Questions to ask your plumber about heating and energy

When you're building a new home, it's easy to focus on the visible decisions: kitchens, flooring, bathrooms and paint colours. But some of the most important decisions are hidden behind the walls.

The heating system you choose, how the home is designed to perform, whether it's set up for future energy needs and even where fuel will be stored can all affect comfort, running costs and long-term efficiency for years to come. The challenge is that many of these decisions are made long before you get the keys. That's why it's important to ask the right questions early and to ask them to the right people.

If you're planning a self-build or working on a new home, your plumber or heating installer will usually be one of the key people to speak to about your heating system, fuel source, controls and installation requirements. Depending on the build, you may also need input from your builder, architect or BER assessor on areas such as insulation, ventilation and overall energy performance.

This guide covers the key questions to ask your plumber about heating and energy before plans are finalised.

Why heating and energy questions matter before you build

The cheapest time to change your heating plans is before construction starts. Once pipework, heating systems, ventilation and fuel storage locations have been agreed and installed, making changes becomes significantly more expensive.

Heating decisions also influence far more than your winter energy bills. They affect:

• Comfort throughout the home
• Energy efficiency
• Running costs
• BER rating
• Future upgrade options
• Long-term property value

Since December 2018, all new homes in Ireland must meet Nearly Zero Energy Building (NZEB) standards under Part L of the Building Regulations. That means energy performance is now a fundamental part of the build process rather than something that's considered afterwards.

The good news is that today's homeowners have more options than ever before. The key is understanding which solution suits your property, location and lifestyle and making sure the people involved in the build are aligned early.

If you're still comparing technologies, our guide to the our guide to the best home energy options for new builds and older homes in Ireland explores the main heating choices in more detail.

Questions about the heating system

What heating system are you recommending, and why?

Your plumber or heating installer should be able to explain not only what they're recommending, but why it's suitable for your home. Different heating systems work better in different situations.

For example:

• Heat pumps often perform best in highly insulated homes with excellent airtightness
• LPG boilers can provide an efficient alternative for homes that aren't connected to the natural gas grid
• Hybrid systems combine multiple technologies to balance efficiency and flexibility
• Solar panels can complement many heating systems by helping reduce electricity demand

There is no single solution that's right for every home. The best option depends on factors such as location, insulation levels, heating demand and budget.

Why it matters: Choosing a heating system that suits the property from day one can help avoid costly upgrades or performance issues later.

Is the home connected to the natural gas grid? And what if it isn't?

This is one of the most important questions for anyone building outside major urban areas. Many self-builders assume natural gas will be available, only to discover later that their site isn't connected to the network.

If your property is off-grid, you'll need an alternative fuel source for heating and hot water. For many rural homes, LPG provides a convenient solution that offers many of the same benefits as mains gas, including responsive heating, hot water and cooking.

Establishing this early helps ensure the heating system, fuel supply and installation requirements are incorporated into the build from the beginning.

Why it matters: Your fuel source influences everything from system design to storage requirements and future running costs.

Who will install and certify the gas and heating work?

Any gas installation should be completed by a suitably qualified installer. In the Republic of Ireland, gas work must be carried out by a Registered Gas Installer (RGI). In Northern Ireland, gas work should be completed by a Gas Safe registered installer.

Your plumber or heating installer should be able to confirm:

• Who is installing the system
• Their qualifications and certifications
•  What commissioning and safety checks will be completed
• What documentation you'll receive when the work is finished

Why it matters: Proper installation affects safety, efficiency and compliance with building regulations.

Where will fuel be stored, and how is it delivered?

If you're building an off-grid home and considering LPG, it's important to ask early how fuel will be stored and how it will be supplied once the home is occupied.

In both the Republic of Ireland and Northern Ireland, the most suitable LPG storage option will depend on factors such as the property's size, outdoor space and heating requirements. This may be a bulk LPG tank or LPG cylinders. 

Bulk tanks are often used where LPG will be supplying the home's main central heating, hot water and cooking over the long term. LPG cylinders can also be used for central heating, hot water and cooking, and may be a good fit for smaller properties or homes with lower energy demand. Your plumber or gas installer should be able to talk you through which setup makes most sense for the property and how that choice could affect the wider build.

It's also worth discussing practical details during the planning stage, including:

• where a tank or cylinders will be located
• access for deliveries
• safety clearances
• how the storage area will fit into the overall site layout
• future maintenance access

Why it matters: Fuel storage affects site design, delivery access and the day-to-day convenience of running your heating system.

Questions about energy efficiency and BER

When people hear the term BER (Building Energy Rating), they often think about heating systems. However, BER measures how efficiently the entire home performs.

A highly efficient heating system can only do so much if heat is constantly escaping through walls, windows or poor ventilation. That's why it's worth discussing the following questions early with the right people; usually your plumber alongside your builder, architect or BER assessor.

What BER are we targeting, and how will we achieve it?

The Building Energy Rating (BER) measures how energy-efficient a home is, from A (most efficient) to G (least efficient). New builds in Ireland are designed to meet strict energy performance requirements, but it's still worth understanding what BER your team is targeting and how they plan to achieve it.

A strong BER can help reduce energy consumption, lower running costs and make your home more comfortable year-round. It can also be a valuable selling point should you decide to move in the future.

Ask what measures are contributing to the home's energy performance, including:

• Insulation levels
• Airtightness measures
• High-performance windows and doors
• Ventilation systems
• Heating system design
• Renewable energy technologies, where applicable

The best BER results don't come from one feature alone. They're achieved when the heating system, building fabric and ventilation strategy all work together as part of a well-designed energy plan.

Why it matters: A better BER can reduce energy bills, improve comfort and support the long-term value of your home.

How will insulation, airtightness and ventilation be handled?

These three elements work hand-in-hand. Insulation helps retain heat. Airtightness reduces unwanted heat loss. And ventilation ensures fresh air continues to circulate throughout the home.

Many modern homes use Mechanical Ventilation with Heat Recovery (MVHR) systems. These systems continuously extract stale air from rooms such as kitchens and bathrooms while bringing fresh air into the home. As the air passes through the system, heat from the outgoing air is recovered and used to warm the incoming air, helping maintain comfort while reducing energy loss. For the system to work as intended, it should be properly commissioned and balanced after installation to ensure the correct airflow throughout the home. Your plumber may not be responsible for every element of this, but they should be able to explain how the heating system will work alongside the home's ventilation and overall energy strategy. It's also worth asking your wider build team how insulation, airtightness and ventilation will be tested before handover.

Why it matters: Even the most efficient heating system will struggle to perform if heat is escaping through the building or ventilation isn't properly managed.

Questions about future-proofing and running costs

Building a home is a long-term investment, so it's worth thinking beyond what works today.

The energy landscape is changing. New technologies are emerging, renewable fuels are becoming more widely available, and homeowners are looking for ways to reduce emissions without sacrificing comfort or convenience. That doesn't mean you need to future-proof for every possible scenario. But it does mean asking a few sensible questions now could give you more flexibility later.

Is the system BioLPG-ready?

If you're building an off-grid home and considering LPG, it's worth asking whether the system can use BioLPG in the future.

BioLPG is a renewable gas made from sustainably sourced feedstocks. It's chemically identical to conventional LPG, which means it can be used in the same boilers, appliances, tanks and infrastructure without modification.

That's one of its biggest advantages. As lower-carbon energy options become increasingly important, homeowners can transition from LPG to BioLPG without needing to replace their heating system or undertake costly upgrades.

For new-build homeowners, this provides greater flexibility. You can install an efficient LPG heating system today while keeping the option to reduce emissions in the future using the same setup.

Why it matters: BioLPG offers a straightforward route towards lower-carbon heating without the disruption or expense of replacing boilers, appliances or fuel infrastructure later on.

Can the system work alongside solar panels or other technologies?

Many homeowners don't stop improving their home once the build is complete. Solar panels, battery storage, smart heating controls and other energy-saving technologies are often added over time.

That's why it's worth asking how your heating system could fit into those future plans. Some homes benefit from hybrid setups that combine different technologies to improve efficiency and give homeowners more flexibility over how they use energy. For example, a heating system might work alongside solar PV panels or smart controls that help manage energy use more effectively throughout the day.

Even if you're not planning to add these features straight away, designing with them in mind can make future upgrades much simpler.

Why it matters: A heating system that can adapt to future technologies gives you more flexibility as your home and energy needs evolve

Are smart heating controls included?

Smart heating controls do so much more than simply switch the heating on and off.

Depending on the system, they can allow you to:

• Adjust heating remotely using an app
• Create room-by-room schedules
• Monitor energy usage
• Set different temperatures for different areas of the home
• Optimise heating performance based on your daily routine

This level of control can be particularly useful in larger homes where different rooms are used at different times of the day. Rather than heating the entire house to the same temperature, smart controls can help ensure energy is only used where and when it's needed.

While the heating system itself is important, how you control it can have a significant impact on both comfort and efficiency.

Why it matters: Better control can help reduce unnecessary energy use, improve comfort throughout the home and give you greater visibility over how your heating system performs day to day.

Printable checklist of questions for your plumber

When you're planning a new build, it's easy to focus on layouts, finishes and timelines. But the decisions made about heating and energy can have a lasting impact on comfort, running costs and future flexibility.

Before you sign off on your plans, use the checklist below as a conversation starter with your plumber, builder, architect or BER assessor, depending on who's responsible for each part of the project.

Expert tip: Don't wait until the build is underway to discuss heating and energy. Decisions about fuel type, boiler location, ventilation systems and energy infrastructure are much easier (and often far less expensive!) to make during the design stage than after construction begins. The earlier these conversations happen, the more options you'll have and the easier it will be to create a home that's comfortable, efficient and ready for the future.