If the wrong heating is used — such as a heat pump in the hallway — it can be very ineffective, says Cowan. Likewise an electric heater in a large cavernous room isn't going to be efficient or effective.
The main options to discuss if you're adding new heating to the home are:
• Heat pumps. These are often popular with homeowners and tenants. They have one unit inside and one outside and are energy efficient. It's important not to simply buy the cheapest one because it might not be suitable for your space.
• Central heating. This involves moving warmth into rooms via air ducts or hot water pipes. Typically there is a boiler or heat pump in one location and the heat is pumped to where it's needed in the home.
• Electric heating. Electric heating can be costly to run, but is cheap to buy. Panel heaters that put out a low level of heat and have low surface temperatures are popular, but not necessary effective. Blower heaters heat rooms quickly. Convection, oil column and micathermic heaters may take a long time to heat up a cold room. Bar-style radiant heaters are good for large rooms, but can be a fire risk and are dangerous for children.
• Underfloor heating. Electric cables or water-filled pipes can be embedded into a concrete slab or installed under existing flooring providing it's well insulated. It uses a lot of energy to bring the floor up to temperature, but can be left on all the time in the cooler months so is good for someone who is home most of the time.
• Wood and pellet burners. These put out a lot of heat, but aren't suitable for everyone. For example some people aren't able to manage their wood supply.
Each home and owner is different and homeowners often make poor choices, sometimes on the back of advice from the vested interests of salespeople. A number of councils, including Auckland, provide free in-home advice about (how to heat up your home).
Eco Design Advisors do not sell products, and are funded to provide a free one-hour consultation. Or you can get advice from a certified Home Performance Adviser, see here.
• To book a free EDA consultation in Auckland call 0508 326 337 or email lowcarbonliving@aucklandcouncil.govt.nz Or check out Smarterhomes.org.nz for more information.