Are REHAU Windows Energy Efficient? U-Values, Benefits & Costs Explained
But are REHAU windows energy efficient?
Yes. REHAU is one of the well-known manufacturers of uPVC window and door systems, and its modern window profiles are designed to provide strong thermal insulation when combined with suitable glazing and professional installation.
The overall energy performance of a REHAU window depends on the specific profile, glazing specification, spacer, glass, size and installation. However, modern REHAU uPVC windows can provide significantly better thermal performance than many older single-glazed or poorly insulated windows.
In this blog, we explain REHAU window U-values, thermal efficiency, double glazing, energy-saving benefits and why REHAU windows can be a good choice for UK homes.
What Are REHAU Windows?
REHAU windows are manufactured using uPVC window systems developed by REHAU, a major polymer solutions manufacturer.
REHAU window systems are designed for residential and commercial applications and can be used to create different styles of windows, including:
- Casement windows
- Tilt and turn windows
- French windows
- Bay and bow windows
- Sliding windows
- Fixed windows
- Replacement windows
One of the main advantages of modern REHAU uPVC windows is their ability to combine thermal insulation, durability, security and low maintenance.
For homeowners replacing older windows, upgrading to modern double-glazed REHAU windows can be an effective way to improve the thermal performance of a property.
How Energy Efficient Are REHAU Windows?
The short answer is: REHAU windows can be highly energy efficient when correctly specified and installed.
Their thermal performance comes from several components working together.
These include:
uPVC frame + insulating chambers + double glazing + low-E glass + warm-edge spacer + quality seals + professional installation
The frame helps reduce heat transfer, while the glazing provides another important layer of insulation.
However, it is important not to judge the performance of a window purely by the brand name.
The complete window U-value is more useful when comparing different products.
What Is a Window U-Value?
If you’re researching energy efficient windows UK, you will probably come across the term U-value.
A U-value measures how easily heat passes through a building element.
For windows, a lower U-value generally means better thermal insulation.
For example, a window with a lower U-value will generally lose less heat through the window than one with a higher U-value.
This makes U-values particularly important when comparing:
- REHAU windows
- Other uPVC windows
- Aluminium windows
- Timber windows
- Double glazing
- Triple glazing
When comparing products, homeowners should check whether the quoted U-value refers to the glass Ug-value, frame Uf-value or complete window Uw-value.
The Uw-value is particularly useful because it considers the performance of the complete window rather than just the glass.
What Is the U-Value of REHAU Windows?
The exact REHAU window U-value depends on the particular REHAU profile, glazing specification and window configuration.
Modern REHAU systems can achieve low U-values when combined with suitable energy-efficient glazing.
For example, REHAU’s current window systems can be configured with advanced double-glazing specifications designed to provide strong thermal performance.
This means it is important to ask your window supplier for the Uw-value of the complete window you are being quoted for, rather than simply asking whether the window is “energy efficient.”
At Daylight Glazing, the exact specification can be discussed according to the property’s requirements, including frame, glass and overall window configuration.
Why Does Double Glazing Make REHAU Windows More Energy Efficient?
The glazing unit plays a major role in the thermal performance of a modern window.
Traditional single glazing provides relatively little resistance to heat transfer.
Modern double glazed uPVC windows use two panes of glass separated by an insulated cavity.
That cavity is commonly filled with an inert gas such as argon, helping to reduce heat transfer between the inside and outside.
Low-emissivity, or Low-E, glass can further improve thermal performance by helping reflect heat back towards the interior of the property.
When combined with an insulated uPVC frame, this creates a much more thermally efficient window.
What Makes REHAU uPVC Windows Thermally Efficient?
There are several features that contribute to the thermal performance of modern REHAU windows.
1. Multi-Chambered uPVC Profiles
Many modern uPVC profiles use internal chambers within the frame.
These chambers help reduce direct heat transfer through the frame and improve thermal insulation.
The exact chamber configuration depends on the REHAU system being used.
2. Energy Efficient Double Glazing
The glass specification has a major influence on window performance.
A suitable double-glazed unit can include:
- Low-E glass
- Argon gas
- Warm-edge spacer bars
- Energy-efficient glass coatings
- Toughened or laminated glass where required
3. Quality Seals
Window seals help prevent unwanted air leakage around the opening.
Effective seals can help reduce draughts and contribute to better overall comfort.
4. Thermally Efficient Frame Design
The uPVC frame itself provides an insulating barrier between the internal and external environments.
This is one reason why uPVC remains a popular material for energy efficient replacement windows in the UK.
5. Professional Installation
Even an excellent window can perform poorly if it is installed incorrectly.
Poor installation can create gaps, draughts and thermal weak points around the frame.
For this reason, the quality of installation is just as important as choosing an energy-efficient window system.
Are REHAU Windows Better Than Old Double Glazing?
They can be, particularly when replacing older or poorly performing windows.
Double glazing technology has developed considerably over the years.
Older double-glazed windows may have:
- Higher U-values
- Older glazing technology
- Worn seals
- Deteriorated frames
- Draught problems
- Poorer installation standards
Replacing them with modern REHAU double glazed windows can improve thermal performance and reduce draughts.
However, the improvement depends on the condition and specification of the existing windows.
Can REHAU Windows Help Reduce Energy Bills?
Energy-efficient windows can help reduce heat loss through the building envelope.
When less heat escapes through the windows, your heating system may not need to work as hard to maintain a comfortable indoor temperature.
However, homeowners should be careful about claims that a particular window will save a fixed amount on energy bills.
Your actual savings depend on factors such as:
- Property size
- Existing insulation
- Current windows
- Thermostat settings
- Occupancy
- External temperature
- Ventilation
- Energy usage
- Heating system
Therefore, energy efficient windows can contribute to lower heating demand, but they should be considered as part of the property’s overall energy efficiency rather than a standalone solution.
REHAU Windows vs Aluminium Windows: Which Is More Energy Efficient?
Both modern uPVC and aluminium windows can provide excellent thermal performance when correctly designed.
The main difference is the material and construction.
uPVC naturally has good insulating properties, making it a popular choice for energy efficient uPVC windows.
Modern aluminium windows, meanwhile, use thermal breaks within the frame to reduce heat transfer.
The right choice depends on the priorities of the property.
REHAU uPVC windows can be ideal for:
- Homeowners prioritising thermal insulation
- Replacement window projects
- Traditional homes
- Cost-conscious renovations
- Low-maintenance glazing
Aluminium windows can be ideal for:
- Slim sightlines
- Contemporary homes
- Large glazed areas
- Bifold doors
- Modern extensions
- Heritage-style designs
Rather than choosing a material based solely on energy efficiency, compare the complete window Uw-value alongside design, glazing, security, durability and budget.
Are REHAU Windows Good for UK Weather?
UK homes need windows that can cope with changing weather conditions throughout the year.
Modern REHAU uPVC windows are designed for residential use and can provide resistance against wind, rain and everyday weather exposure when correctly manufactured and installed.
The combination of durable frames, seals and appropriate glazing can help keep the internal environment comfortable throughout the year.
This can be particularly useful during colder winter months when reducing heat loss is a priority.
Are REHAU Windows Low Maintenance?
Another advantage of uPVC windows is their relatively low maintenance requirements.
Unlike traditional timber frames, uPVC does not require regular painting or staining.
For most homeowners, routine maintenance involves:
- Cleaning the frames
- Cleaning the glass
- Checking seals
- Keeping drainage channels clear
- Lubricating moving hardware when required
This makes REHAU uPVC windows a practical option for homeowners looking for energy efficiency without extensive maintenance.
Are REHAU Windows Secure?
Thermal performance isn’t the only consideration when replacing windows.
Security is also important.
Modern REHAU window systems can be combined with suitable multi-point locking systems, security hardware and appropriate glazing specifications.
The exact level of security depends on the complete window configuration and hardware selected.
Homeowners should therefore ask their installer about the security specification rather than assuming every REHAU window has exactly the same performance.
How Much Do REHAU Windows Cost in the UK?
The cost of REHAU windows depends on several factors.
These include:
- Window size
- Number of windows
- REHAU profile/system
- Installation
- Double or triple glazing
- Glass specification
- Window style
- Property access
- Colour
- Hardware
- Removal of existing windows
As a result, there is no single fixed REHAU windows price that applies to every property.
A small replacement casement window will cost considerably less than a large bay window or a complete house replacement project.
For an accurate price, a professional survey is recommended.
Are REHAU Windows Worth It?
For homeowners looking for energy efficient uPVC windows, REHAU can be a strong option.
The combination of modern uPVC profiles, energy-efficient glazing and quality installation can provide:
- Better thermal insulation
- Reduced draughts
- Improved indoor comfort
- Low maintenance
- Modern security
- Long-term durability
- Improved appearance
However, the most important thing is to compare the specification of the complete window rather than choosing a product based only on the manufacturer’s name.
How to Choose Energy Efficient Replacement Windows
If you’re replacing windows specifically to improve energy efficiency, ask your installer these questions:
1. What is the complete Uw-value?
Don’t just ask for the glass U-value.
Ask for the whole-window Uw-value.
2. What glazing is included?
3. Is the window double or triple glazed?
4. Is installation included?
5. What guarantee is provided?
6. Is the installer experienced?
Why Choose Daylight Glazing for REHAU uPVC Windows?
At Daylight Glazing, we help UK homeowners choose windows based on their property’s requirements, design and performance needs.
Whether you’re replacing old windows, renovating a period property or upgrading a modern home, we can discuss suitable uPVC and aluminium window options.
Our window solutions can be specified around factors such as:
- Energy efficiency
- Glazing requirements
- Security
- Style
- Colour
- Property design
- Budget
We provide bespoke window solutions across London, Hertfordshire, Middlesex and surrounding areas, with options for supply-only and supply-and-fit projects.
If you’re considering REHAU windows for your home, we are the best installer of rehau windows which help you understand the available options and provide a quotation based on your actual window sizes and requirements.
Conclusion: Are REHAU Windows Energy Efficient?
Yes, modern REHAU windows can be highly energy efficient.
Their performance comes from the combination of an insulating uPVC profile, quality seals and appropriately specified double or triple glazing.
However, the best way to compare windows is to look beyond the brand name.
Check the complete Uw-value, glazing specification, frame design and installation quality before making your decision.
For homeowners looking for energy efficient replacement windows in the UK, modern REHAU uPVC windows can provide an effective combination of thermal performance, low maintenance, security and everyday practicality.
If you’re planning to replace your windows, speak to Daylight Glazing about your requirements and find out which window specification is right for your property.