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What is Retrofit?

Retrofitting is a specialised step-by-step construction to an existing building to make it more energy-efficient and comfortable for the occupants. It consists of some or all the following: insulation, airtightness improvement, new and improved windows and doors, new or improved heating system (most commonly an air source heat pump) and a ventilation system. All these elements can significantly change the external envelope of a dwelling and radically change the ventilation of the dwelling. Without an adequate ventilation strategy, moisture and indoor pollutants can develop which can cause severe implications to the health and well-being of the building and the occupants.




In traditional retrofit buildings, where any insulation or air-tightness measures are put in place, the existing ventilation is deemed inadequate. The existing ventilation must be improved to meet current building regulations. If a good level of airtightness is achieved (under 5m3/m2/hr @ 50Pa), then a continuous mechanical ventilation system must be installed. This requires a competent design, installation, commissioning and validation to ensure adequate air quality within the property. If ventilation is not considered during the renovation stages of a retrofit project – condensation and eventually mould could develop.

“As the relations between dampness, microbial exposure, and health etc cannot be quantified precisely, no quantitative health-based guideline values or thresholds can be recommended for acceptable levels of contamination with micro-organisms. Instead, it is recommended that dampness and mould-related problems be prevented. When they occur, they should be remediated because they increase the risk of hazardous exposure to microbes and chemicals.” – (WHO 2009)


Types of Retrofitting Models

Deep Retrofit

A deep retrofit can be commonly known as an energy conservation measure in an existing building. This can also lead to a comprehensive advancement in the building’s performance. An objective of a deep retrofit is to reduce the building’s onsite energy use by 50% compared to the “control” energy use. This can be calculated using utility bill analysis.

A One-Stop-Shop

A one-stop shop is a whole-house solution. It merges a range of energy measures carried out in a planned installation. Together these elements ensure an energy-efficient, low-carbon, and healthy home. They design your home’s energy solutions and attend to all the key stages, from tender through to payment of grant funding. To make certain that you are receiving the best quality retrofit, they engage with leading and established contractors.

List of One-Stop-Shops 


Do you have any signs of dampness/condensation or mould?


Why Ventilate?

Due to the new energy and acoustic requirements for dwellings, new constructions and renovated buildings are now basically an envelope with reinforced insulation and sealing, while older buildings are generally ‘over-ventilated’ due to leaky windows and outside walls.

The need to replace insulation, windows, and doors when retrofitting older buildings, has led to a decrease in air leakage. To overcome, future problems, it is necessary to recreate a ventilation circuit to ensure healthy internal air quality (IQA). Without ventilation, moisture levels, air pollutants, and VOCS build up, causing deterioration to the structure and finishes of the building, in turn putting the occupants’ health at risk.


Ways to Ventilate

There are different types of ventilation choosing one can be difficult. It is important to research a ventilation system that meets Irish regulations and works best within your home. It is important to know the overall cost of the system. This includes the initial cost of the system, installation, running costs and maintenance. Another factor that is important to consider commissioning. A system needs to be commissioned by a certified third-party validator, to ensure that it is meeting the regulations and working accordingly.



Mechanical Ventilation with Heat Recover, (MVHR) removes the warm moist air within your home (Kitchens, bathrooms, toilets, office areas) and at the same time supplies filtered pre-warmed air to your bedrooms and living areas.
It reduces the heat load in your home, giving a fresh and healthy house while also reducing heating costs. Wolf MVHR units are built to the highest standards and carry Passive House Certification.


We at Aereco combine the Wolf Units with a manifold air distribution system designed to optimise the MVHR units’ efficiency and comfort. It leads to a quiet and long-life system. We pride ourselves on our dedication to positive outcomes, and expert teams in the field. Our Aereco Quality Standard from design to commissioning ensure ventilation that works.

Click here to find out more about MVHR




Demand controlled ventilation is a way of looking at ventilating buildings that is a little different. Instead of there being a fixed rate of air exchange for a building or room based on a best guess, Demand Controlled Ventilation (DCV) measures the air quality and adjusts the rate of air exchange minute by minute, room by room, based on actual need.

Click here to find out more about DCV




WHO. (2009). WHO Guidelines for Indoor Air Quality: Dampness and
Mould https://www.cdc.gov/mold/pdfs/summary-of-2009-WHO-Guidelines-for-Indoor-Air-Quality-Dampness-and-Mould_508.pdf


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