Energy efficient buildings provide environmental, economic, and social benefits. They have lower energy demands and costs over the lifetime of the building. Key aspects of energy efficient design include site selection considering sun exposure and wind; compact building forms oriented for maximum sunlight; insulation and ventilation optimized for heat retention and air flow; and use of passive solar features, energy-efficient materials, and renewable energy systems like solar heating. Water recycling and waste management systems also contribute to sustainability.
3. Goal 11: Sustainable cities and communities
Life time sustainability
Reduction in fuel and electricity bills cost
Low running cost on the building life cycle
Environmental friendly
4. • Lower energy demand
• Less operating costEconomically
• Less dependence on fossil fuels (Co2 emissions)
• Less pressure on the environment and resources
• Sustainable energy access
Environment
• Healthier for the individuals
• Natural healthy setting will increase people’s
productivity
Socially
5. i. Site selection
Distance from basic services
Low altitude winter sun spot (passive solar heating)
Natural wind shelters (less heat loss)
Renewable energy potential spots
6. ii. Building form and orientation
Compact building (A/V ratio)
Longer sides facing the south (light, heat)
Projects like bay and dormer should be kept to minimum
Pitched roofs towards the south for solar collection
iii. Energy assessment
What kind of energy will be used? Solar? Bio?
Calculation of consumption and compare alternatives
7. (i) Insulation:
Both ceilings and floors
Avoid thermal bridges (more heat loss, condensation)
(ii) Ventilation:
Adequate openings to
assure efficient natural
ventilation
Mechanical ventilation
with heat recovery
8. (iii) Passive solar features
Avoid increased south facing glass areas
Choose windowns with low emissivity
Choose double glazing to reduce heat loss
Well fitting curtains on glasses
(iv) Building material
It should have least environmental impact
Long life and durability
Recyclable
9. Active solar heating systems (60% of a family hot
water need)
Hybrid system could also be implemented
10. Grey water recycle
Laundry and toilet flushing
Irrigation: nutrients (P,N ) excellent for the plants
Rain water harvesting
Waste management
Bio fuel
Compoting
Hinweis der Redaktion
Assuring sustainable use of the resources and savings for the building life time
Apart from reducing fuel and electricity bills, an energy-efficient building design can provide improved comfort for occupants while helping to protect the environment. It can also provide insurance against future increases in fuel costs. The aim of this paper is to provide broad headingsthat should be taken in consideration while building/ buying a building
- Distance from basic services: The energy consumed in driving in access to work places, schools, public transport routes could be reduced to the minimum when the site is perfectly being selected close to those services.
- Transmission of sunshine through windows (passive solar heating) can reduce heating costs. The selection of a site which is exposed to the low-altitude winter sun can allow for passive solar heating.
- Surrounding of height as a shelter from wind to reduce heat loss: Locations sheltered from the wind, heat loss from the building can be reduced. Shelter can be provided by nearby trees, adjacent buildings or surrounding hills. If no such shelter exists, it can be provided in time through planting trees or shrubs.
- Locations that are potential for renewable energy intervention: in a good location in terms of solar energy and wind energy exposure, or the ability to install underground bio fuel digester, to be used later in heating or power supply of the building
Building form and orientation:
A compact building (minimum surface-to-volume ratio), closer to rectangular shape is best for reducing heat loss.
Building form and orientation:
- A compact building (minimum surface-to-volume ratio), closer to rectangular shape is best for reducing heat loss.
- Adjustment of the longer facades facing south can allow for increased passive solar heating, day-lighting and natural ventilation which will eventually decrease energy cost.
- Projections such as bay and dormer windows should be kept to a minimum, since by increasing the surface-to-volume ratio of the building, they will increase heat loss. They also tend to be more difficult to insulate effectively.
Pitched roofs for solar collection: should have one slope oriented south to allow for optimum performance of a roof-mounted or roof-integrated active solar heating system.
Energy assessment:
Many decisions affecting the energy performance of a house are taken early in the design process. A method of calculating annual heating energy consumption should be used to compare alternatives at the preliminary design stage.
Building fabrics and structure:
Insulation
- High level of insulation should be distributed over all the building sides in roof, likewise on floor for example to minimize the heat loss. Higher level of insulation that required is economically justified on the long run.
- Avoid thermal bridges: Short circuit during insulations which leads to higher heat transfer resulting in an overall reduction in thermal insulation of the building and possible condensation problems.
Ventilation
Controlled vents should be installed in every room; slot vents incorporated in window frames can ensure a reasonable amount of continuous fresh air and can be opened up or closed down to a minimum as required.
Never seal up a house completely, as a minimum of fresh air is required for health and safety reasons.
A balanced ventilation system involving fans, ductwork and a heat exchanger can transfer heat from warm stale outgoing air to incoming fresh air (this is called “mechanical ventilation with heat recovery”). Stale air is usually extracted from rooms such as kitchens and bathrooms, and warmed fresh air supplied to living rooms and bedrooms.
Passive solar features
Avoid increasing south-facing glazed areas. Otherwise additional measures will be required to avoid overheating in summer and excessive heat loss at night and on overcast days in winter.
Windows should have a high resistance to heat loss. ‘Lowemissivity’ double glazing, which has a special coating to reduce heat loss, is required.
Well-fitting curtains can help to retain heat at night.
Building material
The building materials selected should have minimum environmental impact during their entire life cycle, including extraction, manufacture, use and disposal. Building components should be designed for long life and durability, and ideally should be recyclable at the end of their operating lives.
Heating systems (Solar)
Solar Active solar heating systems, including a solar collector on a south-facing roof, can contribute to heating needs with about 60% of a family hot water need. The system can be connected to backup conventional heating system.
Other points that should be taken in consideration
Grey water recycling system: recycling any domestic wastewater, including water coming out of sinks and showers, and excluding sewage. With proper treatment greywater can be put to good use. These uses include:
water for laundry and toilet flushing
Irrigation of plants: both food and nonfood producing plants. The nutrients in the greywater (such as phosphorus and nitrogen) provide an excellent food source for these plants.
Waste management: In the implementation phase, underground bio fuel reservoir should be constructed and all organic waste of the house should be thrown there. The gas produced should be compressed and transmitted in pipe lines for cooking purposes for example.
Organic waste also could be used as compost for home gardening