Understanding nZEB and Its Role in Modern Homes

In Ireland, where homes consume a significant portion of energy, it is crucial to understand what nZEB is and how it can revolutionize our approach to residential construction and energy efficiency. In this article, we’ll explore the concept of nZEB and how it aligns with our mission of sustainable and comfortable living.

What is nZEB?

Nearly Zero Energy Building, abbreviated as nZEB, is a building concept that sets an ambitious target for energy efficiency. It aims to achieve a balance between the energy a building consumes and the energy it produces from renewable sources.

The nZEB standard means that a building must have a very high energy performance. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources. This includes energy from renewable sources produced onsite or nearby

In simpler terms, nZEB is designed to minimize energy demand while maximizing the use of renewable energy sources, ultimately leading to a near-zero net energy consumption.

The NZEB standard will apply to all new buildings occupied after the 31st December 2020. For Public Sector bodies, the standard will apply to all new buildings owned and occupied by the 31st December 2018.

What are Benefits of nZEB?

All new homes will be nearly zero energy buildings (nZEB) and will have a typical building energy rating (BER) of A2. This is compared with the current A3 rating for new builds. New homes will be 70% more energy efficient and will emit 70% less carbon dioxide than 2005 performance levels.

A typical A-rated, 3 bedroom, semi-detached house is likely to be approximately €800 per annum cheaper to heat than a similar house built before 2005. Existing dwellings undergoing major renovations will be required to achieve a BER of B2 or equivalent.

Some of the key benefits of nZEB are:

• Reduced Carbon Emissions: By using renewable energy sources and minimizing energy consumption, nZEBs contribute to a substantial reduction in carbon dioxide emissions. This aligns with Ireland’s commitment to combat climate change.
• Cost Savings: While nZEBs may have higher upfront construction costs, the long-term savings on energy bills offset this investment. Homeowners can enjoy substantial cost savings over the lifetime of their homes.
• Improved Indoor Comfort: nZEBs are designed to maintain consistent indoor temperatures, reducing drafts and temperature fluctuations. This results in a more comfortable living environment year-round.
• Health Benefits: Enhanced indoor air quality in nZEBs promotes better health for occupants. Mechanical ventilation systems ensure a constant supply of fresh, filtered air, reducing the risk of respiratory issues and allergies.
• Compliance with Regulations: nZEBs align with Ireland’s building regulations and EU directives, ensuring that new constructions meet energy efficiency standards and sustainability goals.
• Increased Property Value: nZEB homes are more desirable in the real estate market due to their energy efficiency and lower operating costs. This can lead to higher property values and easier resale.
• Future-Proofing: As energy efficiency standards continue to evolve, nZEBs are well-positioned to meet future regulations, protecting homeowners from costly retrofitting and ensuring the longevity of their investments.

What are nZEB requirements of domestic new builds?

The requirements for Nearly Zero Energy Building (nZEB) for domestic new builds in Ireland are outlined in Part L of the Building Regulations.

For all new builds it is proposed that nZEB will be equivalent to a 25% improvement in energy performance on the 2011 building regulations. Key changes to part L for NZEB compliance include a maximum energy performance coefficient of 0.3, a maximum carbon performance of 0.35 and a renewable energy ratio of 20%.          

They should achieve a BER Rating of A2.

What are nZEB requirements of domestic renovations?

For existing buildings, major renovation is typically activated under the following circumstances, where the work affects greater than 25% surface area of the existing dwelling:

• External Wall Renovation, external or internal insulation
• External Wall & Window Renovation
• External Wall & Roof Renovation
• External Wall & Floor Renovation
• New Extension

Under NZEB rules, the entire property must be brought to BER B2 rating.

Key Components of nZEB Constructions

Superior Insulation

nZEB homes are built with exceptional insulation to minimize heat loss or gain, ensuring that indoor temperatures remain comfortable year-round.

Renewable Energy Sources

These buildings generate a substantial portion of their energy from renewable sources like solar panels, wind turbines, or heat pumps, thus reducing dependence on traditional energy sources.

Energy-Efficient Systems

From lighting to heating, nZEBs employ energy-efficient appliances and systems, including advanced heating and cooling solutions.

Airtight Construction

nZEBs are constructed with precision to eliminate air leakage, preserving the desired indoor temperature and saving energy.

Efficient Ventilation

Heat recovery ventilation systems, like those offered by Flynn Heat Recovery Systems, play a pivotal role in maintaining healthy indoor air quality and maximizing energy efficiency in nZEB homes.

The Role of Ventilation in nZEB

A healthy home is characterized by excellent air quality and a reduced risk of condensation. This becomes particularly significant as we embrace highly insulated and tightly sealed homes, which can inadvertently lead to insufficient ventilation and overheating issues.

The cornerstone of an NZEB home lies in striking the right balance between heating and cooling. As modern homes become increasingly airtight, the risk of overheating rises, making cooling measures equally crucial.

Although ventilation isn’t currently mandatory for NZEB constructions, it is strongly advised and could potentially become a future regulatory requirement.

In addition to ventilation, effective temperature management is essential, requiring heating in winter and cooling in summer. This is where heat recovery is integrated into the ventilation system. Heat recovery units capture and transfer the building’s warmth to the incoming fresh air. These units include a summer bypass feature, allowing them to draw in outside air directly and bypass the heat exchanger when the building reaches elevated temperatures, effectively preventing overheating. Overall, achieving low-energy homes must consider health and ventilation as inseparable components, especially in our drive towards energy-efficient, tightly sealed, and well-insulated dwellings.

We Are Your Partner in nZEB

nZEB represents the future of sustainable construction and renovation in Ireland. These standards aim to create homes that are not just energy-efficient but also comfortable and environmentally friendly.

Flynn Heat Recovery Systems is dedicated to providing innovative MVHR systems that align seamlessly with nZEB principles. Our range of products, including heat recovery systems and Mechanical Extract Ventilation (MEV) systems, offer homeowners and builders the means to achieve superior indoor air quality and energy efficiency.

By choosing our mechanical ventilation systems, you’re not just improving your home; you’re contributing to a greener, more sustainable future for Ireland.