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1. Information about zero energy building and
green buiding
Submitted by:
Karan Yadav (2732)
Chaitanya Patil (2755)
Shambhuraje Patil (2757)

2. INTRODUCTION
A Zero Energy Building (ZEB), also known as a Net Zero Energy (NZE) building, or a Zero Net Energy (ZNE)
building, is a building with net zero energy consumption, meaning the total amount of energy used by the building
on an annual basis is equal to the amount of renewable energy created on the site or in other definitions by
renewable energy sources offsite, using technology such as heat pumps, high efficiency windows and insulation,
and solar panels. The goal is that these buildings contribute less overall greenhouse gas to the atmosphere
during operations than similar non-ZNE buildings. They do at times consume non-renewable energy and produce
greenhouse gases, but at other times reduce energy consumption and greenhouse gas production elsewhere by
the same amount. Zero-energy buildings are not only driven by a want to have less of an impact on the
environment, but they are also driven by money. Tax breaks as well as savings on energy costs make Zero-
energy buildings financially viable. A similar concept approved and implemented by the European Union and
other agreeing countries is nearly Zero Energy Building (nZEB), with the goal of having all buildings in the region
under nZEB standards by 2020. Terminology tends to vary between countries, agencies , cities, towns and
reports, so a general knowledge of this concept and its various employments is essential for a versatile
understanding of clean energy and renewables. The IEA and European Union most commonly use Net Zero
Energy, with "zero net" mainly used in the USA

3. About Green Building
A ‘green’ building is a building that, in its design, construction or operation,
reduces or eliminates negative impacts, and can create positive impacts, on our
climate and natural environment. Green buildings preserve precious natural
resources and improve our quality of life.

4. There are a number of features which can make a building ‘green’. These include:
• Efficient use of energy, water and other resources
• Use of renewable energy, such as solar energy
• Pollution and waste reduction measures, and the enabling of re-use and recycling
• Good indoor environmental air quality
• Use of materials that are non-toxic, ethical and sustainable
• Consideration of the environment in design, construction and operation
• Consideration of the quality of life of occupants in design, construction and operation
• A design that enables adaptation to a changing environment

5. Optimizing zero-energy building for climate impact
The introduction of zero-energy buildings makes buildings more energy efficient and
reduces the rate of carbon emissions once the building is in operation; however, there
is still a lot of pollution associated with a building's embodied carbon. Embodied carbon
is the carbon emitted in the making and transportation of a building's materals and
construction of the structure itself; it is responsible for 11% of global GHG emissions
and 28% of global building sector emissions. The importance of embodied carbon will
grow as it will begin to account for the greater portion of a building's carbon emissions.
In some newer, energy efficient buildings, embodied carbon has risen to 47% of the
building's lifetime emissions. Focusiong on embodied carbon is part of optimizing
construction for climate impact and zero carbon emissions requires slightly different
considerations from optimizing only for energy efficiency.

6. Advantages
• isolation for building owners from future energy price increases
• increased comfort due to more-uniform interior temperatures (this can be demonstrated with comparative isotherm maps)
• reduced total cost of ownership due to improved energy efficiency
• reduced total net monthly cost of living
• reduced risk of loss from grid blackouts
• Minimal to no future energy price increases for building owners reduced requirement for energy austerity and carbon emission taxes
• improved reliability – photovoltaic systems have 25-year warranties and seldom fail during weather problems – the 1982 photovoltaic
systems on the Walt Disney World EPCOT (Experimental Prototype Community of Tomorrow) Energy Pavilion were still in use until 2018, even
through three hurricanes. They were taken down in 2018 in preparation for a new ride
• higher resale value as potential owners demand more ZEBs than available supply
• the value of a ZEB building relative to similar conventional building should increase every time energy costs increase
• contribute to the greater benefits of the society, e.g. providing sustainable renewable energy to the grid, reducing the need of grid
expansion

7. Disadvantages
• initial costs can be higher – effort required to understand, apply, and qualify for ZEB subsidies, if they exist.
• very few designers or builders have the necessary skills or experience to build ZEBs
• possible declines in future utility company renewable energy costs may lessen the value of capital invested in energy efficiency
• new photovoltaic solar cells equipment technology price has been falling at roughly 17% per year – It will lessen the value of capital
invested in a solar electric generating system – Current subsidies may be phased out as photovoltaic mass production lowers future price
• challenge to recover higher initial costs on resale of building, but new energy rating systems are being introduced gradually.]
• while the individual house may use an average of net zero energy over a year, it may demand energy at the time when peak demand
for the grid occurs. In such a case, the capacity of the grid must still provide electricity to all loads. Therefore, a ZEB may not reduce risk of loss from
grid blackouts.
• without an optimised thermal envelope the embodied energy, heating and cooling energy and resource usage is higher than needed.
ZEB by definition do not mandate a minimum heating and cooling performance level thus allowing oversized renewable energy systems to fill the
energy gap.
• solar energy capture using the house envelope only works in locations unobstructed from the sun. The solar energy capture cannot
be optimized in north (for northern hemisphere, or south for southern Hemisphere) facing shade, or wooded surroundings.
• ZEB is not free of carbon emissions, glass has a high embodied energy, and the production requires a lot of carbon

8. 10 features of a 'green' building
1. Air tightness and vapour barrier in building
walls and surfaces
2. Low solar heat gain coefficient of glass
(SHGC)
3. Enthalpy recovery of exhaust air
4. Daylight-controlled lighting systems
5. Occupancy sensors
6. Water-efficient fittings
7. Rain-water harvesting
8. Materials recovery facility (MRF)
9. Vegetation
10. Site sustainability