Now HouseToronto, Canada
The first Now House ® project in the city of Toronto demonstrates the transformation of a typical older house into a near-zero energy structure. This is the first demonstration of the Now House ® process which can convert millions of existing houses into the energy-saving homes that are required for modern times.
Typically, ideas for green buildings involve designs for new construction, but approximately two-thirds of the homes that will exist in 2050 are already standing. Because of the large proportion of energy consumed by homes, and the resulting greenhouse gas emissions, improving existing homes is one of our biggest environmental opportunities. It is also quite challenging.
For the renovation of this modestly-sized, sixty year-old house, the focus was on conservation. The design was simple: reduce heat loss, keep what isn’t broken, and replace only those things that provide maximum gain. Nonetheless, it involved every aspect of energy-conscious design and living: demand reduction, equipment efficiency, and on-site renewable energy sources.
Energy Demand Reduction:
The insulation of the exterior envelope of the house was improved all around. Insulation was installed at basement walls and floor slab where none had existed before. An additional layer of insulation was added to exterior walls – the walls were made thicker. Older, inefficient windows were replaced with modern insulating units. So-called “low-E “(for emissivity) glass in the windows helps keep heat indoors in winter, and outdoors in summer. Attic and roof insulation were improved as well.
Replacing the main south-facing window with a larger one increased natural daylight in the living area, decreasing the need for electric lighting. It also provides passive solar heating in winter. All light fixtures in the home were changed to more efficient compact-florescent bulbs, reducing electrical consumption. To reduce standby power use, power strips with “kill switches” are used that make it easy for occupants to turn off all computers, small appliances, cell phone chargers, and the like. All major appliances were replaced with ENERGY STAR rated models (where possible – not all types of appliances are rated), which helps reduce the use of water, electricity and gas.
Low-flow faucets, shower head and water saving toilet reduced water use as well as the amount of gas used for hot water.
Equipment Efficiency: The heating and hot water systems were upgraded in several ways to increase efficiency and also to recycle waste heat. A new high-efficiency air handler (the main fan that delivers heated air) with a variable speed motor
will cut energy costs and improve the comfort level of the home. Also. a special heat recovery ventilator is used that exhausts cooking and bathroom odors, humidity and stale air from the home, captures the heat from that air, and uses it to warm the fresh air that is brought in from outside.
The basement floor slab is heated with an efficient in-floor radiant system (warm liquid is circulated in pipes inside the floor slab). This increases the comfort in the basement, and the heat will slowly travel up through the home, reducing the amount of heat needed on higher floors.
A central water storage tank stores heat from all sources. This includes heat from solar panels and from equipment that captures the heat from water draining from the shower, sinks and dishwasher. A tankless “on demand” water heater will add only the amount of heat necessary to supplement the on-site sources.
On-site Energy Sources: In addition to the recycling of waste heat from exhaust air and wastewater, the house uses two types of solar panels on the roof. Two solar hot water (or solar thermal) panels are used to heat the basement floor in winter, and all other heat from these panels is stored in the hot water tank. This reduces the need for natural gas or electricity to provide heat for hot water and home heating.
An array of sixteen solar photovoltaic (PV) panels is used to provide electrical power from the sun. Just like a typical house, the Now House ® is connected to the local utility grid that provides electricity from outside. Unlike the usual “net-metering” arrangement in most U.S. localities, in this case all of the electricity produced on-site is bought by the utility, and at a very attractive price that allows the revenue to offset all of the house’s energy cost. Therefore it is a “net-zero energy cost” house. The Now House ® pays its own energy bills!
The Now House ® achieves a near-zero energy use status. Natural gas use has been reduced 78% through demand reduction, equipment efficiency, and the solar thermal system. Solar-produced electricity is sold to the utility, offsetting the remaining cost for gas, meaning the home is heated, ventilated, illuminated, and provided with convenience electrical power and hot water for no cost!
In reducing energy consumption, the house has reduced its contribution of greenhouse gas emissions by 59%, or almost 6 tons per year. Electricity use is reduced by 60%.The Now House ® has demonstrated that energy independence is possible for existing single-family homes, even in a cold climate. Its energy-efficient features are supplemented by a variety of green building strategies – improving comfort and health by improving indoor air quality and daylighting, and employing non-toxic materials; conserving material resources by minimizing demolition, re-using materials and recycling waste; and conserving water. The “triple bottom line” of green building – environmental benefit, economic benefit, and health & welfare benefit – is apparent in the Now House ® project!
Courtesy Work Worth Doing and The Now House ® Project Inc., Toronto. www.nowhouseproject.com
Now House® is a registered trademark of The Now House ® Project Inc.