Specialist Sill Supplier. Manufactured in Dublin.

Window Sills for Every Irish Project

Cills.ie supplies made-to-measure aluminium window sills, external insulation sills, and powder coated sill solutions across Ireland. Every sill is manufactured in Dublin to your exact dimensions, finished in your chosen RAL colour, and delivered to site ready to install.

Made to measure 3 to 5 day turnaround 200+ RAL colours Nationwide delivery
Get Your Price Online 📞 +353 1 223 8774
Cills.ie online platform for ordering made-to-measure window sills in Ireland with RAL colour selection and instant pricing
Sill Solutions

Sill Solutions for Irish Construction

Whether it is a single replacement sill or a full set for a 50-unit development, we supply the right sill for every project type across Ireland.

Window Sills for New Builds

Aluminium window sills specified at design stage and delivered to site ready to fit. Compatible with timber frame, block, ICF, and steel frame construction methods used across Ireland.

Replacement Sills for Retrofit

Made-to-measure sills for existing window openings. No modification to reveals needed. Ideal for replacing damaged concrete, timber, or stone sills during renovation work.

External Insulation Sills

Purpose-designed sills for EWI and ETICS systems. Projections sized to cover full insulation depth with correct overhang. The most common sill type ordered through Cills.ie.

Sills for Energy Upgrades

Supporting thermal envelope continuity at window junctions. Correct sizing eliminates cold bridges at sill level and helps meet BER, NZEB, and passive house performance targets.

Commercial and Multi-Unit Sills

Volume supply for apartment developments, offices, schools, and public buildings. Batch consistency in colour and dimensions across hundreds of identical openings.

SEAI Grant Compatible Sills

Our aluminium sills are suitable for energy upgrade works funded under SEAI home energy grants. They meet the finish and performance standards required for grant compliance.

Made to Measure

Window Sills Made to Your Exact Dimensions

Every window opening is different. That is why we do not sell off-the-shelf sills. You provide the width, projection, and return details, and we manufacture a sill that fits your opening precisely. No cutting on site. No guessing. No waste.

  • Straight window sills formed to your exact width and projection
  • Bay and angled sills for 3-segment, 5-segment, and custom angle windows
  • Formed end returns, stop ends, or open ends to match your wall detail
  • Projections from 50mm to 400mm for external wall insulation
  • Single-piece sills up to 3000mm in length
Window sill measurement diagram showing width, projection, and return dimensions for made-to-measure ordering in Ireland
Custom
Every dimension, your spec
Why Aluminium

Why Aluminium is the Preferred Sill Material in Ireland

Concrete cracks. Timber rots. Stone stains. Aluminium handles the Irish climate without degrading, requires zero maintenance, and holds its colour for decades. It is now the standard sill material for modern construction and retrofit work across Ireland.

Weather Resistant

No warping, cracking, or moisture absorption in Irish weather conditions.

30+ Year Lifespan

Powder coated finish retains colour without repainting or treatment.

Lightweight and Rigid

2mm marine-grade aluminium. Easy single-person installation.

Full RAL Colour Matching

200+ RAL Classic colours. Match windows, doors, fascia, or render.

Aluminium window sills installed on a modern Irish home showing clean lines and powder coated finish
2mm
Marine-grade aluminium
External Insulation

External Insulation Sills for EWI and ETICS Projects

When external insulation is applied, every window opening gets deeper. The original sill no longer reaches the outer face. Installing a sill that is too short leaves a gap between the sill edge and the render line. Filling that gap with silicone is not a solution. It cracks within months, and water finds its way behind the insulation board.

The correct approach is a made-to-measure aluminium sill with a projection calculated to cover the full insulation thickness plus 40mm minimum overhang.

  • Projections calculated to cover full insulation thickness plus 40mm minimum overhang
  • Formed drip edge prevents water running back against the insulated facade
  • Compatible with EPS, mineral wool, and phenolic insulation boards
  • Eliminates cold bridging at sill junctions when correctly sized
  • Powder coated finish unaffected by render, adhesive, or basecoat contact
View Aluminium Window Cills
External insulation sills fitted on Irish retrofit project showing correct projection depth over EWI system
400mm
Max projection depth
Do Not Patch. Fix It Properly.

Silicone Will Not Fix Wrong Measurements

When sills do not fit, the temptation is to fill gaps with silicone. But silicone cracks, shrinks, and lets water through within months. The only lasting solution is a correctly sized sill, manufactured to your exact measurements.

Silicone Will Not Fix a Wrong Sill

When a sill is too short, too narrow, or the wrong projection, the common fix is to fill the gaps with silicone. But silicone is not a building material. It shrinks, cracks, and separates over time. Water finds its way in. The problem returns, worse than before. The only real fix is a correctly sized sill from the start.

Gaps Let Water In, No Matter What You Seal Them With

A sill that does not cover the full wall thickness leaves exposed junctions. Silicone or mastic may hold for a few months, but Irish weather breaks every temporary seal. Water penetrates behind the insulation, causes damp, and damages the structure beneath.

Undersized Sills Break the Thermal Envelope

An incorrectly projected sill creates a cold bridge at the window junction. This drops the wall U-value, causes condensation on internal surfaces, and can void your insulation warranty. No amount of sealant will restore the thermal performance that a correctly sized sill provides.

Wrong End Details Create Repeat Callbacks

Open-ended sills or missing returns send water down the facade at every rain event. Patching with silicone is a temporary fix that leads to repeat call-backs, unhappy clients, and reputational damage. Formed returns and stop ends solve the problem permanently.

Measure with CILLS

What You Can Measure with the CILLS App

Use the CILLS app on iOS or Android to measure on site, define every detail, and send ready-to-manufacture orders directly from your phone. Each product links to its full product page on Cills.ie.

Window Cills

Straight and bay sills with guided measurement and 3D preview.

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Complex Cills

Multi-fold and stepped profiles for difficult facade details.

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Parapet Capping

Secret-fix system for parapet and boundary walls.

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Flashings

Custom folded flashings and trims for roof and wall junctions.

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Aluminium Planters

Bespoke planters for residential and commercial projects.

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View All Products on Cills.ie

From Measurement to Delivery in 4 Steps

A simple, transparent ordering process. Measure, specify, confirm, and receive your sills on site.

01

Measure Your Openings

Record width, projection depth, and return dimensions for each window. Our measurement guide shows exactly what to capture.

02

Choose Colour and Profile

Select your RAL colour and confirm end details, drip edge profile, and finish type. See a preview of your specification before committing.

03

Review and Confirm

Check your order with transparent per-item pricing. No hidden charges, no minimum order value. Confirm and your sills go into production.

04

Manufactured and Delivered

Precision-formed from 2mm aluminium and powder coated in Dublin. 3 to 5 business day turnaround with tracked delivery to your site.

Your Sill Supplier

Why Contractors and Builders Choose Cills.ie

We are a specialist sill supplier built specifically for the Irish construction industry.

Manufactured in Dublin

Our own workshop in Dublin means shorter lead times, hands-on quality control, and the flexibility to handle urgent or non-standard requirements.

3 to 5 Day Turnaround

From order confirmation to dispatch in 3 to 5 business days as standard. Faster turnaround can be arranged for time-critical projects.

Every Sill Made to Your Dimensions

No stock sizes, no trimming on site. Every sill is produced to the exact width, projection, and return dimensions you specify.

Delivery to All 32 Counties

Tracked delivery nationwide including Northern Ireland. Free delivery on orders over €150. Sills arrive protected and ready for installation.

Specification Support When You Need It

Not sure about projection depth or end details? Our team can advise on the correct specification for your wall build-up and insulation system.

Purpose-Built for the Irish Market

Our products, pricing, and service are designed for the way Irish contractors, builders, architects, and homeowners work.

Customer Reviews

Trusted by the Irish Construction Trade

From single-home retrofits to large-scale developments, contractors and architects rely on Cills.ie for consistent sill quality and reliable supply.

★★★★★
"We use Cills.ie for every external insulation job. The sills always fit, the colour is always right, and turnaround is consistently fast. It has simplified our supply chain."
DB
Declan Byrne
EWI Contractor, Byrne Insulation Services, Wicklow
★★★★★
"Ordering window sills used to mean phone calls, emails, and waiting days for a quote. Now I enter my measurements, pick a colour, and get an instant price. The quality of the finished product is excellent."
NW
Niamh Walsh
Project Manager, Walsh Construction Group, Cork
★★★★★
"We specified powder coated aluminium sills on a 40-unit apartment scheme. Every sill was identical in colour and dimension. That kind of consistency matters on large projects."
EF
Eoin Flanagan
Director, Flanagan Development Group, Galway
★★★★★
"For passive house detailing, sill tolerances are critical. Cills.ie delivers to the millimetre. That precision is hard to find from general suppliers."
AB
Aoife Brennan
Architect, Brennan Design Studio, Dublin
FAQ

Window Sills in Ireland. Your Questions Answered.

Common questions from contractors, builders, architects, and homeowners ordering sills from Cills.ie.

Yes. We manufacture in Dublin and deliver to all 32 counties including Northern Ireland. Delivery is free on orders over €150. You will see the exact delivery cost and estimated timeline at checkout.
Every sill is manufactured to the dimensions you provide. We do not sell standard stock sizes. You specify the width, projection, end details, and colour. We produce the sill to match your exact requirements.
We manufacture straight window sills, bay window sills (3-segment, 5-segment, custom angles), sills with formed returns or stop ends, and sills with deep projections for external insulation. If you have a non-standard requirement, contact us to discuss.
Yes. Aluminium sills are the preferred choice for EWI and ETICS projects. We manufacture sills with projections up to 400mm to cover full insulation depth with adequate overhang. They resist moisture, do not degrade under render, and maintain their shape long term.
There is no difference in the product. "Cill" is the traditional Irish and British trade spelling. "Sill" is the more widely used general English spelling. Both refer to the horizontal ledge at the base of a window opening. At Cills.ie we use both terms interchangeably.
Yes. We offer the full RAL Classic colour range with over 200 colours. All sills are powder coated in a factory-controlled environment for a durable, consistent finish. Popular choices include RAL 7016 (Anthracite Grey), RAL 9005 (Jet Black), and RAL 9016 (Traffic White).
Standard turnaround is 3 to 5 business days from order confirmation. Delivery typically adds 1 to 2 business days depending on location. Dublin-area orders may be available for collection sooner.
No. Silicone is not a substitute for a correctly sized sill. It shrinks, cracks, and separates in Irish weather conditions, allowing water behind the insulation and into the wall structure. The only reliable approach is a made-to-measure aluminium sill produced to the exact dimensions of your opening.
No. You can order a single sill or hundreds. There is no minimum order value or quantity requirement. Delivery is free on orders over €150.

Dublin Workshop

Local manufacturing for fast turnaround and hands-on quality control

Nationwide Delivery

Tracked delivery to all 32 counties. Free on orders over €150.

Specification Support

Direct access to our team for measurement and specification advice

Explore More Products

Aluminium Window Cills

Custom cills with 3D preview and guided measurement

Bay Window Sills

Multi-segment bay sills for period and modern homes

Aluminium Capping

Parapet capping and copings to your dimensions

Aluminium Flashings

Weather protection flashings for walls and roofs

Welded End Caps

Factory-welded sill ends — no silicone, no bonded caps

Welded Upstands

Raised rear lip sealing the sill-to-frame junction

Gutters & Downpipes

Aluminium rainwater systems colour matched to your sills

Fascia & Soffit

Maintenance-free aluminium roofline panels

Roof Trims

Verge, drip, ridge and eaves trims in any RAL colour

Ready to Order Your Sills?

Whether you are a contractor ordering for a live site, an architect specifying for a new build, or a homeowner upgrading your home, Cills.ie supplies made-to-measure sills across Ireland.

Get Your Price Online 📞 +353 1 223 8774
No minimum order Transparent pricing SEAI grant compatible