There is no recipe for the perfect net zero home, but there are principles that guide the design professional in creating a structure where all the components work together in a harmony of energy conservation and generation. Energy is conserved with an effective building envelope, efficient appliances and structural orientation while a source of renewable energy provides all the power you need for a clean energy slate. Here are the (arguably) five most important elements in creating an effective net zero structure.
Passive solar design
The orientation of the structure is key in keeping heating and cooling costs down. Valuable solar heat gain in the cold winter months can reduce heating costs while orienting the structure to reduce heat gain can have a positive effect on cooling structures in warmer climates. Orienting the structure properly and ensuring that the doors and windows are correctly placed will help to create a building that isn’t excessively hot or cold. Coupled with a high-performance building envelope, your heating and cooling costs can be dramatically reduced.
Effective building envelopes
These can be attained by providing high-performance insulation in wall, floor and roof systems. The most effective method of insulation is through utilizing insulated concrete forms (ICFs). Here a concrete core is further insulated by an outer layer of EPS. Cost effective, strong, sustainable and environmentally friendly, Insulated Concrete Forms (ICF) construction is a superior way to build. ICF wall systems need to be combined with effective roofing insulation and super-insulated doors and windows. Flooring also needs to be comprehensive to guarantee a high overall R-value.
Energy efficient appliances
Another very effective way to reduce consumption is through Energy Star appliances. These appliances utilize far less energy than their conventional counterpart and are widely available. A big contributor to energy consumption (especially in commercial buildings) is lighting. Using energy-efficient lighting such as CFLs and LEDs will significantly lower consumption. Net zero homes will also rely on natural sunlight to penetrate those areas of the structure which enjoy the most use. Occupancy sensors will adjust heating and cooling systems as well as lighting to prevent unnecessary energy use.
Energy audits and user monitoring
Even the most sophisticated systems still rely on the participation of building occupants if they are to work effectively. Here education and monitoring will help the occupants to modify behavior and tweak components of their net zero home to optimize their energy efficiency. A home energy rater or building science expert can help to balance the elements of the design to ensure that the structure will reach its efficiency targets. These design experts will determine which materials and components will cost the least and provide the highest return. They will navigate between budgets and energy efficiency to help you get the most bang for your buck. These experts are able to perform blower door tests and other measurements to ensure that the workmanship is up to par and that your home or building is as well insulated as you would like. Even the most insulated materials will be rendered moot by poor installation.
Renewable energy source
No matter how efficient your structure is, it will still need some energy to operate. This can very effectively be provided by a large choice of renewable energy sources like wind, geothermal, solar and biomass. Which energy source you choose depends largely on the resources available on the site, the orientation of the site and the cost.
Every location and build is different and there is no foolproof recipe for net zero success. Each design professional and builder will have methods which they prefer, so choose construction professionals with proven track records. Do your homework and don’t be afraid of spending a little more on initial construction for a net zero home as they offer exceptionally good returns on investment and increase the value of your property; it’s one of the best investments you will ever make.