1L TH Transom + TH Main (Tall) uPVC Casement Window — Made-to-Measure
From £216 · 10–14 working day lead time · Free delivery over £1,450 · UK-fabricated Rehau Total 70 profile
Sizes available: 400–1300mm wide × 800–2400mm tall.
Price range: £216 (smallest size) to £574 (largest size).
Configure size & options →About the 1L TH Transom + TH Main (Tall)
Tall 1-light with two top-hung openers stacked. Maximum ventilation in tall apertures. Built on the Rehau Total 70mm chamfered uPVC profile with concealed drainage and trade reinforcement. A-rated double glazing as standard. Made to your exact size — enter the dimensions and the configurator gives you the live price.
Common applications include houses, flats, period restorations, and replacement windows in social housing and developer projects. The 1L TH Transom + TH Main (Tall) ranges from £216 (smallest grid size) to £574 (largest), with no VAT to add — Glazing Quoter is not VAT-registered, so the displayed price is what you pay.
How does the 1L TH Transom + TH Main (Tall) compare?
| 1L TH Transom + TH Main (Tall) | Side Hung 1L | Sliding Sash | |
|---|---|---|---|
| Maximum opener aperture | ~30% of window | ~80% of window | ~50% of window |
| Best use | Bathrooms, hallways, above kitchen worktops | Bedrooms (egress), wide rooms | Period properties |
| Hinge location | Top of frame | Side of frame | Vertical sliders |
| Cleaning external | Reach-from-inside (limited) | Easy reach-from-inside | Tilt-clean possible |
| Typical price | From £216 | From £120 | From £550 (sash) |
Top-hung styles ventilate without rain ingress and suit ground-floor windows where security or restriction matters.
Building Regulations & compliance
Part L (thermal) — every Glazing Quoter casement uses A-rated 28mm sealed double glazing with low-E soft-coat inner pane and argon fill. Whole-window U-value 1.4 W/m²K (typical). Building Regs minimum is 1.6.
Part F (ventilation) — trickle vents are included as standard on the 1L TH Transom + TH Main (Tall) (top-edge of frame). Required by current Building Regs for habitable rooms, kitchens, and bathrooms.
Part N (safety glass) — required within 800mm of the floor or in any pane next to a door. Toughened glass adds approximately +15% to the price; Toughened + Obscure (combined) adds +26.5%. The configurator prompts you to set this based on installation height.
Part B (means of escape) — for habitable rooms (bedrooms, living rooms), the openable area must be at least 0.33 m² with no dimension less than 450mm. The 1L TH Transom + TH Main (Tall) satisfies this above 500×900mm — the configurator confirms each size you enter.
How to install (3-step summary)
- Measure — brick-to-brick aperture, subtract 5–10mm tolerance. Full guide: /how-to-measure.html.
- Order — configure your 1L TH Transom + TH Main (Tall) above. 10–14 working day lead time.
- Install — packers, fixing screws (typically 4 per side), external silicone, internal architrave. Full guide: /installation-guide.html.
FAQs
What is the lead time for a 1L TH Transom + TH Main (Tall)?
All Glazing Quoter casement windows are made to your exact size. Lead time is 10–14 working days from order confirmation. Once manufactured, you'll receive a delivery date by email.
What sizes can I order?
The 1L TH Transom + TH Main (Tall) is available between 400mm and 1300mm wide, and 800mm to 2400mm tall. Enter your exact aperture size at the configurator and the price updates live.
What's included in the price?
The price you see (from £216) includes the full window: Rehau Total 70 frame, A-rated double glazing, hardware, 150mm sill, trickle vent, and a 10-year guarantee. Free delivery applies on orders over £1,450 to England and Wales mainland.
What glass options are available?
Clear (standard), Obscure (privacy — recommended for bathrooms), and Toughened (Building Regs Part N — required within 800mm of the floor or beside doors). Obscure + Toughened can be combined.
Do I need toughened glass for the 1L TH Transom + TH Main (Tall)?
Toughened glass is required by Part N if the bottom of the glass sits within 800mm of the floor, or if the window is next to a door. The configurator asks this so you don't miss it.
Can the 1L TH Transom + TH Main (Tall) serve as fire egress?
If the openable area exceeds 0.33 m² with a minimum 450mm in either dimension, the 1L TH Transom + TH Main (Tall) satisfies Part B (means of escape) for habitable rooms. Most 1L TH Transom + TH Main (Tall) sizes meet this.
1L TH Transom + Fixed Main
1L Narrow: Fixed Transom + SHL
2L Wide: 2× TH Transoms + 2× Fixed