Most homeowners choosing between window quotes are comparing prices, not frame construction — which is understandable, since almost every installer's brochure says "energy efficient" and "durable" without explaining what's actually different underneath. Here's what's inside the vinyl frame we install, section by section.
The Frame Material Itself
Our windows are made from an exclusive, 100% lead-free uPVC powder compound. This compound gives the frame better resistance to impact and discolouration than standard vinyl, and it won't crack, blister, or warp — while staying maintenance-free for the life of the window.
- Lead-free uPVC
- Durable and strong
- Energy efficient
- Low maintenance
Jamb Extension
A choice of maintenance-free PVC jamb extensions, frame mouldings, and corner blocks is available to enhance interior finishing, so the window integrates cleanly with your existing trim rather than looking like an obvious retrofit.
Multiple Internal Chambers
Our windows have one of the highest counts of internal air chambers available, which gives them outstanding insulation and sound abatement along with thermal efficiency and increased sturdiness. Each internal wall adds another barrier of trapped, still air — the same principle that makes a double-paned thermos more effective than a single-walled cup.
Fusion-Welded Corners
Fusion-welded corners provide a clean appearance and eliminate the need for adhesives or sealants at the joints. There are no gaps or imperfections on the resulting watertight, airtight surface, and the internal walls are welded too — not just the visible exterior — for added structural strength across the whole frame, not just where you can see it.
Sealed Glass Unit
The sealed glass unit has a 13/16" overall thickness as standard. Depending on the model, different glazing types and thicknesses can be applied — single, double, triple, and Low-E glazing, including a glazed decorative panel in 13/16" or 1-3/8" thickness. If you want the full comparison of what these glazing options actually change for condensation and heat loss, our glass options and warm-edge spacer guide covers that in more depth.
Inside Trim
Interior trim finishes the transition between the window frame and your wall, matched to the jamb extension for a consistent look on both sides of the frame.
Additional Features
- Opening mechanism and high-security multipoint locking system, with stainless steel hinges and tracks
- Hardware mounted through a minimum of two uPVC frame walls for secure, durable fastening
- Depending on the model, casements open to a full 90°
This is the same frame construction behind every vinyl window Trust Build installs. See the full lineup on our vinyl windows page, browse completed installations in our portfolio, or get a free quote to see it in your own home.