How to build an energy-efficient home using solar

There’s only so much you can do to make an existing home more energy efficient. To truly go carbon neutral and use less energy, sometimes you have to build an energy efficient home from scratch.

Solar power is an important part of any energy efficient home. By generating your own power, you’re cutting down on utility bills, reducing your carbon footprint, and ensuring you stay independent from electricity companies.

Here’s our step-by-step guide to building a truly sustainable home with solar.

Choose the right site

The road to energy efficiency starts with careful design. There are a number of energy efficient materials and construction practices that should be integrated into any design of an energy efficient home - solar-powered or otherwise. Consult with architects and builders who specialise in efficiency to ensure you incorporate these principles.

• Site selection. An energy efficient home has to be built in the right place. Unobstructed sun, flat land, and low weather exposure is ideal. Solar access is especially important to ensure you’ll have enough sunlight on wall and roof surfaces. Few sites will be absolutely perfect, but the more boxes ticked, the more efficient the home will be.
• Climate. Depending on where you are in New Zealand, the local climate will make a big difference to your design choices, especially around insulation levels, air tightness, moisture control, material durability and more. Solar can help make your home more energy efficient even in a Dunedin winter, but there will be differences in the impact the local climate will have on solar generation.

Choose the right design

Solar power works at its best when it's paired with the right energy efficient home design. Going above and beyond the bare minimum to pass CCC makes a huge difference to the liveability - and ongoing costs! - of any solar-powered home.

• Good insulation for the foundation, attic and walls.
• Framing with good thermal resistance and thermal bridging.
• Well-sealed for air and heat envelope.
• Double- or triple-glazed windows.
• Smaller sized homes are easier and cheaper to keep liveable.

Build in the right direction

The orientation of a home’s roof makes a huge difference to the efficiency of solar panels and other aspects of an energy efficient home.

• Northern orientation. The sun rises in the east and sets in the west, tracking along the north as it goes in the Southern Hemisphere. Solar panels work their best when they are placed facing the sun, to gather as many solar rays as possible. 
• No shade. Shade kills solar power efficiency, so ensure there are no trees to block the sun from hitting your home. Think ahead - small trees can become large trees, and future multi-storey buildings could block your solar access too. Check council plans as well as zoning and land use regulations to consider your risks.
• Passive solar. Solar panels aren’t the only way to benefit from the power of the sun. Place living areas and windows on the northern side of the home to allow the sun to heat these spaces naturally, reducing the need for heating and cooling devices during the day.

Choose your solar system

There are 3 main types of solar system suitable for your newly built home.

• Grid-tied. This is the most simple solar power system, made up of a set of solar panels and a solar inverter. It ties directly into your power grid and replaces some of the power you draw from the grid.
• Hybrid. Hybrid solar power systems are more complex, with the option of including a solar battery or set of batteries. The addition of the batteries means that you can continue to use your solar power even when the sun isn’t shining, such as at night or during a cloudy day.
• Off-grid. The most complex and powerful solar power system. These are designed to completely remove your need for the main power grid, powering your home completely through solar panels.

Each of these systems vary in size, depending on your power need, but all of them can help you create an energy efficient home.

What system should I pick?

Every family and every home is different, so it’s best to speak with an expert to get an idea of your needs and the system that’s right for you. We’ve found that most homeowners choose a grid-tied system, but new home builds have a lot of opportunity to go for more complex and powerful options, integrating them into the design from the get-go.

Heat your home 

Energy efficient homes benefit from an equally efficient heating system! Solar power can fuel any kind of heating solution you may want for your new home, as long as it relies on electricity. This includes heat pumps, which are generally considered the most energy efficient heating solution, and can provide cooling options as well.

Best of all with a new build is the ability to design a temperature control system that’s holistic, designed specifically for your family’s and home design’s needs. This means fewer compromises on heat pump placement - you can pick where it goes before other factors get in the way.

Remember, solar powered heating works best when it is combined with effective insulation design and materials. Ensure that your energy efficient home has excellent insulation in the windows, walls, roof and foundation to get more out of your system.

Heat your water

Water heating can often be one of the most expensive utility bills you can have, even with an energy efficient home. The right solar power system can help reduce that bill with a solar diverter.

Solar power can power any electrical appliance in the same way as the mains can. This includes water heaters, like swimming pool warmers and boilers. A solar diverter in your home means these power-hungry devices always have some solar power set aside specifically for their operation. 

These can work with any kind of water heating device you choose for your energy efficient home, as long as they are electrically powered.

Power your vehicle

Make your home truly energy efficient with a plug-in hybrid or electric vehicle charger. 

EVs of all descriptions are becoming more and more popular in New Zealand, particularly with the new rebate offered by the NZ Government. Chances are, if you don’t already have an electric vehicle, you may want or need one in the near future. Best to design ahead!

A vehicle charger in the garage of a solar-powered, energy-efficient home is the same as a vehicle charger in a typical home. Simply plug your vehicle in to allow it to charge. They are best paired with solar power systems that have batteries, allowing you to charge your vehicle overnight without having to draw on the grid.

You won’t need a huge system to power your vehicle either. Even a small system can provide enough power to completely charge an EV, depending on the season.

Do solar panels make your home more energy efficient?

There are many factors to consider when building an energy efficient home. Location, design, materials and technology all contribute to how much - or how little - energy a home requires. Solar power is a huge and increasingly important part of that calculation.

Solar panels and an accompanying solar power system can help reduce a home’s impact on the environment as well as the utility bills, and they work at their best when placed in a home with energy efficient design in mind.

For more information on incorporating solar power into your new home design, get in touch with the expert team at ZEN Energy.