You’ve chosen the perfect site for your new home, but now you’re indecisive. Building “green” sounds noble (who doesn’t want to help our planet and create a healthy environment for our children?) but it also sounds expensive, difficult and confusing. If you’re like most people, you probably assumed that a green home is a simple assemblage of eco-friendly products like reclaimed wood, bamboo flooring, and odorless paint, but in fact, choosing products like these is only a small part, and perhaps the least important of sustainable building. To demystify what it means to build green, we need to start with a manual of basic principles such as those outlined by Andy Engel in tools of the trade – what I like to think of as the Seven Green Building Blocks.
But first, a definition: What is a green house? A green or sustainable house is one that is built and operated with a reduced impact on the environment through the efficient use of resources and that provides a healthy and non-toxic environment.
Green Building Block #1- house design
Here’s a surprise – the size, seat (sun orientation) And form of your home have the biggest impact on how energy efficient you will ultimately be.
- The bigger your house, the more materials it will take to build and the more energy to maintain. This is your most critical decision. Resist the urge to go extra large.
- Solar orientation is the second most important factor in determining your home’s energy needs. This is called passive solar design. Try to place the longest walls of the house on an east-west axis. This will give your south facing windows sun in the winter and shade in the summer. You can also place your garage on the west side of the house or use a porch, roof overhang, or trees to shade the west walls.
- The simpler the shape of your house (think New England Salt-Box), the more energy efficient it will be. Protruding wings and bays augment the outer skin of the house and let heat from the core escape, just like our own fingers and toes.
Green Building Block #2 – Sustainability
Like our bodies, houses age, sag, and eventually collapse. Water and humidity are the two culprits for premature aging and the final disappearance of our home, starting with mold and ending with rot.
- Water can be kept away from the structure through proper design of drainage, gutters and downspouts, as well as the use of special rain protection walls.
- Moisture can be controlled through carefully installed and fully sealed window and door flashing. By minimizing air loss, it keeps moisture out and heat in, reducing energy costs by up to 20%. When moisture is no longer allowed to travel through the exterior walls, the danger of condensation on the framing is eliminated, extending the life of your home.
- Use paperless drywall to allow moisture to wick out of the wet drywall.
Green Building Block #3 – Energy efficiency
Your home uses energy such as electricity and gas for light, heat, or cooling. You can reduce your need for heating and cooling through passive solar design, which provides a kind of built-in thermal protection. But you also need to reduce thermal loss or leakage with insulation and air sealing. If possible, install your own power supply.
- Use insulation and building felt on walls, floors, and ceilings to reduce heat loss. Enclose cavities, such as areas behind showers and tubs, soffits, and recessed lighting with a moisture barrier to prevent heat loss.
- Seal all openings and cracks where air can enter or leave the house.
- Do not install HVAC ducts in unconditioned basements or attics – 20% of energy can be lost. Completely insulate the areas around your ducts and seal them completely.
- Lighting accounts for about 15% of a home’s energy use, but you can reduce that percentage in a number of ways. Replace inefficient incandescent bulbs with cooler, longer-lasting CFLs (compact fluorescent lights) or newer LEDs (light-emitting diodes). LEDs use 1/3 the electricity of CFLs and are more directional for task lighting.
- Cut down on energy waste by installing a home automation system with motion sensors to turn lights on and off when you enter or leave a room. A home automation system can also reduce your heating and cooling needs by automatically opening or closing window shades based on outside temperatures and lowering your thermostat at night and when you’re not home.
- Use low consumption appliances.
- If possible, invest in solar panels to generate much of the energy your home consumes. Your power company will even buy any excess electricity from you during times of low usage (like when you’re on vacation).
Green Building Block #4 – waste reduction
You can reduce excessive waste in 2 ways: by using materials more efficiently (and therefore needing less of them) and by reusing old materials. In any case, you help the planet and your pocket at the same time.
- Size your home sensibly. Design your house in multiples of four feet to meet standard drywall and plywood sheets. It will also drastically reduce scrap wood piles.
- Recycle and reuse building materials like old concrete and stone as a foundation for a parking lot.
- Be an avid recycler of glass, plastic, and metals in your home. Set up a compost bin to turn your food scraps into rich mulch.
Green Building Block #5 – water conservation
The goal here is twofold: You need to reduce the amount of water your family uses, but also channel rainwater that falls on your lot back into the ground.
- Use low-flow showerheads and toilets to reduce water use.
- Use automatic sprinklers with moisture sensors to regulate water use and prevent overwatering.
- Use native and drought tolerant plants.
- Use porous concrete pavers in driveways to allow rainwater to percolate into the ground and recharge aquifers.
Green Building Block #6 – indoor air quality
We already mentioned how proper sealing and insulation can prevent moisture and mold in your home, but an airtight home has its own problem: It traps all gases and vapors inside the home, polluting the air you breathe. formaldehyde from particle board and OSB exhaust gases; automotive paints, finishes and products add VOCs (volatile organic compounds); gas stoves and poorly ventilated gas appliances add carbon monoxide to the stew. There are two ways to purify the air and breathe better: use less toxic products and change the ventilation system.
- Use building materials like plywood instead of OSB to reduce formaldehyde buildup. Some rugs are not only made from recycled nylon, but are also VOC free. Adhesives, paints and natural floor finishes also offer zero emissions.
- Use a dedicated air supply for furnaces and hot water heaters to prevent gases from being blown back into the house.
- Install a heat recovery ventilation (HRV) system to bring fresh outdoor air into living spaces while extracting air from bathrooms, kitchens, and laundry rooms.
Green Building Block #7 – Organic products
We have already shown how using green products can make a difference to the environment and your health. With more and more green products to choose from, let’s rank the various types and shades of green on display.
- Products made from recycled materials: concrete made from fly ash (a waste product from coal-fired power plants), carpet made from recycled (and recyclable after-life) nylon, faux stone countertops made from recycled paper, glass, and cement.
- Reused construction materials: reclaimed wood, sawn wood, brick and stone.
- Products from sustainable resources: cork floors from the cork oak (also durable, acoustic and thermal insulating and hypoallergenic); fast growing bamboo bamboo flooring.
- Energy efficient products: solar panels, Energy Star appliances, home automation systems, CFL and LED lights.
- Non-toxic products (both in their manufacture and in their use in the home): low-odor paints and finishes, carpets and plywood.
With this manual in hand, you now know the difference between a CFL and a VOC. As you can see, the most critical decisions for a green home are made when you first sit down at the drawing board. Your dream home will be energy efficient, durable, and safe if you design it using the seven green building blocks. Your friends may turn green with envy.