1. Choose an architect who understands energy efficient home design
  • Make sure builders are aware of your home’s low-energy goal.
  • Choose merchants who have knowledge and experience in energy efficiency
  • Remember that many architects / builders do not go beyond the minimum building standards and regulations, but the minimum is not the most efficient.
  • Minimize your heat loss:
    • Keep your house plan simple and compact – A house that is compact and without extensions will have less heat loss due to the reduction in external walls and roof area. Remember that single-story houses, such as bungalows, lose more heat through the roof than two- or three-story houses where rising heat is harnessed at all levels before reaching the roof.
    • External walls must have high-level insulation.
    • Ensure good draft-proof and controlled ventilation
    • Your architect can provide energy calculations of expected annual fuel bills.
  • Maximize Your Solar Heat Gain:
    • Build along the East-West axis – an energy efficient home will capture free energy from the sun to heat your home and water. Ideally, whenever possible, choose a location where your home can face the sun (external blinds can prevent overheating in the summer months) and be protected from prevailing winds.
    • Houses in the Northern Hemisphere should locate most windows on the south side with a reduced window size on the north side, and vice versa for homes in the Southern Hemisphere: most windows should face towards the sun to benefit from solar gains. However, some windows will need to be on the sunless side to allow good natural light in all rooms of your home.
    • Kitchens and breakfast rooms are mainly used in the mornings, so for houses in the northern hemisphere a southeast orientation will take advantage of the morning sun. For houses in the southern hemisphere, the northeast orientation will take advantage of the morning sun.
    • Hallways, stairways, and bathrooms can be located on the side that does not get a lot of sun, as they are used less frequently.
    • Locate living rooms and master bedrooms on the sun facing side
    • In two-story homes, consider having your bedrooms on the lower level (cooler for sleeping) and your living rooms on the upper level, further reducing your heating requirements as the floor above warms up.
    • Use the energy of the sun
      • Wind turbines can make the most of wind power generation
      • Heat pumps use energy from the sun – all renewable energy systems are complementary to the design of an energy efficient home.
  • Install an energy efficient heating and hot water system:
    • Renewable energy systems
    • Solar heaters
    • Use a condensing boiler if you use gas or oil
    • Install easy-to-use controls

    You can find more information about these on the Home Heating Solutions & Systems site.

  • Consider thermal mass

    • When thinking of an energy efficient home, remember that using certain materials will also improve your home’s ‘thermal mass’ by their ability to slowly absorb solar heat during the day and then slowly release this free heat at night – Materials Common used for thermal mass are:
      • Adobe bricks (mud or earth bricks)
      • Rocks and stones
      • Concrete (preferably concrete with stone)

      This is because they have:

      • High specific heat: capable of storing a large amount of heat for a long period of time, like thermal bricks in a sauna.
      • High density: basically the weight (mass) of a material in relation to its volume (its size) – the greater the mass per unit volume, the greater the density
      • Low thermal conductivity: slow absorption and slow release of heat.

    • Thermal mass is not insulation, it is the amount of specific heat that can be stored in a material (water has a high thermal mass because it can store a lot of heat). Insulation materials have a lower thermal conductivity to restrict heat flow and absorption.

  • Isolation
    • The percentage of heat loss from a house is approximately:
      • 42% Ceiling
      • 12% windows
      • 12% Unblocked chimneys and drafts around doors
      • 24% walls
      • 10% floor

    • So when you think about building an energy efficient home, understand that installing insulation at the construction stage is the easiest and cheapest way to improve the energy efficiency of your home.
      • You can upgrade standard half-timbered walls by using 140mm studs instead of 90mm studs; This will allow you more isolation. Masonry cavity walls can be enhanced by filling them with polystyrene foam insulation and using lightweight heat blocks.
      • It should have at least 250mm of insulation in the loft, 100mm of insulation between the joists, and 150mm of insulation at the top. Loft conversions require careful attention, especially if dormer windows are installed, but a high level of insulation can still be achieved.
      • Soil heat loss varies depending on the type of soil. However, the isolation of the ground floor is quite easy. Generally a 125mm polystyrene layer / sheet is used, this size will increase if underfloor heating is installed to minimize heat loss.
      • Make sure the insulation overlaps between the elements, for example between the wall and the loft / ceiling cavity.
      • Make sure air spaces, such as wall cavities, are free of debris that could bridge and compromise the insulating air space.
      • Make sure the fiber insulation materials are not compressed (tightly packed) as this will undermine their ability to properly insulate
      • Make sure all insulating materials are kept dry
      • Be sure to seal all openings where utilities, such as water and gas lines, enter your home.

  • Windows and conservatories
    • You will always lose more heat through windows than through walls, especially single pane windows. To minimize heat loss through windows, double glazing with a “low-e” coating should be installed in all new homes.
    • Double glazing not only reduces heat loss, but also offers some sound insulation. With double glazing, the two panes are usually vacuum sealed. However, you can get argon-filled (gas-filled) and triple-glazed units that are worth considering if you can afford them.
    • Greenhouses can save you quite a bit of energy by acting as a buffer between the adjoining wall, trapping the heat from the sun, thus reducing heat loss from the room separated by the adjoining wall. To be effective, greenhouses should be located on the side of the house that faces the sun and preferably not shaded by trees or other buildings.
    • Properly placed greenhouses should not require permanent heating, but the doors that separate the house from the greenhouse should be double-glazed and closed when not in use.

  • Efficient home heating
    • A well-insulated home is a low-energy home, which means that the heating requirements of an energy-efficient home are lower than a similarly-sized home that is poorly insulated.
    • Your heating system must take into account:
      • Fuel source and availability
      • The time you will spend in your home: fast or slow response systems
      • Building Material: Half-timbered houses need to have sensible heating, such as radiators or air heat pumps, as wood retains less heat than concrete, for example.
      • Underfloor heating systems are not suitable for houses built with lightweight building materials, such as wooden structures, due to their slower heating response.

    • You can have hydronic underfloor heating systems (wet or water-based) combined with radiators. These are typically designed with underfloor heating on the ground floor and radiators located on the upper floor.

    • Solid tile floors work best with underfloor heating. If you prefer a softer floor finish over tile, you should consider rugs rather than fitted rugs for better heat transfer / outlet within the room.

    • Renewable energy systems such as heat pumps and solar heating are perfectly suited to energy efficient home designs.

  • Ventilation
    • Ventilation is an important aspect that should not be overlooked as it provides fresh air and removes stale air and moisture. Removing moisture prevents the growth of bacteria and thus maintains a healthy living environment.
    • Kitchens must have extractors or passive chimney ventilation (PSV). The PSV works on the principle of “rising” hot air that carries the stale air up and out.
    • Heat recovery mechanical ventilation systems offer filtered air and reduced noise intrusion as windows can be kept closed. However, unless you are using a renewable energy system like photovoltaic (PV) or wind turbines, the energy required to run the fans rules it out as a feature of an energy efficient home. Also, for a heat recovery system to work efficiently, the house must be well sealed.
    • All rooms must have drip ventilation, which allows air to enter at a drip rate to provide the required room air change rate per hour (ACH).

  • Lighting and appliances
    • These should have a low power (low voltage) rating, saving you money on running costs and helping the planet by reducing CO.two emissions.

    So now you can save the planet and save operating costs by building an energy efficient home.