Frames and seals
The profile design, thermal breaks or chambers and seals affect heat transfer through the frame. We compare system performance, not just the number of chambers.
Our range / Windows
Energy-efficient windows
Every window has a defined level of thermal insulation. “Energy-efficient windows” are structures designed to reduce heat loss and characterised by a low Uw value. The frame, glazing unit and their connection determine performance. When preparing a quotation, we compare whole-window specifications and account for installation and building ventilation.
Application
Choosing windows for a new home or renovation
For a new building, the design requirements are the starting point. When replacing existing windows, we also assess the condition of the reveals, façade insulation and the ability to seal the joints correctly. This ensures the choice of windows and doors reflects the conditions in which they will be used.
More airtight windows can reduce uncontrolled draughts. Rooms still need planned air exchange. We therefore discuss ventilation before ordering, especially if the existing windows have ventilation inlets.
Insulated glazing unit
Low-emissivity coatings, the glazing unit construction and the spacer all contribute to thermal performance. We select glazing alongside an assessment of weight, daylight and sun exposure.
Connection to the building
We select the installation and sealing method to suit the wall and facade layers. We account for connections at sills and thresholds to reduce areas of increased heat loss.
Before choosing
Thermal insulation values
- Uw — the whole window
- The thermal transmittance of the complete window. A lower value means better thermal insulation. We compare windows with the same dimensions and divisions.
- Ug — glazing unit
- This describes heat transfer through the glazing. A favourable Ug value matters, but it is not the same as the value for the whole window.
- Uf — the frame
- This refers to the frame's insulation performance. Together with the glazing, its edge spacer and the proportions of the assembly, it affects the final Uw value.
Questions before buying
Energy-efficient windows — what should you know?
Is triple glazing worth choosing?
Triple glazing can offer better thermal insulation than comparable double glazing. However, we base the decision on the whole window’s performance, weight, size and the building’s needs. We also check light and solar energy transmission.
Can PVC, aluminium and timber windows be energy efficient?
Yes. Well-insulated designs are available in each of these materials. We compare specific systems and configurations, because the material name alone does not determine the final Uw value.
How much can replacing windows save on heating?
The result depends on factors including the condition of existing windows and doors, building insulation, ventilation and heating. It will differ for each home. Our quotation sets out the proposed windows’ properties; energy demand can be assessed through an analysis of the whole building.
Material and construction
Choose your window material
Explore the available systems and construction options. We determine the required performance for the specific construction.
Talk to us
Choose energy-efficient windows.
We will compare assemblies and performance for your dimensions and agree the installation method. Book a free measurement visit.