When walls and ceilings of a house are poorly insulated, with low temperatures outside, they are cold to touch. When there is no insulation or it is poor, it is easy for water to condense on surfaces, so damp and mold on walls and ceilings may appear.

When all windows and doors in the house are closed, you should not feel cold drafts anywhere, and if there are, the draft should be light. Air leaks (air intake from outside) usually occur next to windows and doors, shutter boxes, or through sockets. An easy way to check it is to lit an incense stick and see if the smoke drifts. Another way is to pay attention to a potential “hiss” caused by air intake.

Gray water recycling systems collect the water used in sinks, dishwashers, bathrooms and showers, clean it and use it for the toilet, dishwasher or the external irrigation faucet. 
Rainwater storage systems are a simple way of collecting rainwater, traditionally placed on rooftops, for later use in homes, as an alternative to the drinking water supply and thus, and for reducing consumption in the traditional water supply system.

Remember that there are normally 5 containers available, each of them is identified with a different color, for example: organic waste, plastics, paper, glass and others.

Eco-friendly paints or water-based paint have been specially designed to emit very low levels of volatile organic chemical components (VOC). To make sure about it, check the label indicating if containing a low level or no VOC, also see if it is certified by an environmental institute, it must include an organic paint seal or, and you can also check components (see that it does not contain heavy metal-derived pigments or petroleum).

Natural ventilation depends on the tightness of the house, the outside temperature, the wind and other factors. Therefore, in a warm climate, some houses may not have enough natural ventilation to eliminate all pollutants. On the other hand, well-insulated or sealed houses may have insufficient natural ventilation almost all the time, while others with air filtrations may have high energy costs. Ventilation handlers can be used to improve the effectiveness of natural ventilation. You can improve general ventilation (added to natural or full) by removing air pollutants and/or from the source of humidity. This type of ventilation includes the use of extractors placed in kitchens and bathrooms.

The term "chemical fertilizer" refers to any substance based on synthetic components specially created to favour crop yield. Some of them are ammonium sulfate, ammonium phosphate, ammonium nitrate, urea, ammonium chloride, and others. Organic fertilizers are derived from the remains or of living organisms. A pesticide is any substance used to kill, repel, or control certain plants or animals considered as pests.

Organic products are well-known to be safe and efficient. They are made from natural ingredients and are chemical-free stuff.