Frequently asked questions
Heat pumps
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A heat pump is a type of air conditioner that can reverse how it operates—so instead of just cooling your home in summer like a standard air conditioner, it can also heat your home in winter. Not all air conditioners have this reverse-cycle feature, which is why heat pumps are so popular in New Zealand for year‑round heating and cooling.
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The time for a heat pump installation can vary depending on the type of system and your home’s layout, but most standard single‑room installations are typically completed within 4-5 hours. More complex systems, such as multi‑room or ducted heat pump setups, can take 1–2 days. Our team will ensure that the heat pump is sized and positioned correctly for efficient heating and cooling, to get the most out of your heat pump.
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Choosing the right heat pump depends on your home’s size, layout, your desired features and whether you would like single‑room or whole‑home comfort. A reputable assessor will check your space and recommend systems that suit your needs, including trusted, high‑efficiency brands like Mitsubishi, Daikin, Hitachi and Fujitsu, to ensure optimal performance and energy savings. Good insulation is also crucial, as homes that retain heat are cheaper to heat and feel cooler in the summer.
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Heat pumps are one of the most efficient ways to heat (and cool) a home. They can deliver more heat energy than the electricity they consume—often 3‑5 times more—making them cheaper to run long‑term than many other heating options, including electric space heaters or some gas systems. They can also heat a room very quickly and improve year‑round comfort by providing cooling in warm months.
Insulation
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Ceiling and underfloor insulation helps to keep your home warm, dry and energy‑efficient by reducing heat loss through ceilings and underfloors. A well‑insulated house is easier and cheaper to heat, more comfortable year‑round, and healthier for occupants because it helps reduce dampness and condensation—particularly when paired with a ground vapour barrier.
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We can supply and install ceiling and underfloor insulation, as well as ground vapour barriers, to reduce moisture underneath your home. Every home is different, so an expert assessment will determine the materials and R‑values best suited to your property’s layout and thermal needs. We offer both fibreglass and polyester insulation from trusted local brands like Pink Batts and Mammoth.
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Insulation can degrade over time, especially if it’s more than ten years old or has been disturbed by renovations. Old or poorly installed insulation won’t perform effectively and may need either a top-up or a full replacement. A professional assessment can help you decide what’s needed by our team.
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Professionally installed insulation ensures that it is fitted correctly, meets current New Zealand standards, and performs as intended. Professional installers have the training and experience to assess your home, recommend the right insulation and R‑value, and complete the job to high standards. Proper installation also helps avoid gaps, compression or moisture issues that can reduce effectiveness.
Central heating
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A central heating system warms your entire home from one central control panel and outdoor unit rather than individual room heaters. In modern installations this is often achieved using a ducted heat pump, which uses air ducts distributed throughout your roof or underfloor to quietly deliver warm air to multiple rooms. The system heats (or cools) air from a central outdoor heat pump unit and allows for smart features, such as setting timers or turning on specific rooms (so you don’t waste energy).
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Central heating systems can be based on different technologies, including ducted heat pumps, hydronic (warm‑water) radiators or pipe‑based underfloor heating. In New Zealand, ducted heat pump systems are increasingly popular because they provide energy-efficient, electric whole‑home heating and cooling without visible wall units. Here at Sustainability Trust, ducted heat pump systems are the only type of central heating/cooling that we offer, because of their sustainability and efficiency.
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Installing a central heating system—particularly a ducted heat pump—is a specialist job and should be carried out by trained, accredited installers who can design the ducting and pipework for your home. The time required varies with system type and house size, but experienced installers plan the layout, connect ducts or pipes and set up controls so your system runs efficiently and safely.
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Central heating delivers even warmth throughout your home, improving comfort and making it easier to maintain healthy indoor temperatures. It’s a long‑term investment that can add value to your property and improve living conditions for those sharing your house. No more cold bedrooms!
Hot water heat pumps
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In a nutshell, a hot water heat pump is an energy-efficient hot water system that heats your water by drawing heat from the air and transferring it into a hot water cylinder. Instead of generating heat directly like a traditional electric or gas system, it ‘moves’ existing heat using a refrigeration cycle, which makes it far more efficient—up to 6x more than traditional cylinders—while still delivering the same amount of hot water for your home.
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Yes, hot water heat pumps are significantly cheaper to run than standard electric or gas hot water systems. They typically use around 60–75% less electricity, which can lead to noticeable savings on your power bill over time. While the upfront cost is higher, the lower running costs mean they are often the most cost-effective option in the long run.
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The biggest benefits are energy efficiency, lower running costs and reduced emissions (particularly compared to gas systems). Because they use less electricity, if you’re plugged into the national grid, they’re better for the environment and can help lower your household’s carbon footprint. As the tank sizes we offer are up to 340 litres, they're also a great option for homes with higher hot water usage, and they can work even more sustainably when paired with solar power.
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The cost of installing a hot water heat pump can vary depending on the system you choose and your home’s setup, but in New Zealand you can typically expect to pay more upfront than a standard hot water cylinder: anywhere from $7–12,000. While the initial investment is higher, many homeowners find the long-term savings on energy bills help offset the cost over time. In some cases, green loans or other finance options may be available to help reduce the upfront expense, making it a more accessible upgrade.
Ventilation
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Good ventilation helps remove excess moisture, stale air and pollutants from your home. Without it, everyday activities like cooking and showering can lead to condensation, dampness and mould, which can impact both your home and your health. Our ventilation team focuses on helping Wellington homes stay dry and healthy through better airflow solutions.
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There are a range of ventilation solutions depending on your home, from simple improvements like opening windows more effectively, to extractor fans and full roof ventilation systems. Sustainability Trust can assess your ventilation needs at no cost and recommend the right option to reduce moisture and improve air quality.
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Yes! A well-ventilated home is typically drier, which makes it easier and more efficient to heat. By reducing dampness, ventilation helps your heating systems work more effectively, improving comfort and potentially lowering energy use.
Healthy Homes Standards
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The Healthy Homes Standards are a set of minimum requirements that landlords must provide for rental properties in New Zealand. They cover heating, insulation, ventilation, moisture control, drainage and draught stopping. They’re designed to ensure rental properties are warm, dry, and safe for tenants.
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Sustainability Trust provides expert advice and home assessments to check whether your rental meets the standards. Our team can identify any gaps, recommend improvements and help organise upgrades like insulation, heating, or ventilation to get your property compliant.
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Meeting the standards not only ensures legal compliance but also creates a healthier living environment for tenants. Warm, dry homes can reduce mould and improve overall wellbeing, while also protecting your property from long-term damage.
LED lighting
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LED lighting is far more energy-efficient than traditional bulbs, helping you reduce your power usage while still keeping your home well lit. It’s a simple upgrade that can make a noticeable difference to your energy bills and overall home efficiency.
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Yes, LED lights have a much longer lifespan than older lighting types, meaning fewer replacements and less maintenance over time. This makes them a cost-effective option for homeowners looking for a long-term lighting solution.
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Surprisingly, yes. Modern LED downlights can be safely covered with insulation, unlike older lights that require gaps in insulation to prevent fire risk (due to how hot they can get). LED lighting can therefore also help prevent heat loss and improve your home’s overall warmth and efficiency.
EV chargers
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While you can charge an electric vehicle using a standard power socket, a dedicated home EV charger is faster, ‘smarter’ and more efficient. You can programme your car to only charge during cheaper time-of-use hours of your power plan, for example. They’re also often faster, which is great if you forget to charge up and you need to be out the door! Sustainability Trust can help assess your home and recommend the best setup for your needs.
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The process usually starts with a home assessment to check your electrical capacity and home setup. From there, Sustainability Trust can supply and install a charger that suits your power plan, vehicle and usage, ensuring everything is safe and compliant.
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For most EV owners, yes. Having a charger at home makes daily charging simple and convenient, so your vehicle is always ready to go. You can programme the charging to coincide with your time-of-use electricity plan too. It also helps you get the most out of your EV’s efficiency without relying on public charging stations.
Te Aro Zero Waste
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You can drop off a wide range of hard-to-recycle items, including:
E-waste
Batteries
Plastic lids
Food and beverage cartons,
Unwanted electronics
Tools
Metal objects
We also accept items for reuse like curtains, jewellery, wool and packaging, helping give these materials a second life instead of sending them to landfill.
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Yes! Te Aro Zero Waste has a retail space where you can purchase quality secondhand and reconditioned items such as laptops, electronics, appliances, and household goods. It’s a great way to save money while supporting reuse and reducing waste in the community.
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We do! Te Aro Zero Waste offers repair education which gives you access to shared resources like sewing machines and tool kits through programmes like RepairED. This allows you to fix items instead of replacing them, while also learning practical skills and reducing waste.
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Te Aro Zero Waste has set opening hours throughout the week, making it easy to drop off items, shop, or access services at a time that suits you. Hours can vary, so it’s best to check the Sustainability Trust website before visiting, you can find our opening hours here.
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We can take some whiteware! We take washing machines and dryers, working and not working. We do not accept fridges and freezers.
Wellington Curtain Bank
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If you, or someone you live with has a Community Services Card or a SuperGold ComboCard, and you live in Wellington City, Porirua, or Kāpiti Coast, you may be eligible to get free curtains.
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Fill in the form on the Curtain Bank page and we will contact you about an in-home visit. We can provide curtains for people living with low-income in most areas of the Wellington Region.
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Yes, we can provide curtains for people who are renting, people who are living in temporary or emergency accommodation, and people who own their own home. We can’t usually provide curtains for people in social housing, e.g. Kāinga Ora and Te Toi Mahana, but we can talk to your landlord for you if you need curtains.
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We have multiple locations where you can donate good-quality curtains, fabric, and tracks, including Te Aro Zero Waste. Unfortunately, mouldy or sun-damaged curtains cannot be reused and must be taken to landfill.
You can also donate money or time here.
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Curtains are a relatively affordable form of insulation and can significantly reduce heat loss through windows.
Fully-lined, full length curtains can reduce heat loss by up to 45%. This can have a significant impact on making your home healthier, warmer, and drier.
In-home support
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If you, or someone you live with, is living with low-income, energy hardship, or have a child in the house with health issues, you may be eligible for support.
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Depending on your circumstances, we can offer in-home assessments, energy-saving advice, advocacy, and free products like draught-stopping, curtains and LED light bulbs. We can also help you access subsidised insulation and heating.
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Our healthy homes team supports anyone living with low-income, in all types of housing. This includes homeowners, renters and people in social housing and temporary accommodation.
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Once you get in contact with us, we'll call you to discuss how we can support you. If you're eligible, we'll arrange a visit where we can check how warm, dry and healthy your home is. Our assessors will then discuss with you how your whare can be improved and how we can help.
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Yes! Our in-home visits are always free. We will provide advice and support at no cost to you.
If there is anything we recommend that may cost money, such as insulation, we will discuss your options with you.
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There’s usually nothing you need to do at all! We will let you know if we need anything from you.
Our visits are not inspections. You don’t need to do anything special to prepare, and our assessors are friendly and supportive of all situations. We only ask that if there is a dog at the property, it is put in a separate area for the visit.