Rehau TOTAL70 vs TOTAL70 Edge: Which uPVC Casement Should You Choose?

Rehau's TOTAL70 is one of the most widely fitted premium uPVC casement systems in the UK, and it comes in two forms: the standard TOTAL70 and the thermally upgraded TOTAL70 Edge. They share the same 70mm frame, the same colour range and the same security, so the choice comes down to one question — how much thermal performance does your home actually need? This guide sets the two side by side and shows where each earns its place.

What TOTAL70 and TOTAL70 Edge Have in Common

Both profiles use a 70mm frame depth, steel-reinforced sashes, internally beaded glazing so glass cannot be removed from outside, and PAS 24:2022 security with multi-point locking. Both are available across the full Rehau colour and woodgrain range, including anthracite grey, Chartwell Green and dual-colour options. Both reach A+ on the BFRC energy scale — the highest rating commonly specified. In other words, on looks, security and colour, there is nothing to separate them.

The One Difference: Chambers

The difference is inside the profile. TOTAL70 has a 5-chamber construction; TOTAL70 Edge adds a sixth internal air chamber. Air chambers are the primary insulator in any uPVC frame, so the extra chamber on the Edge improves thermal performance at the seal, where heat is most easily lost. Standard TOTAL70 already achieves whole-window U-values from 1.2 W/m²K with double-glazed Low-E units, dropping to around 0.9 W/m²K with triple glazing; the Edge improves on this again, which matters most on the coldest elevations of a house.

For context, current Building Regulations (Approved Document L) cap replacement windows at 1.4 W/m²K, so standard TOTAL70 already clears the threshold comfortably. Standard TOTAL70 meets the rules with room to spare; the Edge is for pushing beyond them on the elevations that need it.

When Standard TOTAL70 Is the Right Choice

For most rooms in most homes, standard TOTAL70 is the sensible specification. It is A+ rated, comfortably exceeds Building Regulations, and pairs the full colour range with strong security. On south and east-facing elevations, sheltered sites, and rooms that are not the coldest in the house, the standard profile delivers everything a premium replacement window should. Our Rehau uPVC range is built around TOTAL70 for exactly this reason.

When the Edge Upgrade Pays Off

TOTAL70 Edge makes sense where thermal performance is the priority: north-facing elevations that never see direct sun, exposed or coastal sites, rooms that run cold, and refurbishments aiming beyond baseline compliance toward Future Homes Standard-aware performance. Specifying the Edge only on the elevations that need it — rather than the whole house — is often the smartest way to spend the difference, and something we work through opening by opening at survey.

How to Decide

Start with the coldest rooms and the most exposed elevations, and specify the Edge there; use standard TOTAL70 elsewhere. Both carry the same A+ rating, the same security and the same colours, so mixing them across a house is seamless and no one will see a difference from the street. If you would rather keep it simple, standard TOTAL70 throughout is a specification no one regrets. Vitrum Solutions fabricates both in-house at our Uxbridge workshop and fits them with our own team — see the full TOTAL70 breakdown or explore uPVC casement windows. Our independent Rehau windows review covers how the range performs in service.

Frequently Asked Questions

What is the difference between Rehau TOTAL70 and TOTAL70 Edge?

They share the same 70mm frame, colours, security and A+ BFRC rating. The difference is chambers: TOTAL70 has a 5-chamber profile, TOTAL70 Edge has a sixth air chamber for better insulation at the seal. The Edge delivers slightly better thermal performance, which matters most on cold or exposed elevations.

Is TOTAL70 Edge worth the upgrade?

It depends on the elevation. On north-facing, exposed or cold rooms, the sixth chamber's improved insulation is worth it. On sheltered or sun-facing elevations, standard TOTAL70 already exceeds Building Regulations and is the sensible choice. Many homes specify the Edge only where it counts and standard TOTAL70 elsewhere.

What U-value does Rehau TOTAL70 achieve?

Standard TOTAL70 achieves whole-window U-values from 1.2 W/m²K with double-glazed Low-E units, dropping to around 0.9 W/m²K with triple glazing. Both comfortably exceed the Approved Document L cap of 1.4 W/m²K for replacement windows. TOTAL70 Edge improves on these figures again with its additional chamber.

Can I mix TOTAL70 and TOTAL70 Edge in the same house?

Yes. Both use the same 70mm frame, the same colour range and identical hardware, so they are visually indistinguishable once fitted. Specifying the Edge on cold or exposed elevations and standard TOTAL70 elsewhere is a common and cost-effective approach, and the mix is invisible from the street.

Are Rehau TOTAL70 windows secure?

Yes. Both TOTAL70 and TOTAL70 Edge are PAS 24:2022 certified with multi-point shootbolt locking, steel-reinforced frames and internally beaded glazing so the glass cannot be removed from outside. Laminated inner glass and Secured by Design-compatible configurations are available on request.