New Build Energy Solutions Ireland: NZEB Compliance, Heat Pumps, Solar & Ventilation

High energy performance is the key to all new residential development in Ireland since all new housing and apartment schemes must meet increasingly demanding environmental requirements, and the bar is only set to rise to zero emission standards in the coming years.

The standard that shapes today’s new homes is Nearly Zero Energy Building (NZEB), and achieving this certification requires careful design and planning of insulation, airtightness, heat pumps, solar PV, ventilation and heating controls from the earliest design stages so everything performs as one system.

For developers, that coordination requires controlling project costs, demonstrating compliance, sticking to construction schedules and managing multiple specialist suppliers on site. This guide explains what new-build energy solutions in Ireland involve, how the key systems fit together, and how to plan delivery across housing and apartment developments.

What Is NZEB and Why Is It Important in Ireland?

NZEB stands for Nearly Zero Energy Building. In practice, it means a home designed to need very little energy, with much of that remaining demand met by renewable sources. For Irish residential developments, NZEB is the baseline performance standard that every new house and apartment must achieve.

Why NZEB was introduced

NZEB originates from the EU Energy Performance of Buildings Directive, which required member states to raise the performance of new buildings to a nearly zero energy level. In Ireland, it supports national objectives to improve energy efficiency, reduce reliance on fossil fuels and cut carbon emissions from the built environment, which accounts for a significant share of national energy use.

The role of Part L

NZEB requirements for dwellings are set out in Part L of the Irish Building Regulations (Conservation of Fuel and Energy). SEAI describes the established requirements in terms of three measures: energy performance, carbon performance and renewable energy contribution. All three are assessed using DEAP, the Dwelling Energy Assessment Procedure.

Key areas that influence energy performance

• Building fabric and insulation: walls, roofs, floors, windows and doors must limit heat loss through high thermal performance.
• Airtightness and heat loss: uncontrolled air leakage and poorly detailed junctions can undermine an otherwise well-insulated building.
• Efficient heating and hot water: the heating system has a major influence on both primary energy use and carbon emissions.
• Ventilation: airtight homes need a planned ventilation strategy to protect air quality and control moisture.
• Renewable energy technologies: heat pumps and solar PV are commonly used to meet the renewable energy contribution.

BER assessments and compliance calculations

Compliance is demonstrated through energy performance calculations in DEAP, which also produce the dwelling’s Building Energy Rating (BER). Calculations are typically run at design stage to test the specification, then updated as built to confirm the final result.
Ireland introduced a revised BER scale during May 2026, including a new A0 category for zero-emission buildings. NZEB and zero-emission buildings are not the same standard. A home can be NZEB compliant without achieving A0.

An individual house allows a fairly self-contained energy strategy. A housing estate repeats similar house types, so getting the specification right early pays off across every unit. Apartment developments add further complexity, with shared plant, limited roof space and services running through multiple floors.Installing solar panels or a heat pump does not automatically mean a building complies with NZEB. Compliance depends on how the fabric, airtightness, heating, ventilation and renewables perform together in the DEAP assessment.

That is why compliance must be considered at design stage. Discovering a shortfall just before completion can force expensive late additions, redesigns or programme delays.

For a more detailed explanation of the standard, read our guide: What Does NZEB Mean and What Does It Require for Irish New Builds?

The Key Energy Systems Required for Modern New-Build Developments

No single system delivers an energy-efficient home. Modern new builds rely on several technologies working together, each with a distinct role. The table below summarises them before we look at each in turn.

Heat Pumps and Heating Systems

Heat pumps extract heat from the outside air, ground or water and transfer it into the home for space heating and hot water. Because they move heat rather than generate it by burning fuel, they deliver several units of heat for each unit of electricity used.

This efficiency, combined with their contribution to the renewable energy requirement, has made heat pumps the most common heating choice for new housing and apartment developments in Ireland.

Developers can choose between different approaches:
• Individual heat pumps serve a single dwelling, typically an air-to-water unit outside each house. This is the standard approach on housing estates and gives each homeowner direct control and simple billing.
• Shared or centralised solutions serve multiple units from common plant. These can suit apartment developments where external space for individual units is limited, but they require careful design of distribution, metering and maintenance arrangements.

Correct sizing, system design and commissioning are essential. An oversized unit can cycle inefficiently, while an undersized one may struggle in cold weather. Poor commissioning can leave a well-specified system underperforming for years.
Heat pumps must also be coordinated with the heat emitters and hot water system. Underfloor heating and correctly sized radiators allow the heat pump to run at lower flow temperatures, which improves efficiency. Hot water cylinders need to be sized for household demand and positioned to suit the layout.

Solar PV and Renewable Energy

Solar PV panels generate electricity on site, reducing the energy a home draws from the grid. In a DEAP assessment, solar PV contributes to both the energy performance and the renewable energy contribution, and is often used alongside a heat pump to close any gap.

Requirements vary by project type:
• Individual houses: panels are usually mounted on each roof, with output matched to household demand.
• Housing schemes: repeated house types allow standardised layouts, but orientation varies across a site and must be checked plot by plot.
• Apartment developments: roof space is shared and limited, so it must be balanced against plant, access and other roof uses.
Key design considerations include roof space, orientation and pitch, shading, system sizing, metering, and how much of the generated electricity will be used on site.
Solar PV should be integrated into the overall energy strategy from the start. Treating it as a late add-on often leads to awkward roof layouts, cable routing problems and compromised performance.

Ventilation and Indoor Air Quality

As homes become more airtight, they lose the uncontrolled draughts that once provided accidental ventilation. A planned ventilation strategy is needed to remove moisture, cooking odours and pollutants and to supply fresh air.

Two common approaches are:
• Mechanical ventilation with heat recovery (MVHR): extracts stale air and supplies fresh air continuously, recovering heat from outgoing air to warm the incoming supply.
• Demand-controlled ventilation (DCV): adjusts ventilation rates automatically based on humidity or occupancy, reducing energy use when demand is low.
Ventilation, air quality, moisture management and energy efficiency are closely linked. Too little ventilation risks condensation and mould. Too much, or poorly controlled ventilation, wastes heat. Correct system selection, duct design and commissioning are essential, including measuring airflows to confirm the system performs as designed.

Insulation, Airtightness and Heating Controls

Good building fabric is the foundation of every energy strategy. High levels of insulation in walls, roofs and floors, high-performance windows and doors, and careful detailing at junctions all reduce heat loss.

A well-insulated, airtight home needs less heat. That allows smaller heating systems, lower running costs and better comfort, and it makes the renewable energy requirement easier to meet.

Heating controls ensure that energy is used only when and where it is needed. Smart thermostats, zoned controls, time and temperature scheduling and energy management systems help occupants run their homes efficiently.

These measures must be designed as an integrated system. The fabric sets the heating demand, which sizes the heat pump, which shapes the solar PV and ventilation strategy. A change to one affects the others.
From heat pumps and solar PV to ventilation and heating controls, NetZero provides integrated energy solutions for new-build housing and apartment developments across Ireland.

Planning and Delivering Energy Solutions Across Housing and Apartment Developments

Understanding the technology is only half the challenge. The other half is delivering it on time, on budget and to the required standard across dozens or hundreds of units. That depends on early coordination between developers, architects, engineers, M&E consultants, BER assessors and installation contractors.

The stages of an integrated energy solution

1. Early-stage energy strategy and feasibility. Agree performance targets, review site constraints and test which combination of systems suits the scheme and budget.
2. System design and specification. Size heat pumps, ventilation and solar PV for each unit type, and coordinate plant locations, service routes and roof layouts with the design team.
3. NZEB compliance and energy performance assessments. Run DEAP calculations on the proposed specification to confirm compliance before it is locked in.
4. Procurement and construction scheduling. Secure equipment in good time and align deliveries and installation windows with the main contractor’s programme.
5. Installation and coordination between trades. Sequence first fix, second fix and external works so energy systems do not clash with other trades or compromise airtightness.
6. Testing, commissioning and certification. Complete airtightness testing, commission heat pumps and ventilation, measure airflows, and produce final BER certificates.
7. Handover and ongoing servicing. Provide clear documentation and user guidance, and put servicing arrangements in place so systems keep performing.

Housing estates versus apartment developments

On housing estates, the challenge is consistency at scale. The same specification is repeated across many plots, so a design flaw is repeated too. Efficient phasing and standardised installation methods help keep programmes on track.

Apartment developments bring different practical challenges:
• Plant space: heat pumps, cylinders and ventilation units need space within apartments or in shared plant rooms.
• Access: external units and roof plant need safe access for installation and future maintenance.
• Pipework distribution: services must run through multiple floors and risers without compromising fire stopping or airtightness.
• Acoustics: heat pumps and ventilation units must be located and specified to avoid noise issues for residents.
• Roof space: solar PV competes with plant, access routes and other roof uses.
• Metering arrangements: shared systems require fair, transparent metering for each unit.

Common project risks

The most common risks are late specification changes, poor coordination between suppliers and incomplete commissioning. A late change to the heating system can force a rerun of DEAP calculations and a redesign of services. Multiple subcontractors working in isolation can create clashes and gaps. Rushed commissioning can leave systems underperforming and generate callbacks after handover.

Each of these leads to installation delays and rework, which cost money and can push out completion dates.

The value of an integrated provider

Working with an integrated energy solutions provider simplifies coordination. With one partner responsible for heat pumps, solar PV, ventilation and controls, there are fewer interfaces between specialist contractors, clearer responsibility, and a single point of contact for the main contractor and design team.

Project scenario: a 60-unit mixed housing scheme

Consider a scheme of 40 semi-detached houses and 20 apartments. At feasibility stage, the energy partner recommends individual air-to-water heat pumps for the houses and compact in-apartment heat pumps for the apartments, with solar PV on every roof and MVHR throughout.
DEAP calculations run at design stage confirm each unit type complies. Plant locations, ductwork routes and roof layouts are agreed with the architect before construction drawings are issued. Installation is phased to follow the main contractor’s programme, block by block. Each unit is airtightness tested, commissioned and certified before handover, with servicing arranged for the management company.
The result is one coordinated delivery, fewer clashes on site and no late surprises at compliance stage.

Choosing the Right Energy Solutions Partner for Your Development

On a large residential development, the energy systems partner affects far more than the plant installed. They influence compliance, programme, budget and how well the homes perform for years after handover. Choosing the right partner is one of the most important decisions a development team makes.

What to look for:
• Multi-unit residential experience: a track record of delivering housing estates and apartment schemes, not just one-off installations.
• Expertise across systems: in-house knowledge of heating, ventilation, renewable energy and wider building services.
• Regulatory understanding: a clear grasp of Part L, NZEB, DEAP and the move towards zero-emission buildings.
• Procurement and supply chain capacity: the ability to secure equipment in the volumes and timescales a large scheme requires.
• Coordination with main contractors and consultants: working within the main contractor’s programme and responding to the design team.
• Quality assurance and health and safety: documented processes for installation quality and safe working on site.
• Testing, commissioning and handover: a structured approach to proving systems work as designed, with clear handover documentation.
• Long-term service and maintenance: the capacity to support systems for many years after occupation.

When heat pumps, solar PV, ventilation and controls are delivered by separate contractors, responsibility for how they work together can fall between the gaps. A joined-up partner designs, installs and commissions the systems as one, so performance issues are easier to prevent and quicker to resolve.

Plan for the long term

Servicing and maintenance should influence system selection from the outset. This matters most in apartment developments and managed residential schemes, where an AHB, local authority or management company will be responsible for the systems over decades. Factors such as access to plant, availability of parts, servicing intervals and metering all affect long-term running costs and resident satisfaction.

How NetZero supports developers

NetZero works across the full building lifecycle, from early energy strategy and design through installation, commissioning, servicing and maintenance. By bringing heat pumps, solar PV, ventilation and related building services together under one partner, we help development teams reduce interfaces, protect programmes and deliver homes that meet today’s standards and are ready for the next.

We understand the commercial realities of residential construction: tight delivery programmes, fixed budgets, compliance sign-off and the need for homes that perform well long after completion.

Ready to Start a Building Project That Requires NZEB Compliance?

Meeting NZEB and wider energy performance requirements takes a coordinated approach from the earliest project stages. Heat pumps, solar PV, ventilation, insulation and heating controls must be designed to work together, not added one by one. Early planning helps developers manage compliance, control costs and protect delivery programmes.
An experienced energy solutions partner makes that coordination simpler. NetZero supports developers through design, installation, commissioning and ongoing maintenance.

Want to learn more about NZEB planning and compliance requirements in Ireland? Contact NetZero Group today and find out how we can help design your new residential buildings.