Colonial Wood Finish
Traditional Colonial wood casing with layered mouldings that step outward from the window. Timeless, formal, and takes paint or stain beautifully — a signature look for heritage homes and dining rooms.
Customize Your Windows
Interior Window Trim & Casing Options
Casing profiles installed across Ontario — Colonial with 45° rosettes, vinyl stepped with rosettes, and more. Pick the trim that finishes your new windows the way your interior deserves.
The Basics
Jamb Extension vs. Casing — What's the Difference?
Every window installation includes two interior finishing components, and knowing the difference helps you make the right choice for your home.
The jamb extension is the frame depth that bridges the gap between the window unit and the plane of your drywall. Wall thicknesses vary from home to home across Southern Ontario — especially between older brick houses and newer builds — so jamb extensions are sized to your exact wall depth for a seamless fit.
The casing (often called "trim") is the decorative moulding installed over the joint between the jamb extension and the wall. It's the visible finish frame most homeowners picture when they think of window trim, and it's what ties your new vinyl windows into the look of the room.
Wood or Vinyl — Two Quality Casing Options
Trust Build offers interior finishing in two material families, both installed by certified crews:
Solid wood. Jamb extensions and wood casings come in pine, oak, and other quality wood species — never MDF. Solid wood holds fasteners better, resists dents and moisture swelling, and takes finish beautifully. Wood casing profiles include colonial, flat, and stepped styles.
Vinyl. Low-maintenance vinyl casing is available as colonial casing with round rosettes or 45-degree rosettes, and as stepped vinyl casing with matching stepped rosettes. Vinyl arrives pre-finished, never needs painting, and wipes clean — a practical match for busy households and moisture-prone rooms.
Finished Your Way
Wood trim can be completed two ways:
- Painted — we supply primed wood, ready for a smooth, uniform painted finish in any colour that suits your interior.
- Stained — we supply unprimed natural wood, so the grain takes stain beautifully for a warm, traditional look.
Prefer to have it done for you? Trust Build can provide professional painting or staining as part of your project — finished to your specifications, so your energy-efficient replacement windows are truly complete the day the installation wraps up.
From flat modern lines to full colonial profiles with rosettes, there's a casing style for every home — from century houses in Barrie to new builds across Southern Ontario.
Casing Profiles
Choose the casing style that suits your interior.
Every casing profile is available on every window we install — casement, awning, single-hung, slider, picture, bay and bow. Custom widths, painted finishes and matched heritage profiles quoted on request.
Flat Wood Casing
Clean, single-plane flat wood casing with crisp edges. Modern, understated, and versatile — pairs equally well with contemporary interiors and transitional builds.
Flat Wood Finish — Black Window
Flat wood casing painted white, framing a black-interior window against a dark grey wall — showing how the crisp white profile lets an architectural black sash stand on its own.
Stepped Casing
Layered stepped casing with a clean architectural profile. The stepped mouldings add depth and shadow lines that read as crisp and contemporary against saturated wall colours.
Vinyl Finish with Round Rosettes
Low-maintenance vinyl casing with round rosette blocks at each corner. Arrives pre-finished, never needs painting, and wipes clean — a decorative option that suits busy households.
Vinyl Finish with Round Rosettes — Light Interior
The same round-rosette vinyl profile shown against a soft light-grey wall — a subtle, formal detail that reads elegant without dominating the room.
Vinyl Stepped Casing with Stepped Rosettes
Layered vinyl casing paired with stepped rosette blocks at each corner. The stepped profile in the casing and the rosettes echo each other — clean, architectural, low-maintenance. A modern take on traditional trim that never needs repainting.
Colonial Casing with 45° Rosettes
Traditional Colonial profile with angled 45° rosette blocks at each corner. The rosettes replace mitred joints — a heritage detail that reads formal without being ornate. A common upgrade on front-of-house rooms and dining spaces.
Colonial Casing with 45° Rosettes — Beige Interior
Colonial casing with 45° rosettes installed on two windows in a beige-toned bedroom — showing how the white profile lifts warm neutral wall colours and complements existing baseboard.
Stained Wood Colonial Casing — Heritage Interior
Solid wood colonial casing finished in a rich dark stain, framing a casement-over-awning window in a century home. The unprimed natural wood takes stain beautifully — a warm, traditional look that complements exposed brick, wood beams and heritage interiors.
FAQ
Frequently Asked Questions
The jamb extension is the depth of the window frame that runs from the window unit itself to the plane of your interior drywall — it fills the gap so the wall doesn't step down into the rough opening. Casing (or 'trim') is the decorative wood or vinyl moulding installed over the joint between the jamb extension and the wall, covering the seam and finishing the opening.
Standard-width flat casing is included on every brick-to-brick and hybrid installation. Upgraded profiles (Colonial, stepped, rosette blocks) and custom widths above 3½" are quoted as an add-on. Retrofit (insert) installs re-use the existing interior casing — the original trim stays in place.
Yes — we routinely match casing profiles on partial-home projects so new windows blend seamlessly with the untouched rooms. Bring a small offcut or clear photo of an existing casing corner to the assessment and we'll spec the closest matching profile.
Trust Build uses solid wood — pine, oak, and other quality wood species — for jamb extensions and wood casing. We never use MDF. Solid wood holds fasteners better, resists dents and moisture swelling, and takes paint or stain beautifully for a long-lasting finish.
Yes — any casing profile can be sprayed in the colour of your choice, including matte black, warm greys and custom Benjamin Moore matches. Painted-black casing pairs particularly well with our black-interior vinyl sash option for a modern architectural look.
Yes — traditional stool (interior sill) and apron (skirt below the sill) configurations are available on any window that isn't set flush with the floor. Common on kitchen, bay, bow and living-room picture windows.
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No-obligation quote on trim and casing
We bring casing samples to your project assessment so you can see and feel every profile against your existing walls, floors and other trim before you decide.
- Detailed project assessment
- Written itemized quotation
- Product and installation recommendations
- Financing options available
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