we have this, we will be able to provide a quotation for the sill.  

What are the window sills’ dimensions?

See the drawing below outlining our limestone window sill dimensions.

All dimensions are the same except the depth which varies depending on customers’ requirements. Height, front, and upstand all remain the same.


What are some different style window sills?

Natural stone window sills have 3 popular styles that will suit almost any home.

Sanded, flamed, or combed. Choosing the appropriate finish will depend on the style of your house.

Sanded will provide a smooth, light elegant finish.

Flamed will give the sill a nice textured surface for a traditional look.

Combed sills are riveted to give the home a more aged look.

If you are considering buying window sills for your home we highly recommend calling and talking to our sales team who will be happy to have a look at your home drawings and put a list together for you.

Check out some jobs we have completed. LINK

Call us today.

Window Sill Dimension