What Are the Best Materials for Thermally Efficient Sash Windows

Sash windows are a great addition to houses due to their timeless charm. However, without the right materials, they can be major energy drains. So, it is important for property owners to carefully choose the right material for sash windows in their property.

Sash windows have always been a popular choice among architects. The windows look aesthetic and add a historic charm to the property. However, when it comes to your own home, choosing an aesthetic option isn’t enough.

The process is also about choosing an option that offers long-term benefits and energy efficiency. Picking the right materials plays an important role in energy efficiency, especially in places with a cool and damp climate like Northern Ireland. Poor quality material results in heat loss and increases utility bills.

On the flip side, thermally efficient sash windows trap the heat inside and keep the property warm, making these materials essential for sash windows in Northern Ireland and its surrounding areas.

In this blog, we will walk you through the different materials that are ideal for thermal efficiency in sash windows. From the best frame and glazing options, we will break down everything.

Why Thermal Efficiency Matters in Sash Windows

Sash windows were initially designed mainly for aesthetic purposes, and energy efficiency didn’t have much to do with it. This is why you will often find that old sash windows are single-glazed, leaky, and poor insulators.

However, this doesn’t match the changing living patterns of today, and also with houses situated in different terrains. For instance, if you take a house situated in Northern Ireland into consideration, then you will notice that most houses have heating systems that help in keeping the houses warm in Belfast and its surroundings.

But without thermally efficient windows like flush sash windows in Belfast, it becomes tough to keep the houses properly insulated. The windows fail to trap the heat inside, resulting in heat loss. Ultimately, this increases the property’s utility bills.

In 2024, the average energy bill in the Northern Ireland town, Belfast, was around £1,160.01. The amount is huge and might not be ideal for every household. So, energy-efficient windows pose as one of the best solutions to lower the utility bills.

Using thermally efficient windows results in a significant reduction in energy bills. However, that is not all. They also help in lowering one’s carbon footprint and condensation, and drafts. Thus, it makes them a better choice for every reason.

Best Materials for Thermally Efficient Sash Windows

When looking to install sash windows in Northern Ireland, the following materials are the best option.

Timber

This material is traditional, but it is also a sustainable choice. Sash windows made out of timber look aesthetically pleasing, a big reason why you would ideally find them in heritage properties.

Beyond their looks, they are also naturally insulating. But for that, property owners should keep them well-maintained. This material is also quite sustainable and easily repairable, making it a popular choice in many houses.

However, timber requires regular upkeep to maintain its quality and efficiency. On top of that, they are vulnerable to moisture and warping, which is why they aren’t ideal for homes near the coastal region.

Best for: Heritage properties and conservation areas

uPVC

This material is extremely low-maintenance and doesn’t require regular cleaning or maintenance. Other than that, the flush sash windows in Belfast are also quite affordable, require no maintenance like periodic painting, and last for more than a decade. This makes them a cost-effective option for property owners.

The best part about these windows is that they have excellent thermal efficiency. These ideally have low U-values that range between 1.2 and 1.6 W/m²K with the right glazing.

However, these windows may not work with periodic homes, which stops them from being perfect for all properties.

Best for: Modern homes, tight budgets, energy upgrades

Aluminium With Thermal Break

Sash windows made out of this material look sleek and have a modern appearance. These have a strong and slim frame, ideal for larger glazing. Thermally broken aluminium also plays a big role in improving insulation, which makes it a popular choice among property owners.

Moreover, these windows are also extremely durable and last for years with minimal maintenance. The low-maintenance aspect of these windows frees property owners from the endless cycle of spending a ton of time and money on fenestration maintenance.

But on the flip side, this material is way more expensive than uPVC and also lacks when it comes to insulation. So, consider these factors before making the choice.

Best for: Contemporary builds, urban settings

Best Glazing Options for Sash Windows

Here are a few glazing options that property owners can consider when choosing sash windows in Northern Ireland.

Double glazing

Also referred to as low-E coated, this is ideal for energy efficiency. This can help in increasing the energy efficiency of timber material sash windows by 40%.

Triple glazing

This is ideal for cold climates or passive homes, making them a popular choice in Northern Ireland. This glazing option lowers heat loss by 30%, which makes the windows more energy efficient.

Argon/krypton Gas-filled Units

Argon and krypton gas-filled units significantly reduce heat transfer. These gases enhance insulation, and they are inert, non-toxic, and odourless, making them ideal.

Material Selection Based on Home Type

Each home is different due to its structure, location, and other factors like what a property owner desires to achieve. This is why in this section, we present a simplified view regarding the material selection depending on the type of home.

Table: Sash Material as per Home Types

In Summation

Besides aesthetics, energy efficiency plays an important role in sash windows. This is especially important when choosing sash windows in Northern Ireland and its surrounding areas, as the region has a cool and damp climate, resulting in heat loss and high heating costs.

For thermally efficient sash windows, materials like engineered timber, uPVC, and aluminium with thermal breaks, paired with the right glazing, are the best. They make a big difference in comfort and cost savings.

However, the best choice depends on your home type, budget, and aesthetic needs. So, in the end, it’s all in your hands.

Thinking of upgrading your sash windows?

Understand which material for sash windows in Northern Ireland will work the best for your home. Get it installed by a professional.