How Energy Efficient Is Your Front Door?

We often think about windows when considering the energy efficiency of our homes, but the entrance door is an equally important part of the building envelope. A poorly insulated or poorly sealed front door can allow heat to escape, create cold draughts and make your home less comfortable.

So, how energy efficient should a front door be?

A high-performance entrance door should combine effective thermal insulation, a well-insulated frame, high-quality seals and, where glazing is used, energy-efficient glass. The overall performance of the complete door system is what matters- not simply the material it is made from. For homeowners building or renovating with energy efficiency in mind, choosing a high-performance entrance door can make a meaningful contribution to a more comfortable and energy-efficient home.

• A front door forms part of your home's thermal envelope and can affect overall energy efficiency.

• Look at the U-value of the complete door, rather than focusing on individual components.

• Insulated door panels, frames and effective seals all help reduce heat loss and draughts.

• Glazing can be energy efficient too, while bringing valuable natural light into your entrance.

• and can both deliver high levels of thermal performance when properly designed and insulated.

• High-performance entrance doors are particularly important in low-energy and Passivhaus homes.

There are several elements that determine the thermal performance of an entrance door.

1. Insulated Door Construction: The door panel itself needs to minimise heat transfer between the inside and outside of your home. High-performance entrance doors use carefully engineered, insulated constructions to reduce heat loss. Internorm's timber-aluminium entrance doors, for example, combine timber, thermal foam and aluminium in a multi-layered construction. This combination provides high levels of thermal insulation while also offering the durability of an external aluminium layer.

2. A Thermally Efficient Frame: The door sash is only part of the equation. The frame surrounding it can also influence the overall thermal performance. This is why it is important to consider the U-value of the complete door system, rather than simply looking at the insulation properties of the door panel.

3. Effective Gaskets: Even a highly insulated door can perform poorly if there are gaps around the frame or door sash. High-quality gaskets help minimise air leakage and draughts while also improving protection against wind and weather. This is particularly important in winter, when cold air entering around an external door can noticeably affect comfort.

U-value measures how easily heat passes through a building element. The lower the U-value, the better the thermal insulation. For entrance doors, look for the U-value of the complete door, expressed in W/(m²K). This allows you to make a more meaningful comparison between different products.

Internorm entrance doors are engineered for high thermal performance. For example, the HT 410 timber-aluminium entrance door can achieve a U-value of up to 0.58 W/(m²K), while the current aluminium range includes systems achieving U-values of 0.75 W/(m²K) and below, depending on the model.

The important point: when comparing entrance doors, don't simply ask whether a door is "energy efficient". Ask for its tested U-value and check that you are comparing like-for-like specifications.

Not necessarily. Glazing can be an important part of an entrance door, bringing natural daylight into a hallway or entrance area. The thermal performance of the glass should, however, be considered alongside that of the door itself.

Modern high-performance glazing can provide excellent insulation while allowing homeowners to introduce light without making a major compromise in thermal performance. Side lights and fanlights can also be incorporated where additional daylight is desired.

For an energy-efficient home, the aim is therefore not necessarily to avoid glazing, but to choose the right glazing and consider the performance of the complete entrance system.

Aluminium has traditionally been associated with heat transfer, but modern thermally insulated aluminium entrance doors are very different from older aluminium systems. Today's high-performance aluminium doors incorporate advanced insulation within the frame and door construction to reduce heat transfer.

includes systems such as the AT 530 and AT 540, which achieve U-values down to 0.75 and 0.78 W/(m²K) respectively.

This means you don't have to sacrifice thermal performance to achieve the clean, contemporary appearance and durability of an aluminium entrance door.

Not necessarily. offer another approach to high thermal performance. The combination of natural timber, thermal insulation and an external aluminium layer provides excellent insulation while protecting the door from the elements.

Internorm's HT 410, for example, has a construction depth of up to 121 mm and achieves a U-value of up to 0.58 W/(m²K). The timber interior also provides a warm, natural aesthetic that can be coordinated with timber-aluminium windows elsewhere in the home. So it comes down to your personal preference.

In a high-performance home, every part of the building envelope needs to work together. Windows, doors, walls, roofs and floors all contribute to the overall thermal performance of the building. An inefficient entrance door can therefore undermine the performance achieved elsewhere.

For this reason, high-performance entrance doors are particularly important in Passivhaus and low-energy projects, where minimising heat loss and maintaining a comfortable internal environment are key priorities.

Internorm's timber-aluminium and aluminium entrance doors are ideally suited for low-energy and Passivhaus projects due to their low u-values.

If your existing entrance feels cold or draughty, replacing it with a modern, high-performance door can be one part of improving the thermal performance of your home. When choosing a replacement, look beyond appearance and consider:

• Whole-door U-value

• Insulation within the door construction

• Frame performance

• Quality of seals

• Glazing specification

• Professional installation

A beautiful front door should do more than create a welcoming entrance. It should help keep your home warm in winter, comfortable throughout the year and protected from draughts and the elements. At the same time, if should keep your home and belongings safe and secure. Internorm entrance doors offer a range of enhanced security features to ensure that burglars stay out.

• What is a good U-value for an entrance door?

  The lower the U-value, the better the thermal insulation. However, U-values should always be compared on a like-for-like basis and should refer to the complete door system.

• Are aluminium front doors energy efficient?

  Yes. Modern thermally insulated aluminium entrance doors can provide high levels of thermal performance. The exact U-value depends on the door system and specification.

• Are timber-aluminium doors more energy efficient than aluminium doors?

  Not necessarily. Both materials can provide excellent thermal performance when properly designed and insulated. The specification and construction of the complete door system are more important than the material alone.

• Can a new front door reduce draughts?

  Yes. A modern, well-installed entrance door with effective gaskets can significantly reduce air leakage and draughts compared with an older or poorly sealed door.

• What should I look for when buying an energy-efficient front door?

  Look at the whole-door U-value, insulation, frame construction, gaskets, glazing and installation - not simply the material or appearance of the door.

Why not They will have some examples of what is available and can advise on the best front door for your home.