The Benefits of Using Low-emissivity Bricks in Cold Climate Constructions

Understanding Low-Emissivity Bricks: A Thermal Innovation

In cold climate regions, the selection of building materials directly determines energy performance, occupant comfort, and long-term structural health. Traditional masonry often acts as a thermal bridge, drawing heat out of the building and increasing heating loads. Low-emissivity (low‑e) bricks address this weakness by incorporating a microscopically thin coating that selectively controls infrared radiation. Unlike standard bricks that absorb and re‑radiate heat away, low‑e bricks reflect a significant portion of radiant energy back into the interior.

Low‑e bricks are manufactured by applying a metallic oxide layer—commonly silver or tin oxide—to the brick surface during production. This coating is engineered to have low emissivity (typically below 0.2), meaning it emits very little thermal radiation compared to untreated clay or concrete. Result: less heat escapes through the wall assembly, and the brick itself stays closer to room temperature even when outdoor temperatures drop below freezing.

This technology builds on proven low‑e coatings used in windows for decades. Applying it to bricks provides a durable, opaque, and thermally efficient envelope component that works in concert with cavity insulation and air‑tightness strategies. Builders in Scandinavia, Canada, and northern U.S. states have begun specifying low‑e bricks for both residential and commercial projects.

How Low‑e Bricks Improve Thermal Performance in Cold Climates

Radiant Heat Control

Heat transfer through a wall occurs by conduction, convection, and radiation. In cold weather, the interior surface of a wall is warmer than the exterior surface, creating a temperature gradient. Standard bricks convect and conduct heat efficiently, but a large portion of heat loss is radiant: warm objects and surfaces inside the building emit infrared waves that strike the brick and are absorbed. Low‑e coatings interrupt this process by reflecting long‑wave infrared back into the living space. The result is a higher mean radiant temperature for the interior, which allows occupants to feel comfortable at lower thermostat settings—directly reducing energy consumption.

Reducing Thermal Bridging

Masonry walls, even when cavity insulated, suffer from thermal bridging at mortar joints, ties, and brick protrusions. Low‑e bricks cannot eliminate bridging entirely, but their lower emissivity reduces the surface temperature difference across the brick itself. When combined with continuous insulation (CI) on the exterior or interior, the overall assembly achieves better effective R‑values. Some manufacturers now produce low‑e bricks with integrated insulating cores or aerogel fills, further minimizing thermal bridging.

Condensation Mitigation

Condensation forms when warm, humid indoor air contacts a cold surface. In conventional brick walls, the interior face can drop below dew point during severe cold snaps, leading to moisture accumulation, mold, and material degradation. Because low‑e bricks keep the interior surface warmer, the risk of condensation is significantly reduced. This effect is especially valuable in bathrooms, kitchens, and buildings with high indoor humidity or tight vapor‑retarding construction.

Key Advantages of Low‑Emissivity Bricks for Cold‑Climate Construction

Enhanced Thermal Insulation: Low‑e bricks can increase the effective R‑value of a masonry wall by 30–50% compared to uncoated brick of the same thickness, depending on the coating quality and assembly design.
Improved Indoor Comfort: By raising the interior surface temperature, low‑e bricks reduce drafts and cold spots, creating a more uniform thermal environment without over‑sizing heating systems.
Energy Efficiency: Buildings constructed with low‑e bricks consistently achieve lower peak heating loads, contributing to reduced HVAC equipment size and operational costs. The technology aligns with net‑zero energy and passive house criteria.
Durability Under Extreme Freeze‑Thaw Cycles: The coating is bonded at high temperature and resists spalling, salt scaling, and UV degradation. Many low‑e brick products carry freeze‑thaw resistance ratings exceeding 300 cycles, suitable for Alaskan or Siberian winters.
Reduced Condensation and Mold Risk: Warmer interior surfaces keep the wall cavity drier, preserving insulation performance and preventing biological growth.
Low Maintenance: The coating does not require reapplying, pressure washing, or special care beyond standard masonry cleaning.

Comparing Low‑e Bricks to Other Insulating Materials

Low‑e vs. Insulated Concrete Forms (ICFs)

ICFs provide high continuous insulation but rely on expanded polystyrene (EPS) or extruded polystyrene (XPS) foam, which can be vulnerable to pest infiltration and require careful interior finishing to avoid thermal bypass. Low‑e bricks offer a more traditional aesthetic, better vapor permeability when needed, and no reliance on foam plastics. However, ICFs generally achieve higher overall R‑values per inch of wall thickness.

Low‑e vs. Exterior Insulation Finish Systems (EIFS)

EIFS cladding offers excellent continuous insulation with a synthetic coating, but it can be less impact‑resistant and more challenging to repair. Low‑e brick walls are inherently durable, fire‑resistant, and compatible with standard masonry ties and brickslips. Both systems can be combined, using low‑e bricks as the outermost veneer over an insulated backup wall to maximize thermal performance and weather resilience.

Low‑e vs. Standard Clay Brick with Cavity Insulation

Standard brick walls rely entirely on cavity insulation and air gaps. Even with high‑quality insulation, the brick itself remains cold and acts as a radiative heat sink. Low‑e bricks directly reduce that radiative loss, often enabling a thinner wall assembly to achieve the same thermal performance. In retrofit projects, applying a low‑e coating to existing brick (via factory‑fabricated panels or in‑situ spray coatings) can upgrade U‑values without removing the facade.

Implementation Guidance for Architects and Builders

Selecting the Right Low‑e Brick Product

Not all low‑e bricks perform identically. Key specifications to evaluate:

Emissivity value – Look for products with emissivity ≤ 0.2 (ideally 0.10–0.15).
Solar heat gain coefficient (SHGC) – In cold climates, a moderate SHGC can provide passive solar heating benefits during winter. Balance with summer overheating if applicable.
Freeze‑thaw rating – Ensure the brick meets ASTM C666 or equivalent for your region’s expected freeze‑thaw cycles.
Color and texture – Low‑e coatings can be applied to most brick colors without altering the appearance significantly, but some dark finishes may absorb more solar radiation. Consult manufacturers for preferred options.

Designing the Wall Assembly

Optimal performance requires attention to the entire wall stack‑up:

Structural backup – Concrete masonry units (CMU), wood framing, or steel studs with semi‑rigid mineral‑wool insulation.
Air‑barrier continuity – A properly taped or liquid‑applied air barrier prevents convective heat loss and moisture migration.
Continuous insulation (CI) – Even with low‑e bricks, adding CI (mineral wool, polyisocyanurate, or EPS) on the exterior or interior boosts overall R‑value and reduces thermal bridging further.
Low‑e brick veneer – Install with a 1‑inch drainage cavity (or per manufacturer) to allow moisture evacuation and pressure equalization. The low‑e coating remains effective regardless of the cavity depth.
Flashing and weep holes – Standard details apply; low‑e bricks do not require special flashing beyond corrosion‑resistant materials.

Installation Best Practices

Handle with care: Avoid scratching or abrading the coating. Use non‑abrasive mortar and soft brushes for cleanup.
Control thermal bridges at ties: Use stainless‑steel or hot‑dipped galvanized brick ties with thermal breaks (e.g., wire ties with plastic clips).
Coordinate with other windows and doors: Low‑e bricks adjacent to low‑e windows create a synergistic envelope with consistent radiant behavior.
Test mock‑ups: Before full‑scale installation, construct a mock‑up wall to verify U‑value and moisture performance under local climate conditions.

Case Studies in Cold‑Climate Construction

Residential Development in Fairbanks, Alaska

A four‑unit townhouse project used low‑e bricks (emissivity 0.12) combined with 4 inches of continuous mineral‑wool exterior insulation. Blower‑door tests showed airtightness at 1.2 ACH₅₀, and the measured whole‑wall U‑value was 0.14 BTU/hr·ft²·°F—a 40% improvement over the local code baseline. Occupants reported no cold drafts even during a two‑week period of −40°F.

Public School in Rovaniemi, Finland

Architects specified low‑e bricks for a new 3,500 m² school building to meet the Finnish energy class A requirements. The bricks contributed to a heating energy demand of just 52 kWh/m²/year, beating the national requirement by 18%. The warm interior wall surfaces reduced the need for baseboard heaters, and condensation‑related maintenance calls dropped to zero in the first three years.

Environmental and Life‑Cycle Benefits

Low‑e bricks are manufactured using the same raw materials and kiln processes as standard bricks, with an additional coating step. The coating adds approximately 5–10% to the embodied energy of the brick, but the operational energy savings typically offset that investment within two heating seasons. Over a 50‑year building life, low‑e brick assemblies can reduce total energy consumption by 25% or more compared to uncoated brick walls, lowering carbon emissions proportionally.

Furthermore, because low‑e bricks reduce the need for oversized HVAC equipment and minimize condensation‑related repairs, they contribute to longer service intervals and fewer material replacements. Many brick manufacturers now offer take‑back programs for recycling low‑e brick waste into aggregate or new brick bodies, supporting circular economy goals.

Future Innovations in Low‑e Masonry

Research is underway to develop dynamic low‑e coatings that can switch between low and high emissivity based on temperature (thermochromic) or electrical signals (electrochromic). Such bricks could automatically reflect heat during winter and allow night‑sky radiative cooling during summer, further optimizing energy balance. Another promising direction is the integration of phase‑change materials (PCMs) into low‑e brick cavities, storing thermal energy and releasing it when temperatures drop.

For now, static low‑e bricks remain a cost‑effective, proven technology that dramatically improves envelope performance in cold climates without sacrificing the aesthetics or durability of traditional masonry.

Conclusion

Low‑emissivity bricks represent a practical, high‑impact upgrade for cold‑climate construction. By reflecting infrared radiation, they reduce heat loss, improve comfort, and lower energy costs while mitigating condensation and extending building longevity. Whether used in new builds or retrofits, these bricks integrate seamlessly with modern insulation strategies and outperform uncoated masonry in every thermal metric. As building codes tighten and energy costs rise, low‑e bricks offer a robust solution that architects, builders, and homeowners can confidently adopt.