How can a home be renovated to be greener?

• What can homeowners do to reduce their energy use?
• How can homeowners conserve water?
• What other tools are available to green a home?

Energy Reduction

Homeowners can significantly reduce the energy consumption of a building by reducing heat loss and gain through the building’s envelope—the exterior walls, floor, and ceiling of the home—a using insulation, air sealing and efficient windows and doors.

With a better sealed and insulated envelope, these homes require a much smaller heating and cooling system and may operate this equipment for fewer hours each day.

It is therefore recommend that homeowners complete all of the ‘envelope’ retrofits and upgrades they intend to do before commencing any heating or cooling system upgrades or changes as the improvements made to the tightness and efficiency of the building envelope will reduce the required capacity of the heating/cooling system.

Common Energy Retrofits

Added Insulation
One can increase the comfort of a home while reducing heating and cooling needs by up to 10% by investing in proper insulation and sealing air leaks.

Draftproofing – According to BC Hydro Power Smart:

You can check for leakage yourself by holding two or three lighted sticks of incense in front of potential leakage areas. Powerful leaks will cause the smoke to dissipate and the tips of the incense to glow. Slower leaks will cause the smoke to trail away or move toward the leak. Or simply hold your hand in front of potential leaks on a cold day and feel for drafts. Either way, leaks are most noticeable on cold windy days. The most effective way to detect air leakage sites is to have a qualified contractor perform a “blower door” test.

Correcting air leakage sites through the use of caulking, weatherstripping or other measures can save a substantial amount on your heating and cooling bills without requiring outside help. Reducing air leakage can help lower energy bills and improve comfort. It's the single energy improvement that has the fastest payback on the investment.

Ventilation - As one increases the tightness of a home, by replacing or upgrading windows and doors and weather sealing, the potential for indoor air quality problems such as humidity and particulates from indoor combustion (gas or wood burning appliances) also increase. Mechanical ventilation using ENERGY STAR bathroom fans with timers or dedicated heat recovery ventilation (HRV) systems are two of the measures to address these potential problems.

Heating Systems - Residential furnaces work best when they are properly sized. A furnace that’s too large will cycle on and off quickly, with some inefficiencies of operation. This can lead to rooms furthest from the furnace remaining cool or to furnace chimneys deteriorating due to excessive condensation. As well, some of the furnace controls or parts may break down sooner than expected due to a high cycling frequency. 

Furnaces that are undersized may not keep the house at a comfortable temperature in the coldest parts of the winter. It will take much longer for an undersized furnace to bring a house back up to temperature after the thermostat has been turned down for a period.

Maintenance of your furnace can result in 10-15% reduction in energy consumption.

Cooling Systems - In some parts of BC, home cooling accounts for a significant percentage of summertime energy use. You can cool your home with many techniques that don't require ongoing energy use or expensive equipment. Before you consider air conditioning, consider alternatives that can keep your home cool while saving energy and money. 

Heat Pumps - Heat pumps provide continuous inputs of high volume, heated air into your living space, making them a very comfortable, efficient heating source. Since the temperature of the air they add to your living space is lower than that of an oil furnace, and they run continuously (as opposed to switching on and off like an oil furnace), you greatly reduce the hot/cold cycling and have a consistently warm home. Heat pumps work best when they operate most of the time during the heating season. They do require a backup system, so you can use a furnace as backup.

Domestic Hot Water Heaters - A solar water heater reduces the amount of fuel needed to heat water, because it captures the sun's renewable energy. Many solar water heaters use a small solar electric (photovoltaic) module to power the pump needed to circulate the heat transfer fluid through the collectors. The use of such modules allows the solar water heater to operate, even during a power outage.

Water Conservation

Installing a water-saver flush kit in a toilet saves thousands of litres of water per year. Replacing large-volume toilets with units that use only six litres per flush reduces water usage by 70% or more.

The engineering of low flush and dual flush toilets has come a long way in the past several years. Well-designed low flush toilets can retail for as little as $100. Dual flush toilets that give the user the option of a three- or six-litre flush are also available.

The average showerhead has a flow rate of 5 gal/min. A low flow showerhead should have a flow rate of 1.6 gal/min., giving total water saving due to bathing of 30%. Assuming the supply temperature of the water is 130 degrees F, hot water makes up 65% of the supply water to the shower, which equals a 20% saving in hot water, and the energy to heat this water.

Investing in Water Conservation

Water conservation has important benefits for protecting ecosystems and watersheds and for building better communities. In September 2010, BCREA worked in consultation with econnics – Eco-Efficiency Specialists to measure the value of homeowners investing in conserving water. A report on the study findings, Costs and Benefits of Homeowner Investment in Residential Water Efficiency Technology in British Columbia, was prepared by econnics and summarizes in detail what the positive effects, costs and benefits are of saving water and what homeowners can do to conserve water in their homes.

Healthy Retrofits

As energy efficiency of homes increases, issues such as indoor air quality problems as mentioned above may arise. There are many steps to take while undergoing renovations and retrofits to improve the healthfulness of homes, such as these offered by the Canada Mortgage and Housing Corporation.

Tools

Keeping the Heat In - This book tells you how to go about retrofitting your home. It deals with houses of all kinds in all parts of Canada, and not apartment or commercial buildings.

Retrofitting a house is simply upgrading it to keep the heat in. This means adding insulation, caulking and weatherstripping, improving or replacing windows and doors, and improving the heating system. Retrofitting also means including energy-efficiency measures in all renovation and repair activities.

This book is designed to serve the experienced do-it-yourselfer and the novice willing to give it a try. It’s also a useful consumer guide for homeowners who intend to hire contractors to undertake retrofit work. It’s important to understand how a house works before starting any retrofit work. This will ensure the job meets expectations without causing new problems.

BUILDSMART is the Lower Mainland's resource for sustainable design and construction information. Developed by Metro Vancouver, this innovative program encourages the use of green building strategies and technologies, supports green building efforts by offering tools and technical resources, and educates the building industry on sustainable design and building practices.

Based on the five stages of a building's life cycle, BUILDSMART presents relevant green building information in the areas of:

• design strategies
• construction
• operation and maintenance
• retrofit and tenant improvements
• renovations 
• demolition/deconstruction

CMHC promotes the concept of Healthy Housing™ and offers case studies and related checklists. CMHC also offers case studies that describe options for saving energy in houses of specific styles and ages.

The Pharos Project seeks to define a consumer-driven vision of truly green building materials and how they should be evaluated in harmony with principles of environmental health and justice. The principles of the Pharos Project are transparency, comprehensiveness, independence, accuracy and fairness applied to analyzing the impact building materials have on human health, the environment and communities—during production, use and at the end of their useful life.

BC Hydro also offers tools for homeowners as part of its Power Smart program, including an analysis tool, an appliance and lighting calculator, and in-depth product information (Note: To access some tools, you must have an account with BC Hydro).

Related Services

Certified Energy Advisors

Light House Sustainable Building Centre - offers how-to guides, directories of green products, useful green building links and services. Services range from an initial assessment of your home to a comprehensive prescription for even the most ambitious renovation.