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Insulation and Deep Retrofit

Today, sustainability is no longer a trend. This turn to sustainable living by the public is no longer simply increasing the value of a home but an acknowledgment of climate change and the critical importance of protecting the environment. With the support from the government, rebates, and other initiatives for homeowners and the technological advancements made, sustainable strategies for homes make it more available, affordable, and easy for the masses.

The SEAI grants offered in Ireland are given to homes that have achieved a minimum B2 Building Energy Rating (BER).

One of the most cost-efficient ways to achieve an energy-efficient home, is insulation through deep retrofitting. However, the fabric first approach, such as triple-glazed windows, attic insulation of 300mm, solar photovoltaic installation, airtight membranes, and door upgrades, should work along with your deep energy retrofit.

It is important to note that a home will need insulation in different sections. The degree of impact of insulation installation will be dependent on the type of dwelling, whether it be a dormer, semi-detached, or detached.

Importance of Proper Insulation of Homes

When it comes to lowering your home's energy expenses and consumption, insulation is crucial. There will be a significant saving on heating bills and a reduction on your household's carbon footprint.

Benefits of insulation:

  • It saves non-renewable resources and minimizes greenhouse gas emissions by using less energy to heat or cool.

  • It lowers the cost of heating and cooling by more than 40%;

  • In around five to six years, it pays for itself;

  • Acoustic insulation is a property of most thermal insulation materials.

  • Condensation on walls and ceilings is usually eliminated.

Aside from the benefits mentioned above, an intervention sconcludes that insulation retrofitting significantly reduced HBP and was more beneficial for lowering the morning HSBP of hypertensive patients. Hypertension is the main cause of cardiovascular disease and the leading cause of death worldwide. (source:

In a review of housing-related health issues, the World Health Organization (WHO) identified cold homes as one of the major housing problems that need to be addressed to protect peoples' health. It notes that retrofitting insulation in homes can improve health outcomes and recommends measures to warm homes to a minimum of 18oC, and possibly more for older people and those with chronic conditions. (Source:

Three General Types of Insulation

Internal Wall Insulation. Also termed dry lining is where an extra layer of insulation is installed inside a wall. There are insulated boards that are structured to have vapor barrier and plasterboard, which can be installed on solid, cavity, or timber frame walls.



Reduce the rate of heat transfer from room to room and esxape through the external wall

Reduces internal room space

Serve as a sound barrier or damper

Removal of the need to renovate other architectural and structural elements

Generally, an affordable option that reduces energy consumption

External wall insulation. Imagine it as a continuous layer wrapped around your building's outer surface. The insulation covers a special render (plasterwork) made to withstand weather conditions. Usually, you'll have a mesh embedded to strengthen the insulation layer structurally.



Heat loss is reduced

It can be a costly project

Looks great from the outside with good quality render, giving the home a new look.

May require cavity insulation if the walls have a cavity, to prevent thermal looping.

Prevents mould build-up when properly installed

Cavity Wall Insulation. As the name implies, cavity wall insulation is used for homes with cavity walls. Homes built after the 1980’s are likely to have insulated cavities, or if a brick wall is more than 260mm thick, it probably has a cavity. However, it is best to get an expert to determine if your home has a cavity wall.



Prevents moisture build-up as it keeps the interior dry from the rain

Subpar installation can cause major problems such as thermal looping and mould build-up

Provides an air film that can act as an extra layer of insulation to the building preventing thermal bridging since materials are no longer in direct contact with each other

What is thermal looping?

Simply put, when air gaps are left between the insulation and the structure, such as partially filled hollow walls, thermal looping develops. Warm air rises on one side of the loop, while cold air descends on the other in a continuous cycle, which causes air movement. Thermal looping reduces insulation performance greatly, but it can be avoided if insulation is put appropriately.

Thermal looping in cavity walls can be fully prevented by filling the cavity with insulation and ensuring that there are no air spaces between the inner and outer leaves. Thermal looping in the attic can be avoided by firmly fitting attic and roof insulation between the rafters or joists and keeping the insulation uncompressed. Consider installing an insulated attic flooring system if you need more storage space in your attic.


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