Making houses, schools and other buildings energy efficient (AND ENERGY ZERO)


Zero Energy BuildingsZero energy Homes, Schools and other buildings

Soon all new buildings will be energy zero.

California, the European Union, Japan and several Chinese jurisdictions have ambitious Zero Energy Building projects for the next decade.

Zero Energy Buildings are within our reach. They aren’t a distant or a too expensive green dream. Zero Energy Houses are healthier, more comfortable and their up-front additional costs are  paid back in a few short years with energy savings.

Zero energy buildings
Passive Solar Houses

Houses and Other Buildings energy Consumption

Our homes (and other buildings) waste a prodigious amount of energy.

America’s buildings consume more than 70% of the electricity and around 35% of the natural gas used in the country. They are the largest single contributor to CO2 and other harmful gas emissions.

The average American household spends more than $2.000 per year in electricity and gas - more than $100.000 over 50 years.

But it hasn't to be this way. If you are building or buying a new house, you can reduce energy bills to a small fraction.

Low and zero energy buildings do not mean privation or less comfort.  On the contrary.

An Easy way to make Energy Savings in your House: efficient appliances

Domestic appliances and electronics consume about 40-50% of the average household electricity consumption. A lot, indeed!

But new efficient refrigerators and freezers can cut refrigeration costs by as much as 50% or more. And the same is true for clothes dryers, dishwashers or clothes washers…

See: Energy Efficient Appliances and Electronics

Super-Insulation and Air-Tightness

Smart home design and very high levels of insulation and air sealing are key to reduce residential energy consumption and improve thermal comfort.

Insulation Guide for home energy improvement
Home Air Sealing Guide

Buildings energy consumption in the US:
about 80% of the electricity and 35% of the Gas

Buildings and climate change

Many dozens of infographics here

Ideas for energy efficiency ideas

In new construction and large scale renovations consider:

- smart house design and proper, orientation, size, shape and layout;
-very high levels of insulation and airtightness;,
- high-efficient windows and exterior doors,
- energy efficient appliances and electronics,
- energy-efficient lighting,

See: New Houses guidelines

"Small" home energy improvements:

- metallic window films;
- small sealing and insulation projects;
- zoning and thermostats
- energy efficient appliances and electronics
- switch off or unplug electronics and appliances as much as possible;
- new energy efficient lights,
- low-flow rate faucets and shower head,
- strategies involving ceiling fans and the settings of air conditioners.

most fundamental principle of home energy efficiency

We don’t need super-smart houses or technological breakthroughs to sharply reduce our energy consumption and to minimize energy waste.

We can’t forget the most fundamental principle for energy efficiency: it’s a lot easier and cheaper to make basic energy improvements than to produce energy.

It’s a lot more advantageous - from an economical and environmental standpoint - to save energy by insulating and air-sealing your house, or by using low energy appliances and lighting systems, or by implementing a smart house design, than by producing energy – even if the energy comes from renewable sources.

At a macroeconomic level, energy improvements are a business of many millions of dollars, or even trillions. And the future of the energy sector, and the role of solar, wind and other renewable sources of electricity, depend largely on energy improvements in buildings.

The Golden Rule For House Energy Improvements

30 Misconceptions about House Energy Improvements
20 Commandments for Home Energy Improvements
Design, Architecture & House Construction
Working and finding construction professionals
First Priorities When Building a New House or Making a Big Renovation

Contents Top

House-Energy savings estimation tool

Want to know how much energy you can save in your house by using new energy efficient appliances, new lighting bulbs, new windows and exterior doors, higher levels of insulation, metallic window films, ceiling fans and more... much more?

See: Energy Savings Estimation Tool

Family expenditure in energy New Houses, Schools and other buildings have to be more energy efficient

Our building codes establish minimum standards for energy efficiency, but they are not high enough. Building codes have failed – and are still failing – to provide guidance on low-energy construction.

Energy auditors often complain about homeowners: “We go back to the same houses, and make the same recommendations that are never implemented” - a fact that shows how important can be your motivation and commitment on such an important issue.

New Houses Guide
Tell your Mayor that you Support Green Building
Rating your City Green Building Programs
Cities with Great Green Building Programs

Contents Top

House design: do not compromise

If building a new house, consider carefully its siting and shape, and its orientation to the sun. .

Wrong decisions will make your home less comfortable and less energy-efficient.

Also consider carefully the size of the house. Homes should be modest in size to be energy-efficient ; large houses are difficult to heat and to cool, and will have high electricity and gas bills. If possible, keep the size of your home around 2,000 square feet or less.

House Orientation, Shape

House Siting and Size for Energy Savings

Contents Top

hot climates & Cooling

If you live in a hot climate shade your window and walls as much as possible (and the ground around your house). Use trees and shrubs and also devices like awnings, shades and pergolas.

Do not underestimate shading. Shade and natural ventilation are key elements for energy savings. Consider breezes and outside fresh air to cool your house. Open your windows to breezes and use ventilation fans and whole-house fans to bring outside fresh air into your home.

Natural Cooling Guide
Cooling with Shade
Cooling with Ventilation
Solar Heat Gains Control

Contents Top

Saving energy with Ceiling Fans and Air Conditioners. They Can Work in Conjunction

Ceiling fans and air conditioners cool by distinctly different methods. But they can work in conjunction.

Each one degree increase (Fº) in your air conditioner thermostat setting can decrease your air conditioner bills by, say, 5%. And ceiling fans make that possible. Just turn your ceiling fan and raise the AC setting by 4ºF/3ºC or slightly more. You will not notice any loss of comfort.

You may use your air conditioner in conjunction with ceiling fans (or other circulating fans) to get energy savings.

Fans can be great for reducing cooling bills, and you should not underestimate that.

And do not forget whole house-fans (if you live in a hot climate with cool evenings); and small portable fans and window fans.

See: Ceiling Fans with AC

Contents Top

You May Not Need (Central) Air Conditioners

Central air conditioners are expensive to install and to run. But there are good alternatives to them, from an energy-improvement and environmental standpoint.

You can greatly reduce your cooling bills by using very energy efficient windows (and, metallic window films, in old windows), shading devices (overhangs, porches; awnings, blinds, shades, shutters), tree-shade and reflective roofing materials...

Air Conditioners Guide
Air Conditioners Alternatives

Contents Top

energy savings: Pay attention to electronic devices in Standby and Idle Mode.

Top energy wasters in our homes may be hidden or go unnoticed. Many home appliances have surprisingly high energy costs. Be aware.

Pay attention to refrigerators, clothes washers and other domestic appliances. But do not forget vacuum cleaners, personal computers, printers, routers and mobile telephone chargers and telephone answering machines; or CD players, video game consoles, grills, electric ice-cream makers, electric bread makers, electric juice extractors, electric knifes, electric egg boilers, electric toasters, coffee machines, hair-dryers, electric toothbrushes, electric razors, electrically powered towel rails, electric blankets, electric and more, much more…

That’s just a part of a much larger list. And though they aren't energy-intensive their large number makes them an important element of electricity bills.

See: House Electronics

Videos on Energy Improvement Strategies & Illustrated Stories About Energy and the Environment

We have edited 50 videos on Home Energy Improvement, in our YouTube channel. See a list of them here.
We have also dozens of illustrated stories and high quality images about low-energy and environmental issues that you can use freely on your site or blog. See their list here: Stories/Images List.

Contents Top

Saving energy in our homes with Heat Pumps: Electric Heating and Cooling

Heat pumps provide both heating and cooling at much lower prices that other electric equipment.

Depending on their type and features, they can produce 2, 3, 4... times more heat than the electricity they use, contrary to common electric-resistance heaters where this relation is 1 to 1.

They are a reliable technology, excellent for moderate climates. But which is their role in efficient homes, in cold climates?

See: Heat Pumps Guide

Contents Top

House Heating Savings & Furnaces Systems

A small furnace, properly installed and with a short and straight duct system, can provide significant energy savings.

That's the best option in very cold climates, in very large homes, or homes with conventional levels of insulation and without the design and the features required by passive solar houses. That’s a compromise solution, below the standards of low-energy homes.

Be aware. The duct system should be short and straight, and located within the thermal envelope of the house; the supply registers should run along interior walls and the equipment should not be located in attics, crawl spaces, or garages.

Besides, before buying a furnace you should seal and insulate your home. Ideally, you should insulate and seal it to very high levels, to keep heat loss to a minimum.

See: Furnaces Guide

Contents Top

Fireplace heating

Fireplaces Are Unhealthy and 90% of the Heat Goes Up Through the Chimney

There are dozens of millions of homes with fireplaces worldwide. Unfortunately they heat too little (90% of the heat goes up through the chimney) and they emit dangerous pollutants.

As the American Lung Association puts it: "Burning wood emits harmful toxins and fine particles in the air that can worsen breathing problems and lead to heart and lung disease and even early death"

See: Fireplaces and Heating Stoves Guide

Contents Top

Making your house more energy efficient with high efficient Windows & Tubular Skylights

Windows are a weak link in the thermal envelope of any house. They can be responsible for many thousands of dollars in energy costs, during their lifetime.

They are often the main responsible for high air conditioning costs in hot climates; and for a significant part of the energy loss in cold climates.

To prevent it, you have to choose the right type of windows, taking into account your climate, and to install them properly.

As to skylights, they can be great for natural lighting, but they can also increase your energy bills by several hundreds of dollars, every year. Don't be fooled by dreams of beautiful views at the top of your rooms.

Windows & House Energy Efficiency
Skylights Guide

Contents Top

Lighting Savings of About 75%

Lighting accounts for about 5%-10% of our energy bills. In the USA that amounts to $100-$200 per year/household...

But it's not difficult to reduce lighting consumption. New efficient light bulbs and fixtures combined with simple strategies, and timers, sensors and dimmers can easily cut home lighting bills in half or more.

Lighting Guide

Outdoor Lighting Guide

Contents Top

House Energy Audits

 Building codes establish minimum standards for energy improvement. But for many years they were too low, and they still aren't strict enough. Building codes have failed – and are still failing – to provide guidance on building.

And the end result is well known: millions of houses and buildings with very low levels of comfort and wasting energy.

In America, for instance, the average homeowner spends about $2.200 a year in electricity and gas. And that’s too much. You can cut your energy bills in half or more. A reduction of just 20% in such bills means $17.600 over a period of 40 years.

And that’s where energy audits enter…

See: House Energy Audits

Contents Top

Buying a New Energy Efficient House

Energy Star certified houses (EUA, Canada), 6-10 Star homes (Australia) and European homes with a A or B energy performance certification are a good choice for energy savings. But they fall short of the best.

See: Buying a House

Contents Top

energy savings: Electric vs. Gas Small Heaters

Gas is cheaper than electricity. The price of gas can be 1/2 or 1/3 of electricity, per unit of heat. Why then not use small gas heaters instead of small electric heaters?

One of the reasons is that unvented gas heaters are unsafe. On the other hand, electric heaters are cheaper to buy and to install.

That explains a lot. But vented wall gas heaters can be a great alternative to electric heaters, and since they have a larger capacity they can be used in other more ambitious heating strategies.

See: Small Electric and Gas Heaters Guide

Contents Top

Solar energy for our Buildings

Solar water heating is now part of millions of homes worldwide. On the other hand, much of the future of our planet relies largely on photovoltaic systems... 

But residential solar powered systems are not just photovoltaic systems for electricity generation and solar water heating systems. They include also passive solar and solar space heating.

See: Home Solar Guide

Contents Top

Selecting a Water Heating System

Water heating bills amount to $300 to $450 per year in most households. Water heating is one of our biggest energy expenses.

There are several types of water heaters to choose from: 1) Solar… 2) Gas tankless (condensing and regular); 3) Gas storage (condensing and regular); 4) Electric; 5) Integrated heating-water systems.

See: Water Heating Guide

Contents Top

Install Low-Energy Exterior Doors

If you are going to install new exterior doors consider low-energy doors. They may cost you a bit more, but can save you hundreds of dollars over their lifetime.

Be careful with patio glass doors and glass doors. They are affordable and may look nice, but that comes at a high cost. They are a major source of heat loss and gains; there aren't such a thing as efficient glass doors.

See: Doors Guide

Be Aware of Leaky and Un-Insulated Ducts  

That hidden and unnoticed network of tubes in the walls, ceilings or floors, carrying the air from your home’s furnace or heat pump or AC to the several rooms, can be a big energy waster.

Leaky and un-insulated ducts can add hundreds of dollars to the house energy bills of homeowners.

See: Home Ducts Guide

Contents Top

Home Moisture Problems

Keep excess moisture out of your home. Moisture is responsible for structural damages in walls, floors and attics, and for higher energy bills and serious health hazards.

Excess moisture reduces energy-efficiency, by increasing energy consumption. Your heating and cooling system will have to work harder and to use more energy to dry out your house; and when moisture condenses in the insulation materials, heat will flow more easily through them.

See: Home Moisture Guide

Roofs and Attics

The key job of a roof is to keep water out.

But it should also be low-energy, which means that the roof should also keep the heat out of our houses. Yes: keep the heat out… even in cold climates.

Roofs can’t ever be a significant source of useful heat gains. 

Roofs Guide

Contents Top

Walls guide for energy savings

Walls need insulation. Without it, heat will flow to the outside through the materials they are made from. Wood, steel, concrete and other construction materials do not impede heat flow. That's why houses with thick solid wood, brick houses/solid masonry walls can be so uncomfortable.

See: Walls Guide for Home Energy Improvement

Floors & Flooring

When building or renovating a home, when it comes to floors, people generally think of floor coverings or radiant floor heating…

Even if there are many people complaining that their floors are uncomfortable and cold, most homeowners and builders do not recognize the importance of floors for house energy savings, and they end up with buildings that are expensive to heat and cool.

Floors & House energy efficiency
Flooring Guide

Contents Top

House design and Efficiency & Basements

Many basements are a source of problems. If you are building a new home, consider another type of foundation in soils with poor drainage and high water tables, or in areas that have a high risk of flooding. And avoid crawlspaces; they are too prone to problems.

See: Basements Guide

Do Not Forget your Yard and your Pool

A single gas-powered leaf blower can emit as much pollution in one hour as dozens of cars operating for the same period of time. And typical gas mowers are responsible for about 5% of the world’s pollution, which is awesome.

Pay attention to your yard equipment efficiency, and also to your pool, if you have one.  

Many swimming pool owners keep their pool pumps running 24 hours per day, but limiting it to 3 hours per day can be enough.

Besides, the vast majority of the existing pool pumps are single-speed; they can’t change their flow rate; during most of the time they provide greater water circulation than necessary, wasting large amounts of energy.

And there are other conservation measures that can be implemented…

Swimming Pools Energy Improvement
Energy Efficient Yards

Contents Top


energy improvements Are a Powerful Tool For Creating a Better Environment

Take the example of furnaces and their huge environmental impact.

Each furnace emits on average 20.000-50.000 pounds of CO2 per year. Reducing such amounts by 30% - which is easy to get through conservation measures or by upgrading to a new multi-stage variable speed 90%+ AFUE furnace – equals to reduce the CO2 emissions by 90.000-100.000 pounds over the expected lifetime of the equipment (20 years or more).

And we can multiply the examples. Efficiency is a powerful means for creating a better environment and a better world.

Energy Improvements & Environment
The 2 sides of: CO2 and Home Energy Consumption

Renewables & Green Building & Green Homes

Solar water heating can provide energy savings of 80%, in hot and moderate climates. Photovoltaics can solve many of our environmental problems. Small wind powered systems can provide green electricity at low cost.

But in the short term, the most important from an economical and environmental standpoint is design, landscaping, insulation, sealing and high efficient appliances, windows, electronics and water heaters. Or tree shade, and overhangs and awnings, in the summer… Or solar passive gains in cold and moderate climates.

Passive solar techniques are often undervalued. Iconic technologies like solar photovoltaic systems are much more appealing. But that's wrong. Passive solar can provide exceptional results with very low or no costs (in new construction).

Passive Solar Guide
Residential Solar Photovoltaic
Solar Water Heaters Guide
Room Space Heating with Solar
Small Wind Systems Guide
Small Hydro Systems Guide
Green Electricity Guide

Contents Top

Landscaping for House Energy Efficiency

The landscape around your house is not just about privacy and good looks; it has also a great impact on your comfort and energy consumption.

Trees and hedges can provide shade but also protection from winds, or drive cooling breezes towards your home, or block street noise... If you are building a new home, to fully benefit from your landscape, consider improving it.

Trees and shrubs can redirect the winds away from your house, or bring refreshing breezes into it, or shade your roofs, walls and windows, or block unwanted sunlight, making your home and your yard more comfortable, and all this for free or almost free... 

See: Landscaping for House Energy Efficiency

Solar Kit for water heating
Save Energy, Save Money... Find the best ways for Home Energy Efficiency with us…






Contents Top