Best Hot Water System for New Builds

Choosing the best hot water system for a new build is easier when you make the decision before plumbing, electrical, gas and slab locations are finalised. A new home gives you more flexibility than a replacement job, but it also means the hot water system needs to match the house design, energy source, number of bathrooms, outdoor layout and long-term running costs. At Hot Water Outlet, you can compare supply-only hot water systems online, including electric hot water systems, heat pump hot water systems, gas hot water systems, instant gas hot water systems, instant electric hot water systems and compatible valves, pipework and fittings.

Quick Answer

For most new builds, the best hot water system depends on the home’s energy plan.

If the new build is all-electric or has solar power, a heat pump hot water system is often worth comparing, provided the home has suitable outdoor airflow, drainage, noise placement and electrical setup.

If the home does not have gas but needs a simple, familiar option, a correctly sized electric hot water system may suit.

If the new build has natural gas or LPG, a suitable instant gas hot water system may suit homes that need strong recovery and compact outdoor placement.

The best time to choose the system is before the builder, plumber, electrician and gas fitter finalise the service locations.

Best Hot Water System Options for New Builds

Why New Builds Need Early Hot Water Planning

A new build gives you the chance to design the hot water setup properly from the start. That can make the system easier to install, easier to service and better matched to the home.

Hot water planning can affect:

• Plumbing rough-in

• Electrical circuit location

• Gas pipe sizing

• Outdoor slab or platform location

• Drainage

• Relief valve discharge

• Heat pump condensate drainage

• Solar power usage

• Noise placement

• Pipe run length

• Bathroom layout

• Kitchen and laundry locations

• Future servicing access

Leaving the hot water decision too late can limit your options. For example, choosing a heat pump after the outdoor area is finished may create problems if there is no suitable airflow, drainage or slab location.

Key Buyer Checks Before Choosing a New Build Hot Water System

Before buying a supply-only hot water system online for a new build, check:

• Number of people expected to live in the home

• Number of bathrooms

• Number of showers

• Whether bathrooms may be used at the same time

• Whether the home has a bath or spa

• Whether the home will have solar power

• Whether the home will be all-electric

• Whether natural gas or LPG is available

• Electrical supply and switchboard design

• Gas pipe sizing if gas is planned

• Outdoor space for the hot water system

• Heat pump airflow

• Drainage location

• Noise placement

• Pipe run distance to bathrooms and kitchen

• Builder requirements

• Plumbing and electrical rough-in timing

• Required valves and fittings

Supply-only pricing usually does not include installation, plumbing labour, electrical work, gas fitting, old unit removal, disposal, valves, fittings, pipework changes, drainage work, switchboard upgrades, gas upgrades, regulator changes, LPG bottle work, controller wiring, compliance upgrades, concrete bases, platforms or delivery beyond what is shown at checkout.

Plumbing, gas fitting and electrical work must be completed by appropriately licensed tradespeople.

Heat Pump Hot Water Systems for New Builds

Heat pump hot water systems are one of the most popular options to compare for new builds, especially where the home is designed around electricity and solar power.

A heat pump uses electricity to move heat from the surrounding air into the water. It can be a good fit for new homes where the system location is planned early and the builder can allow for airflow, drainage and access.

Brands commonly compared include iStore hot water systems, Stiebel Eltron hot water systems, Envirosun hot water systems and Emerald Energy.

Heat Pumps May Suit New Builds When

• The home is all-electric

• Solar power is planned

• There is suitable outdoor airflow

• Condensate drainage can be included in the design

• Noise placement can be planned away from bedrooms and neighbours

• The electrical circuit can be allowed for early

• The system has enough capacity for the household

• Long-term running cost is a priority

Heat Pumps May Not Suit When

• There is no suitable outdoor location

• The system would be too close to bedrooms

• The system would be too close to neighbours

• Airflow is restricted

• Condensate drainage cannot be managed

• The system location blocks access

• The builder has not allowed space for the unit

Heat pump rebates, STCs and incentives can change and depend on the product, installer, property, purchase type and program rules. Do not assume a rebate applies without checking current eligibility.

Electric Storage Hot Water Systems for New Builds

Electric hot water systems can suit new builds where a simple, familiar hot water system is preferred.

Electric storage systems are available in a wide range of tank sizes and are often straightforward to plan into a new home. They may suit smaller homes, investment properties, townhouses, basic builds or homes where a lower upfront product cost is a priority.

Brands commonly compared include Rheem hot water systems, Dux hot water systems, Vulcan hot water systems and Stiebel Eltron hot water systems.

Electric Storage May Suit New Builds When

• The home is all-electric

• A simple system is preferred

• The home has low to moderate hot water demand

• There is enough space for a storage tank

• The electrical supply is planned correctly

• Noise needs to be minimal

• The system location has suitable drainage

Electric Storage Buyer Checks

Check:

• Tank capacity

• Element size

• Recovery rate

• Indoor or outdoor rating

• Electrical circuit requirements

• Off-peak tariff options if relevant

• Safe tray requirements if installed indoors

• Drainage and relief valve discharge

• Tempering valve requirements

• Space for future replacement

Electric storage may be simple, but it still needs to be sized properly. A new build with multiple bathrooms, a bath and a large family may need more capacity than a small townhouse or unit.

Instant Gas Hot Water Systems for New Builds

Instant gas hot water systems, also known as continuous flow gas systems, can suit new builds where natural gas or LPG is available and planned from the start.

Instant gas systems heat water as it is used rather than storing a full tank. They can be useful for homes with limited space or homes where strong recovery is important.

Common brands include Rinnai hot water systems, Bosch hot water systems and Rheem hot water systems.

Instant Gas May Suit New Builds When

• Natural gas or LPG is available

• Gas is already planned for cooking or heating

• Storage tank space is limited

• The home has multiple bathrooms

• Fast recovery is important

• The system can be located externally or correctly flued

• Gas pipe sizing can be designed from the start

Natural gas and LPG are not interchangeable. A natural gas unit must not be connected to LPG unless it is specifically converted and approved by a licensed gas fitter, and an LPG unit must not be connected to natural gas unless the same applies.

External gas hot water units are outdoor/external only unless the product is specifically designed and approved for internal or flued installation.

Instant Gas Buyer Checks

Check:

• Natural gas or LPG

• Required flow rate

• Number of bathrooms

• Whether showers may run at the same time

• Gas pipe sizing

• Gas meter capacity

• LPG bottle and regulator setup if applicable

• Minimum flow rate

• Water pressure

• Controller requirements

• External clearances

• Flue requirements if internal

• Distance to bathrooms and kitchen

For a new build, the gas pipe size should be planned before construction. Undersized gas pipework can limit performance or require changes later.

Gas Storage Hot Water Systems for New Builds

Gas hot water systems may suit some new builds, especially where the home is already designed around gas and a storage-style system is preferred.

Gas storage systems provide stored hot water with gas recovery. They may suit homes where gas is available and where the location, ventilation, flue and drainage are suitable.

Brands often compared include Rheem hot water systems, Dux hot water systems and Vulcan hot water systems.

Gas Storage Buyer Checks

Check:

• Natural gas or LPG

• Tank capacity

• Recovery rate

• Indoor or outdoor rating

• Flue and ventilation requirements

• Gas pipe sizing

• Safe discharge point

• Drainage

• Access for servicing

• Tempering valve requirements

Gas storage may suit some builds, but many new homes now compare heat pump, electric storage or instant gas depending on the energy plan.

Instant Electric Hot Water Systems for New Builds

Instant electric hot water systems may suit selected new build applications, but they are not always suitable for whole-home hot water.

Instant electric units can require significant electrical capacity, especially for showers and high-flow fixtures.

Instant Electric May Suit

• Small studios

• Powder rooms

• Kitchenettes

• Hand basins

• Detached offices

• Granny flat point-of-use applications

• Small low-demand areas far from the main hot water system

Instant Electric May Not Suit

• Whole-home high-flow use

• Multiple bathrooms

• Back-to-back showers

• Homes with limited electrical capacity

• High hot water demand

• Large families

Before buying instant electric, confirm the required electrical supply with a licensed electrician.

Best Hot Water System for All-Electric New Builds

For all-electric new builds, the most common options to compare are:

• Heat pump hot water systems

• Electric hot water systems

• Instant electric hot water systems for selected small applications

A heat pump may be worth comparing if the site has suitable airflow, drainage and noise placement. Electric storage may suit where simplicity and lower upfront product cost matter more.

For new builds with solar power, the hot water system should be planned with the electrical setup, solar design and household usage pattern in mind.

Best Hot Water System for New Builds With Solar

For new builds with solar power, a heat pump is often worth comparing because it can use electricity and may be timed to operate during solar production where the setup allows.

A standard electric storage system may also be considered, depending on tariff setup, timer controls, tank size and household demand.

When planning hot water for a solar home, check:

• System size

• Daily hot water use

• Solar system size

• Timer or control options

• Electrical circuit requirements

• Off-peak tariff arrangements

• Whether the system can operate during solar production

• Backup heating requirements

• Household usage pattern

Solar does not automatically make every hot water system suitable. The system still needs to match the home and be installed by licensed tradespeople.

Best Hot Water System for New Builds With Gas

For new builds with natural gas or LPG, the main options are usually:

• Instant gas hot water systems

• Gas hot water systems

Instant gas may suit homes that want compact placement and strong recovery. Gas storage may suit homes where a tank-style gas setup is preferred.

Gas should be planned early because pipe sizing, meter capacity, LPG regulator setup, appliance locations and clearances all matter.

Best Hot Water System for Large New Homes

Large new homes need careful sizing because there may be several bathrooms, large baths, multiple living areas and high simultaneous demand.

Common options to compare include:

• Larger heat pump systems

• Larger electric storage systems

• High-flow instant gas systems

• Multiple hot water systems

• Zoned systems

• Site-designed systems for large layouts

For large homes, pipe run distance matters. A system located far from bathrooms can increase wait time for hot water and waste water. Some homes may benefit from multiple systems or carefully planned pipe layouts.

Best Hot Water System for New Builds With Granny Flats

New builds with granny flats or secondary dwellings may need separate hot water systems.

Separate systems may suit when:

• The granny flat is rented separately

• Billing should be independent

• The main home and granny flat are far apart

• One household should not affect the other

• Access for servicing should be separate

• The granny flat has its own kitchen, bathroom and laundry

A granny flat may use a smaller electric hot water system, a compact instant gas hot water system where gas is suitable, or a heat pump only where location and airflow suit.

Best Hot Water System for Investment New Builds

For investment properties, the best hot water system is usually one that is practical, reliable, easy to service and matched to tenant demand.

Common choices include:

• Electric storage for simple all-electric rentals

• Heat pump where energy efficiency and site conditions suit

• Instant gas where gas is already planned

• Separate systems for dual occupancy or granny flat rentals

For investment properties, consider:

• Tenant usage

• Replacement cost

• Ease of servicing

• Access

• Warranty conditions

• Compliance requirements

• Risk of hot water complaints

• Whether the system is easy for tenants to understand

What Size Hot Water System Does a New Build Need?

Sizing depends on the number of people, bathrooms, fixtures and hot water habits.

Do not choose a system based only on bedrooms. Bathrooms, showers, baths, guest use and simultaneous demand matter.

Hot Water System Location for New Builds

System location is easier to plan during construction than after handover.

Good location planning can help with:

• Shorter pipe runs

• Faster hot water delivery

• Easier servicing

• Better drainage

• Lower noise impact

• Better heat pump airflow

• Easier future replacement

• Better clearance for gas appliances

Location Checks

Check:

• Distance to bathrooms

• Distance to kitchen

• Outdoor access

• Side access

• Slab or platform position

• Drainage point

• Relief valve discharge

• Heat pump condensate

• Bedroom windows

• Neighbouring properties

• Gas appliance clearances

• Future replacement access

A system that is easy to install but hard to service may create problems later.

Valves and Fittings for New Build Hot Water Systems

New build hot water systems often require more than just the unit.

Depending on the system and property design, you may need compatible valves, pipework and fittings, such as:

• Tempering valve

• Pressure limiting valve

• Duo valve

• Expansion control valve

• Isolation valve

• Non-return valve

• Relief drain materials

• Connection fittings

• Pipework materials

• Safe tray or drainage parts

The correct parts depend on the system, water pressure, installation location, local requirements and whether the setup is electric, heat pump, gas or instant gas.

Common Mistakes When Choosing Hot Water for a New Build

Leaving the Decision Too Late

Hot water should be planned before service locations are finalised. Late changes can affect plumbing, electrical, gas, drainage and outdoor layout.

Choosing the Cheapest System Only

The cheapest product may not be the best long-term choice if it is undersized, inefficient or poorly suited to the home.

Forgetting About Pipe Run Length

Long pipe runs can increase wait time for hot water. In large homes, system location matters.

Choosing a Heat Pump Without Checking Airflow

Heat pumps need airflow and drainage. They are not suitable for tight enclosed spaces.

Putting a Heat Pump Too Close to Bedrooms

Noise placement should be considered before the system location is finalised.

Buying the Wrong Gas Type

Natural gas and LPG are different. Always select the correct gas type.

Not Planning Gas Pipe Size

Gas pipe sizing should be planned during construction. It can affect instant gas performance.

Using an External Gas Unit Indoors

External gas hot water units are outdoor units unless specifically designed and approved for internal or flued installation.

Ignoring Valves and Compliance Parts

Supply-only pricing does not include all parts and labour needed for installation. Valves, fittings, drainage and compliance parts may be required.

Not Allowing Future Access

Make sure the system can be serviced and replaced later without major access problems.

Best Brands for New Build Hot Water Systems

The best brand depends on the system type, home design and buyer priorities.

Rheem

Rheem hot water systems are commonly compared across electric storage, gas storage, instant gas and heat pump categories. Rheem may suit buyers wanting a broad range of common new build options.

Rinnai

Rinnai hot water systems are commonly compared for instant gas and continuous flow hot water systems, especially where gas is planned for the home.

Dux

Dux hot water systems are often compared for practical electric and gas storage systems.

Bosch

Bosch hot water systems are commonly compared for instant gas applications.

Vulcan

Vulcan hot water systems are often considered for budget-conscious electric and gas storage options.

iStore

iStore hot water systems are commonly compared in the heat pump category, especially for new homes moving toward efficient electric hot water.

Stiebel Eltron

Stiebel Eltron hot water systems may suit buyers comparing heat pump, electric and instant electric options.

Envirosun and Emerald Energy

Envirosun hot water systems and Emerald Energy are commonly compared for heat pump hot water systems where site conditions suit.

Buyer Checklist Before Ordering Online

Before ordering a supply-only hot water system for a new build, confirm:

• Home size

• Number of occupants

• Number of bathrooms

• Number of showers

• Whether a bath or spa is included

• Whether the home is all-electric

• Whether solar power is planned

• Whether natural gas or LPG is planned

• Required tank size or flow rate

• Electrical circuit requirements

• Gas pipe sizing if applicable

• Outdoor system location

• Heat pump airflow

• Noise placement

• Drainage location

• Pipe run distances

• Slab or platform requirements

• Valve and fitting requirements

• Builder rough-in timing

• Licensed plumbing, electrical and gas fitting requirements

Supply-Only vs Installed Cost

Hot Water Outlet sells supply-only hot water systems and accessories online. Supply-only pricing is useful for comparing product costs, but it is not the same as total installed cost.

The final installed cost may depend on:

• Licensed plumbing labour

• Licensed electrical work

• Licensed gas fitting

• Valve installation

• Pipework

• Electrical circuits

• Gas pipework

• LPG bottle or regulator setup

• Switchboard work

• Drainage

• Slab or platform

• Compliance requirements

• Builder coordination

• Delivery access

Where appropriate, Hot Water Outlet may help organise quotes from reputable installers.

FAQ: Best Hot Water System for New Builds

What is the best hot water system for a new build?

The best hot water system for a new build depends on the home’s energy source, number of bathrooms, expected household size and system location. Heat pumps may suit all-electric and solar homes, electric storage may suit simple builds, and instant gas may suit homes with suitable gas supply.

Should I choose heat pump hot water for a new build?

A heat pump may be a good option if the home has suitable outdoor airflow, drainage, noise placement and electrical setup. It is often worth comparing for all-electric homes and homes with solar power.

Is electric hot water good for a new build?

Electric hot water can be a practical option for new builds, especially where gas is not planned. The correct tank size, element size, tariff setup and electrical supply should be checked.

Is instant gas hot water good for a new home?

Instant gas may suit a new home if natural gas or LPG is available and gas pipe sizing is planned correctly. The unit must match the correct gas type and be installed in an approved location.

When should I choose the hot water system for a new build?

The hot water system should be chosen before plumbing, electrical, gas, drainage and slab locations are finalised. Early planning gives more flexibility and can reduce problems later.

What size hot water system do I need for a new build?

Sizing depends on the number of people, bathrooms, showers, baths and simultaneous use. A family of four may compare 250L–315L storage, a suitable heat pump or a 20L–26L instant gas system, depending on the home setup.

Can I use solar power with a hot water system?

Yes, but the setup needs to be planned. Heat pumps and electric storage systems may be matched with solar strategies where suitable, but the system, timer, circuit and household usage pattern need to be checked.

Do new build hot water systems need tempering valves?

Many hot water installations require temperature control for safety and compliance. A licensed plumber should confirm the correct valve setup for the specific system and property.

Does supply-only pricing include installation?

No. Supply-only pricing generally does not include installation, plumbing labour, electrical work, gas fitting, valves, fittings, pipework, drainage, slab work or compliance upgrades.

Can Hot Water Outlet install the system?

Hot Water Outlet sells supply-only hot water systems and accessories online. Plumbing, gas fitting and electrical work must be completed by appropriately licensed tradespeople. Where appropriate, Hot Water Outlet may help organise quotes from reputable installers.

Final Thoughts

For new builds, the best hot water system is the one that matches the home’s energy plan, bathroom layout and long-term usage. Heat pumps may suit all-electric and solar homes, electric storage may suit simple builds, and instant gas may suit homes where gas is already planned.

The key is choosing early. Hot water affects plumbing, electrical, gas, drainage, system location and future servicing access.

Browse hot water systems, compare electric hot water systems, heat pump hot water systems, gas hot water systems, instant gas hot water systems, instant electric hot water systems and compatible valves, pipework and fittings online at Hot Water Outlet.