The energy crisis, whose first signs appeared in the 1970s, has had important consequences on the laws of many countries. If initially the policies aimed only at reducing heat losses, at present times we talk about the use of all renewable energy sources in the environment, to make a building reaching a greater autonomy. This is what the “passive house” concept is all about.
At the level of the roof, the requirements are aimed at improving the thermal insulation and transforming the roof into a complex system, which also includes equipment for harnessing solar energy (for hot water and electricity – photovoltaic panels). More and more manufacturers of roof systems also include photovoltaic panels in their offers, some in the flexible version, while others designed as photovoltaic shingles, able to replace the traditional cover materials. The best thing to do is discuss roofing options with Lawrenceville roofing pros. They will be able to give you expert advice to make sure whatever roof you choose matches the needs of your home and budget.
The roof of a passive house can help you save money
The architecture of the roof of a passive house does not differ much from a classical roof, but they typically have a more compact form (compact form translates into better energy efficiency) and are south-oriented, in order to benefit as much as possible from the heat from the sun. Attic windows as well as roof slopes are very important details to take into account.
Due to its special construction, the passive house is very little sensitive to changes in the meteorological parameters, from the point of view of thermal comfort, which is respected even at the roof level. In principle, all opaque elements must be insulated so that the overall coefficient of heat transfer does not exceed 0.15 W/ mpK. Also, the roof of a passive house must be sealed against uncontrolled air transfer with the outside environment.
The green roof
One of the solutions you have if you want to improve the energy-efficiency of your house and save money on the energy bills is to install a green roof. The green roof is a modern, environmentally friendly roofing system, covered with soil that allows vegetation to grow on its surface. These habitats with urban vegetation contribute to the thermal insulation of buildings, lowering the costs for heating in the cold season, and for cooling in the summer.
The green roofs also reduce the amount of urban heat, mitigating the greenhouse effect and leading to an increase of the lifespan of the roof and of the value of the building in general.
Green roofs have a higher efficiency in single-level buildings, especially if rain water management is also used efficiently. The aesthetic or functional factors can be influenced by the budget limitation but also by the structure of the building.
The green roofs are classified in extensive and intensive, depending on the thickness of the planting environment and the effort required for maintenance, the variety of plants used and the cost of realization.
As you use the energy produced by a photovoltaic system, the energy bills will decrease. How much you save with solar energy depends on the size of the PV system, and the power consumption. In addition, not only do you save on your electricity bill, but if you generate more electricity than you use, the surplus will be exported back to the grid and you will be compensated for this production (given that your photovoltaic system is connected to the electrical network).