What we do

External wall insulation

By creating a protective layer around your home, external wall insulation acts as a barrier against heat loss.

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Warmer home in the winter
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Cooler home in the summer
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Increase in property value
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Improved aesthetics
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Loads better for the environment
Rockwarm external wall insulation
Rockwarm external wall insulation
Rockwarm external wall insulation
Rockwarm external wall insulation
Rockwarm external wall insulation
Rockwarm external wall insulation
Rockwarm external wall insulation
Rockwarm external wall insulation
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BBA Approved

The British Board of Agrément for industry safety.

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What is external wall insulation?

External wall insulation involves adding a layer of insulation material to the outside of a building's walls (like wrapping a building in a warm blanket). The insulation boards are then covered with a special mesh and several layers of render  to protect it from the weather and to improve the building's appearance.

The main goal is to retain the heat inside your home for longer during colder months and make the home cooler during warmer months, making the building more energy-efficient and comfortable to live in. This can help reduce energy bills and also decrease the building's carbon footprint by reducing the need for heating and cooling.

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What are the benefits?

External wall insulation offers several benefits for homes, particularly given the UK's climate and energy efficiency standards. EWI provides a comprehensive solution to improve energy efficiency, comfort, and the longevity of homes in the UK.

Thermal efficiency

External wall insulation significantly reduces heat loss through walls, which are one of the biggest sources of energy loss in buildings. By wrapping the exterior in a layer of insulation, it creates a continuous thermal barrier. This improvement leads to more stable indoor temperatures, reduced need for heating and cooling, and lower energy bills.

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Energy savings

With better thermal retention and efficiency, buildings require less energy to maintain comfortable living conditions. This reduction in energy usage not only lowers utility costs but also decreases the building's carbon footprint, contributing to environmental conservation.

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Improved aesthetics

EWI provides an opportunity to refurbish the external appearance of a building. It can be finished with a variety of materials and colours, offering aesthetic improvements that can increase property value and curb appeal.

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Property value

The improved aesthetic appeal combined with enhanced energy efficiency can increase a property's marketability and value. Prospective buyers or tenants often value the upgraded appearance and energy savings, making properties with EWI more attractive in the property market.

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Environmental impact

Beyond reducing operational energy use, EWI also lowers the environmental impact during the heating and cooling phases of a building's life cycle. This contributes to sustainability goals by reducing greenhouse gas emissions.

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Durability & protection

EWI protects the existing external walls from weather impacts, such as rain, frost, and thermal stress from fluctuations in temperature. This protection can extend the life of the building materials, reducing maintenance costs and preserving the structure.

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Thermal efficiency

External wall insulation (EWI) is highly thermally efficient due to its ability to encapsulate the entire exterior of a building with a continuous layer of insulation. This approach effectively minimises thermal bridging and maximises the building's overall insulation properties. Here's a detailed look at why EWI is so effective at improving thermal efficiency:

Continuous insulation layer

Unlike internal insulation or cavity wall insulation, external wall insulation covers the entire outer surface, including all potential thermal bridges like corners and junctions. This continuous layer eliminates cold spots and ensures that heat is retained inside the building more effectively.

Reduction in thermal bridging

Thermal bridges are areas where heat flows more readily through the structure, such as around windows, doors, and where floors meet external walls. By applying insulation on the exterior, these bridges are covered, significantly reducing heat loss. This uniform barrier helps maintain consistent internal temperatures and reduces the energy required to heat or cool the space.

Stabilises internal temperatures

By insulating the exterior walls, the insulation also helps to buffer the internal environment from external temperature fluctuations. This means that in winter, it keeps the cold out and the heat in, and in summer, it does the opposite by reflecting heat away and keeping interiors cool. This stabilisation requires less energy input from heating and cooling systems to maintain comfortable conditions.

Enhances wall thermal mass

External wall insulation can help capitalise on the thermal mass of the building’s walls. The walls absorb heat during the day and release it slowly when temperatures drop, helping to stabilise temperature over the day and night cycles. Insulation on the outside means that this heat is not lost to the outside but is instead released back into the building, making heating systems more efficient.

Moisture management

Effective moisture management contributes to thermal efficiency. By keeping the wall dry, EWI reduces the thermal conductivity of the wall material (wet materials transfer heat more readily than dry materials). Also, most EWI systems are designed to be breathable, allowing moisture from inside the building to escape, which helps in maintaining the insulation's effectiveness and the structural integrity of the wall.

Long-term performance

External wall insulation materials are designed to be durable and resistant to environmental impacts. This longevity ensures that the thermal efficiency is maintained over many years, reducing the need for repairs and upgrades and ensuring consistent energy savings.

Overall, external wall insulation is thermally efficient because it creates a robust, uniform barrier against heat transfer, significantly reducing energy costs and enhancing the comfort inside a building. Its ability to cover and insulate the entire exterior of a structure makes it one of the most effective forms of building insulation available.

Energy savings

External wall insulation (EWI) is a highly effective energy-saving solution for several compelling reasons:

Reduced heat loss and gain

The primary function of EWI is to minimise heat transfer between the interior of a building and the external environment. By wrapping the building in a continuous insulating layer, EWI significantly reduces heat loss in cold months and heat gain during warm months. This leads to less energy being required to maintain a comfortable indoor temperature, which is directly reflected in lower heating and cooling costs.

Improved energy efficiency

EWI increases the overall thermal efficiency of the building envelope (the barrier between conditioned and unconditioned space). This improvement means that HVAC systems (heating, ventilation, and air conditioning) need to work less to achieve and maintain desired temperatures, which conserves energy and reduces operating costs.

Enhanced thermal mass regulation

Insulating the exterior of the walls helps to capitalise on the building's thermal mass, which is the ability of a material to absorb and store heat energy. During the day, thermal mass can absorb heat that would otherwise enter the living space, releasing it slowly when the temperature drops. In insulated buildings, this heat is not lost to the outside but helps to warm the building when temperatures fall, thus reducing heating demands.

Consistent indoor climate

By stabilising indoor temperatures and reducing the impact of external temperature fluctuations, EWI makes indoor spaces more comfortable. This stability means that heating and cooling systems require less frequent cycling on and off, which not only saves energy but also reduces wear and tear on the systems, extending their lifespan.

Reduced carbon footprint

By decreasing the amount of energy needed for heating and cooling, EWI also lowers greenhouse gas emissions associated with energy production. This reduction contributes to environmental sustainability and can help building owners meet regulatory requirements for energy efficiency and emissions.

Long-term cost savings

Although the initial installation of EWI involves some investment, the long-term savings on energy bills can be substantial. These savings, combined with potential increases in property value and eligibility for energy efficiency grants or rebates, make EWI a financially viable energy-saving solution.

In conclusion, external wall insulation is an effective solution for saving energy because it tackles the fundamental issue of heat loss and gain through the building's exterior, leading to reduced energy demand, lower utility costs, and a more comfortable, sustainable living or working environment.

Improved aesthetics

External wall insulation (EWI) can significantly improve the appearance of a home, providing both aesthetic and functional upgrades. Here’s how EWI enhances a building's exterior:

Modernisation and aesthetic enhancement

When applying external wall insulation, the final coat is a render or cladding that can be finished in various textures and colours. This provides an opportunity to completely refresh and update the external appearance of a building. Whether you're aiming for a smooth, contemporary finish or a more traditional look, EWI offers a range of aesthetic possibilities that can dramatically improve curb appeal.

Uniform appearance

Older homes, in particular, can suffer from patchy brickwork, discolouration, and weathering. EWI covers any imperfections in the existing façade and provides a uniform, clean look that rejuvenates the building’s exterior. This uniformity can make an old building look almost new, enhancing its visual appeal and potentially increasing its market value.

Choice of finishes

The variety of finishes available with EWI systems allows for customisation according to homeowner preferences or local architectural styles. Common finishes include various types of render (smooth, textured, or painted in different colours), brick slips that mimic the look of real brick, and even stone or tile effects. These choices mean that insulation upgrades can be tailored to blend seamlessly with the building's surroundings or stand out as a statement piece.

Protection from elements

EWI not only improves the look of a home but also protects the structure from weather-related wear and tear, such as dampness and temperature fluctuations. The new outer layer shields the walls from rain, frost, and sun, preventing deterioration and keeping the building looking better for longer.

Long-lasting durability

The materials used in EWI are designed to be durable and resistant to environmental conditions. This durability means that the building maintains its improved appearance over time with minimal maintenance required, unlike untreated exteriors that might need regular repainting or repairs.

In summary, external wall insulation provides a practical solution for enhancing a home's energy efficiency while simultaneously upgrading its external appearance. This dual benefit makes it an appealing choice for homeowners looking to improve both the function and form of their properties.

Property value

External wall insulation (EWI) can significantly increase the value of a property through several key enhancements:

Energy efficiency

One of the most impactful ways EWI increases property value is by significantly improving the building's energy efficiency. This improvement leads to lower heating and cooling costs, which is a highly attractive feature for prospective buyers or tenants. Energy-efficient homes are not only more comfortable and affordable to maintain but also tend to have higher market values due to their reduced environmental impact and future-proofing against rising energy prices.

Enhanced aesthetic appeal

As mentioned earlier, EWI can dramatically improve the external appearance of a building. Whether through modern renders, traditional brick slips, or other finishes, a refreshed facade can make an old building look like new. This visual upgrade enhances curb appeal, which is a critical factor in real estate valuation.

Improved comfort and indoor environment

The added insulation helps maintain a stable and comfortable indoor temperature, reducing drafts and cold spots. This improvement in the living environment is a key selling point, as comfort is a priority for most homeowners and tenants.

Reduced maintenance costs

EWI protects the exterior walls from weather and environmental damage, leading to reduced maintenance costs over time. This protection is a valuable asset, as it prolongs the lifespan of the building's structure and reduces the need for expensive repairs and upkeep, something potential buyers will find appealing.

Better building health

By preventing moisture penetration and managing condensation effectively, EWI reduces risks associated with damp and mould, which are significant detriments to both health and structural integrity. A healthier building environment is more attractive to buyers and can enhance the overall property value.

By addressing both aesthetic and functional aspects of a building, EWI makes properties more attractive to buyers and renters, leading to higher demand and potentially higher sale prices or rental income. This overall increase in property value is a compelling reason for homeowners and investors to consider installing external wall insulation.

Environmental impact

External wall insulation (EWI) has a significant positive impact on the environment by improving energy efficiency and reducing the overall carbon footprint of buildings. Here are the key environmental benefits of installing EWI:

Reduced energy consumption

The primary environmental benefit of EWI is its ability to dramatically reduce the amount of energy needed to heat and cool buildings. By insulating the exterior walls, EWI minimises heat loss in the winter and heat gain in the summer, which means heating and cooling systems require less energy to maintain comfortable indoor temperatures. Lower energy consumption directly translates to less reliance on fossil fuels and fewer emissions from power plants.

Lower greenhouse gas emissions

By decreasing the demand for energy, EWI helps reduce the emissions of greenhouse gases like carbon dioxide (CO2) and methane (CH4), which are major contributors to global warming and climate change. These reductions are crucial for meeting global environmental targets and for reducing the ecological footprint of residential and commercial buildings.

Enhanced building longevity

EWI protects the building fabric from external weather conditions, such as rain, frost, and temperature fluctuations. This protection helps to prolong the lifespan of the building materials and reduces the need for repairs and replacements. By extending the life of building materials, EWI contributes to reduced resource consumption and waste generation, as well as lower environmental impact associated with manufacturing, transporting, and installing new materials.

Improved air quality

Reduced dependence on heating and cooling systems means less combustion of fossil fuels, particularly in areas where electricity is generated from coal, oil, or gas. This not only lowers carbon emissions but also reduces air pollutants like sulphur dioxide (SO2) and nitrogen oxides (NOx), which are responsible for smog and acid rain.

Reduction in resource use

By decreasing the amount of energy required for heating and cooling, EWI indirectly reduces the extraction and processing of natural resources needed to produce that energy. This conservation of resources is essential for sustainable development.

Overall, the installation of external wall insulation represents a significant step towards more environmentally friendly living spaces. It supports the transition to a low-carbon economy, promotes healthier urban environments, and aligns with broader environmental objectives like reducing energy consumption and preserving natural resources.

Durability and protection

External wall insulation (EWI) not only enhances a building's energy efficiency but also significantly contributes to its durability and protection. Here’s how EWI provides these benefits:

Weather protection

EWI systems involve covering the external walls of a building with layers of insulating material and a protective render or cladding. This outer layer shields the walls from environmental stressors such as rain, snow, wind, and UV radiation. By protecting the building's structure from these elements, EWI helps prevent deterioration over time, including issues like cracking, spalling, or moisture ingress, which can weaken the building fabric.

Thermal stress reduction

Temperature fluctuations can cause the building materials to expand and contract, leading to thermal stress. Over time, this can create cracks and other structural damage. By regulating the temperature of the external walls, EWI minimizes these fluctuations, reducing the risk of thermal stress and prolonging the life of the building materials.

Moisture management

Properly installed EWI systems include components that manage moisture effectively. These systems can prevent rainwater penetration while allowing any moisture that does infiltrate or is generated inside the building to escape. This balance prevents the buildup of dampness and condensation within the wall structure, which can lead to mold growth and structural decay.

Enhanced structural integrity

By covering older or deteriorating wall surfaces, EWI can provide a new lease on life to the existing structure. It helps to stabilise and protect the walls, potentially correcting minor imperfections and preventing further damage.

The protective layer offered by EWI reduces the need for frequent maintenance and repairs that are typically required for exposed wall surfaces. This not only saves costs over the long term but also ensures that the building remains in good condition with less effort.

In summary, external wall insulation offers robust protection and increased durability to homes, safeguarding the structural integrity and extending the lifespan of the building while enhancing living conditions through improved thermal regulation and moisture management.