Design Principles, Strategies, Technologies and Examples
Net-zero energy buildings represent a shift from simply making buildings “more sustainable” to designing buildings around a measurable energy-performance target.
A successful net-zero energy building does not achieve its goal merely by installing photovoltaic panels. The fundamental strategy is to reduce the building’s energy demand first, improve the efficiency of its envelope and building services, and then use renewable energy to balance the remaining annual energy requirement.
For architects, this means that energy performance must influence decisions about site planning, orientation, building form, façade design, glazing, shading, daylighting, ventilation, materials, HVAC systems, lighting, controls and renewable-energy integration from the earliest stages of design.
This article explains the concept of net-zero energy buildings, their principles, design process, major technologies, advantages, limitations, Indian context, and important international examples.
What Is a Net-Zero Energy Building?
A net-zero energy building is a highly energy-efficient building whose annual energy use is balanced by an equivalent amount of renewable energy generation according to the chosen accounting boundary.
The U.S. Department of Energy’s widely cited definition describes a zero-energy building as an energy-efficient building in which, on a source-energy basis, annual delivered energy is less than or equal to on-site renewable energy exported. Other programmes use different accounting boundaries, so the exact definition should always be stated when a project claims zero-energy performance.
In simple terms:
Reduce energy demand + improve energy efficiency + generate renewable energy = net-zero energy goal
The word “net” is important. A net-zero energy building can still import electricity from the grid at some times of the day or year. For example, a building may consume electricity at night when its photovoltaic system is not generating power and export electricity during sunny hours.
The annual balance is what matters under many net-zero-energy definitions.
Quick Answer: How Does a Net-Zero Energy Building Work?
A net-zero energy building works through four broad stages:
- Reduce energy demand through climate-responsive architecture and passive design.
- Improve system efficiency through efficient HVAC, lighting, equipment and controls.
- Generate renewable energy using technologies such as photovoltaic systems.
- Measure and verify performance to determine whether the annual energy balance has actually been achieved.
This approach is more effective than attempting to compensate for an inefficient building with a very large renewable-energy system.
Net-Zero Energy vs Net-Zero Carbon
These terms are related but they are not interchangeable.
| Concept | Primary concern | Typical focus |
|---|---|---|
| Net-zero energy | Energy balance | Energy consumed versus renewable energy generated |
| Net-zero operational carbon | Carbon emitted during operation | Energy efficiency and low-carbon energy |
| Net-zero whole-life carbon | Entire building life cycle | Operational + embodied carbon |
| Energy-positive building | Produces more energy than it uses | Surplus renewable energy |
A net-zero-energy building therefore should not automatically be described as a net-zero-carbon building.
World Green Building Council guidance increasingly emphasizes carbon because energy alone does not describe the complete environmental impact of a building. Operational emissions and embodied emissions need to be considered separately when evaluating broader net-zero-carbon objectives.
For architects, this distinction is important because a highly efficient building can still contain substantial embodied carbon from concrete, steel, aluminium, glazing and other materials.
Why Are Net-Zero Energy Buildings Important?
Buildings require energy for:
- Heating
- Cooling
- Ventilation
- Lighting
- Domestic hot water
- Appliances
- Office equipment
- Pumps
- Elevators
- Data and communication systems
- Other building services
Reducing these loads can decrease operating costs, energy demand and dependence on fossil-fuel-based electricity.
Net-zero-energy design can also support:
- Improved thermal comfort
- Better daylighting
- Improved indoor environmental quality
- Greater energy resilience
- Reduced operational emissions
- Lower exposure to energy-price fluctuations
- More efficient use of building systems
However, these benefits depend on good design and actual building operation. A building labelled “green” is not automatically a net-zero-energy building.
Principles of Net-Zero Energy Building Design
1. Start With Energy Demand Reduction
The first principle is simple:
Do not generate energy to compensate for energy that could have been avoided.
A building with excessive solar heat gain, poor insulation, uncontrolled air leakage and inefficient HVAC equipment may require a very large renewable-energy installation.
A better approach is to reduce the energy requirement through architectural decisions first.
The U.S. Department of Energy similarly emphasizes making a building as efficient as possible so that the renewable-energy system required to reach zero energy is smaller and more practical.
2. Understand the Site and Climate
Net-zero-energy design is fundamentally climate-responsive.
Before developing the building form, the architect should study:
- Solar path
- Solar radiation
- Prevailing wind
- Temperature
- Humidity
- Rainfall
- Seasonal variations
- Urban heat-island conditions
- Surrounding buildings
- Vegetation
- Site shading
- Ground conditions
- Local microclimate
The appropriate solution for a hot-dry climate will not necessarily be appropriate for a cold climate.
This is one reason net-zero architecture cannot be reduced to a universal checklist.
3. Optimize Building Orientation
Orientation affects:
- Solar heat gain
- Daylight availability
- Glare
- Natural ventilation
- Façade exposure
- PV potential
- Cooling demand
The optimum orientation depends on latitude, climate, building use, façade design and operational requirements.
Orientation should therefore be studied together with shading, window-to-wall ratio and building massing rather than treated as an isolated decision.
4. Optimize Building Form
Building form affects the relationship between:
- Floor area
- Envelope area
- Solar exposure
- Heat transfer
- Daylighting
- Natural ventilation
- Renewable-energy surface area
Compact forms can reduce the amount of exposed envelope per unit of floor area, while courtyards, atria and articulated forms may provide important daylight or ventilation benefits in particular climates.
There is no universally “best” net-zero building shape.
The correct form is the one that performs well for its climate, programme, orientation, occupancy pattern and site.
5. Design a High-Performance Building Envelope
The building envelope separates conditioned interior space from the exterior environment.
A high-performance envelope can include:
- Continuous insulation
- Reduced thermal bridging
- Controlled air leakage
- Appropriate glazing
- Solar-control glass
- External shading
- High-performance roof assemblies
- Appropriate wall construction
- Carefully designed junctions
Envelope design is particularly important because heating and cooling loads are strongly influenced by the relationship between indoor and outdoor conditions.
Thermal Bridges
Thermal bridges occur where heat flows more easily through part of the envelope because of geometry, material or construction details.
Common examples include:
- Structural connections
- Balcony slabs
- Window junctions
- Roof-wall interfaces
- Metal framing
- Penetrations
Reducing thermal bridges improves thermal performance and can also reduce condensation risk.
6. Control Solar Heat Gain
Solar radiation can be both a useful resource and a major source of unwanted heat.
Architectural responses include:
- Overhangs
- Horizontal fins
- Vertical fins
- Louvres
- Screens
- Recessed windows
- External shading
- Vegetation
- Appropriate glazing
- Dynamic shading systems
External shading is often particularly effective because it can intercept solar radiation before it reaches the interior glazing.
The shading geometry should be developed from actual solar-angle analysis rather than applied as decoration.
7. Use Daylighting Strategically
Daylighting can reduce dependence on artificial lighting, but excessive glazing is not automatically sustainable.
Large glazed façades may increase:
- Solar heat gain
- Cooling demand
- Glare
- Heat loss in some climates
- Façade cost
Effective daylighting therefore requires a balance between:
Daylight availability + solar control + glare control + thermal performance
Daylight strategies may include:
- Proper window placement
- Light shelves
- Reflective interior surfaces
- Clerestories
- Skylights where appropriate
- Shading
- Daylight-responsive controls
8. Use Natural Ventilation Where Climate Allows
Natural ventilation can reduce mechanical cooling and improve indoor air movement when outdoor conditions are suitable.
Strategies include:
- Cross ventilation
- Stack ventilation
- Operable windows
- Courtyards
- Ventilation shafts
- High-level openings
- Wind-driven ventilation
However, natural ventilation should not be treated as universally appropriate.
In climates with high outdoor temperature, humidity or pollution, mechanical ventilation and cooling may still be necessary.
9. Use Thermal Mass Carefully
Materials such as concrete, masonry and other high-thermal-mass assemblies can absorb and release heat over time.
Thermal mass can be useful when combined with appropriate:
- Solar exposure
- Night ventilation
- Insulation
- Temperature swings
- Occupancy schedules
Thermal mass is not inherently beneficial in every climate or building. Its effectiveness depends on how the building operates.
10. Improve HVAC Efficiency
HVAC systems can represent a substantial portion of building energy consumption.
Net-zero-oriented HVAC design should consider:
- Correct equipment sizing
- High-efficiency equipment
- Variable-speed systems
- Zoning
- Heat recovery
- Demand-controlled ventilation
- Efficient fans and pumps
- Appropriate refrigerant systems
- Smart controls
- Commissioning
- Preventive maintenance
The architectural design and HVAC design must be coordinated early.
A façade designed without considering HVAC loads can create expensive downstream problems.
11. Reduce Lighting Energy
Efficient lighting should combine:
- High-efficiency luminaires
- Daylight integration
- Occupancy sensors
- Dimming
- Task lighting
- Daylight-responsive controls
- Appropriate lighting levels
The objective is not simply to install efficient lamps but to reduce the amount of artificial lighting required in the first place.
12. Control Plug Loads
As buildings become more efficient, plug loads become increasingly important.
Plug loads can include:
- Computers
- Monitors
- Printers
- Kitchen appliances
- Servers
- Chargers
- Entertainment systems
- Office equipment
The U.S. Department of Energy identifies plug-load management as an important component of aggressive zero-energy performance.
Architects and building operators should therefore consider equipment selection and occupant-use patterns during energy modelling.
13. Integrate Renewable Energy
After reducing energy demand, the project can integrate renewable-energy systems.
Common technologies include:
- Solar photovoltaic panels
- Building-integrated photovoltaics
- Solar thermal systems
- Small-scale wind systems where appropriate
- Geothermal systems for heating/cooling applications
- Other renewable-energy systems appropriate to the site
For many buildings, photovoltaic generation is particularly important because roofs and façades can provide suitable surfaces for solar generation.
14. Design the Building’s “Energy Surface”
An important architectural issue is that renewable-energy systems require physical area.
PV systems require:
- Suitable orientation
- Solar exposure
- Structural support
- Access for maintenance
- Electrical infrastructure
- Protection from shading
- Space for equipment and routing
Therefore, renewable-energy generation should be considered during massing and roof design rather than added after the architectural design is complete.
The roof becomes not only a weather-protection element but potentially an energy-generating surface.
Types of Net-Zero Energy Buildings
Net-zero-energy principles can be applied to many building types.
| Building type | Important energy considerations | Typical design priorities |
|---|---|---|
| Residential | Cooling/heating, appliances, hot water | Envelope, shading, efficient equipment, PV |
| Office | HVAC, lighting, plug loads | Daylighting, façade, HVAC, controls |
| School | Lighting, ventilation, occupancy patterns | Daylight, orientation, natural ventilation, PV |
| Hospital | 24-hour operation, ventilation, equipment | Efficient HVAC, heat recovery, controls |
| Institutional | Variable occupancy and equipment | Zoning, envelope, energy monitoring |
| Retail | Lighting, cooling, refrigeration | Efficient lighting, HVAC and equipment |
| Industrial | Process energy | Process efficiency, waste heat recovery, renewables |
The energy strategy should always respond to the actual operational profile of the building.
A hospital operating 24 hours a day has a very different energy profile from a small residential building.
Key Architectural Elements of a Net-Zero Energy Building
A net-zero building can be understood as an integrated system rather than a collection of independent technologies.
Site
The site determines:
- Solar access
- Wind exposure
- Shading
- Vegetation
- Microclimate
- Renewable-energy potential
Building Form
Form influences:
- Surface-to-volume ratio
- Solar exposure
- Daylight
- Ventilation
- Energy demand
Envelope
The envelope controls:
- Heat transfer
- Air movement
- Solar gain
- Daylight
- Thermal comfort
Building Services
MEP systems determine much of the operational energy performance.
Renewable Energy
Renewable systems balance the remaining energy demand.
Controls
Building automation and controls help ensure that the designed performance is maintained during operation.
Net-Zero Energy Design Process
A useful architectural workflow is:
Step 1: Establish the performance target
Define:
- Building type
- Area
- Occupancy
- Operating hours
- Climate
- Energy boundary
- Performance metric
- Renewable-energy strategy
Step 2: Analyze the site
Study:
- Sun
- Wind
- Temperature
- Humidity
- Context
- Vegetation
- Shading
Step 3: Develop passive strategies
Test:
- Orientation
- Massing
- Shading
- Daylighting
- Natural ventilation
- Thermal mass
- Envelope strategy
Step 4: Create an energy model
Energy modelling can test design options before construction.
Variables may include:
- Building orientation
- Window-to-wall ratio
- Glazing
- Insulation
- Shading
- HVAC
- Lighting
- Occupancy
- Equipment
- Renewable-energy systems
Step 5: Optimize the envelope
The façade should be evaluated for thermal and solar performance rather than aesthetic appearance alone.
Step 6: Select efficient MEP systems
Coordinate HVAC, electrical, lighting, plumbing and controls with architectural decisions.
Step 7: Estimate renewable-energy generation
Determine how much renewable-energy generation is physically and technically possible.
Step 8: Iterate
The design process should move repeatedly between architecture, engineering and energy modelling.
Step 9: Commission the building
Equipment must be installed and operated according to design intent.
Step 10: Monitor actual performance
A net-zero claim should ultimately be supported by measured energy data where the applicable programme requires operational verification.
What Is Energy Use Intensity (EUI)?
Energy Use Intensity (EUI) expresses annual building energy consumption relative to floor area.
A simplified expression is:
EUI = Annual Energy Consumption ÷ Relevant Floor Area
It is commonly expressed in:
kWh/m²/year
EUI is useful because it allows energy performance to be compared relative to building size.
However, EUI should not be interpreted without considering:
- Building type
- Climate
- Occupancy
- Operating schedule
- Energy boundary
- Calculation method
A hospital and an office should not automatically be compared simply because both have an EUI value.
Site Energy and Source Energy
The term “net zero” can become confusing because different methodologies measure energy differently.
Site energy
Site energy refers broadly to energy delivered to and used at the building site.
Source energy
Source-energy approaches account for energy associated with supplying energy to the building, including upstream factors.
The choice of accounting method can influence whether a building qualifies as zero energy.
Therefore, an article, certification or project claim should identify the methodology being used instead of treating “zero energy” as a universal single calculation.
Net-Zero Energy Buildings in India
India provides an important context for net-zero-energy architecture because buildings operate across diverse climatic conditions.
The country’s commonly referenced climate categories include:
- Hot and dry
- Warm and humid
- Composite
- Temperate
- Cold
A successful net-zero strategy therefore needs climate-specific design.
India’s building-energy framework has also evolved considerably.
The Energy Conservation Building Code (ECBC) 2017 established energy-performance requirements for large commercial buildings and addresses areas including building envelope, HVAC, lighting, electrical systems and renewable energy. BEE states that ECBC 2017 applies to commercial buildings with connected load of 100 kW or greater or contract demand of 120 kVA or greater, subject to the applicable regulatory framework.
BEE has subsequently published the Energy Conservation and Sustainable Building Code 2024 (ECSBC 2024) for commercial and office buildings, representing a further development of India’s building-energy framework.
Architects should always check the code version and state/local adoption applicable to a specific project rather than assuming that a national model code automatically applies identically everywhere.
BEE Shunya Labelling Programme
India’s Bureau of Energy Efficiency introduced the Shunya Labelling Programme for Net Zero Energy Buildings and Net Positive Energy Buildings.
BEE’s published material identifies:
- Shunya: EPI from 10 to 0 kWh/m²/year
- Shunya+: EPI below 0 kWh/m²/year
The programme is intended to encourage buildings to improve energy efficiency and progress toward net-zero or net-positive energy performance.
This is particularly relevant for Indian architects because it provides a national context for discussing zero-energy performance rather than relying exclusively on international terminology.
Important Indian Example: Indira Paryavaran Bhawan
Project: Indira Paryavaran Bhawan
Location: New Delhi, India
Use: Government office
Completed/inaugurated: 2014
Significance: Presented by the Government of India as India’s first on-site net-zero building.
The project was designed around solar-passive strategies, energy-efficient materials and renewable-energy generation.
Its significance lies not only in the photovoltaic installation but in the combination of:
- Solar-responsive planning
- Daylighting
- Shading
- Energy-efficient systems
- Landscape strategies
- Renewable-energy generation
It is an important Indian case study because it demonstrates that net-zero-energy objectives can be integrated into a large institutional building rather than being limited to small houses.
International Example: Bullitt Center
Project: Bullitt Center
Location: Seattle, Washington, USA
Building type: Commercial office
Architectural significance: High-performance commercial building designed around aggressive environmental goals.
The U.S. Department of Energy identifies the Bullitt Center as a zero-energy office whose rooftop photovoltaic system generates approximately as much energy annually as the building uses.
The project combines energy performance with other environmental strategies, including water management and material considerations.
The architectural lesson is important:
Net-zero performance is strongest when energy strategies are integrated into a broader building-performance concept rather than added as isolated technologies.
International Example: NREL Research Support Facility
Project: Research Support Facility
Location: Golden, Colorado, USA
Client/Institution: National Renewable Energy Laboratory
Completed: 2010
Building type: Office/research facility
The Research Support Facility is an important example of combining architectural design with building-performance engineering.
Its strategies include:
- Daylighting
- Natural ventilation
- Efficient systems
- High-performance envelope strategies
- Photovoltaic generation
- Building monitoring
The project demonstrates the importance of considering energy performance during architectural planning rather than treating energy as an engineering problem added later.
International Example: Powerhouse Brattørkaia
Project: Powerhouse Brattørkaia
Location: Trondheim, Norway
Architect: Snøhetta
Completed: 2019
Building type: Office
Powerhouse Brattørkaia goes beyond conventional net-zero-energy thinking and is described by its project team as an energy-positive building.
Its architecture is strongly shaped by solar-energy generation. The roof and upper façade incorporate almost 3,000 m² of solar panels, while the building also uses highly insulated construction, heat recovery, efficient systems and optimized daylighting.
The project demonstrates an important principle:
Energy performance can become a generator of architectural form rather than a constraint applied after form-making.
Net-Zero Energy Building Design Strategies by Building Element
| Building element | Energy strategy | Architectural implication |
|---|---|---|
| Site | Solar and wind analysis | Site planning becomes performance-driven |
| Orientation | Optimize solar exposure | Building axis affects energy demand |
| Massing | Reduce unwanted heat transfer | Form becomes part of energy strategy |
| Façade | Insulation, glazing, shading | Envelope is a thermal-control system |
| Roof | Insulation + PV | Roof becomes an energy-generating surface |
| Windows | Daylight + solar control | Glazing requires climate-specific optimization |
| Interior | Daylight + zoning | Space planning affects energy use |
| HVAC | High efficiency + controls | MEP coordination begins early |
| Lighting | Daylight + efficient luminaires | Lighting load can be reduced |
| Landscape | Shade + microclimate | Landscape contributes to environmental performance |
| Controls | Monitoring + automation | Building operation becomes measurable |
| Renewable energy | PV and other systems | Energy generation becomes part of architectural planning |
Advantages of Net-Zero Energy Buildings
Reduced Energy Consumption
Energy-efficient design reduces the building’s demand before renewable energy is considered.
Lower Operating Energy Costs
Reduced energy consumption and renewable generation can reduce dependence on purchased energy.
Actual financial performance depends on capital cost, energy prices, financing, maintenance, tariffs and building operation.
Better Thermal Comfort
High-performance envelopes and properly designed systems can create more stable interior conditions.
Reduced Dependence on Fossil-Fuel Energy
Renewable-energy integration can reduce dependence on conventional energy sources.
Greater Energy Resilience
Distributed generation and, where appropriate, energy storage can improve resilience during some grid disruptions, although resilience depends on system configuration and whether critical loads can remain powered.
Improved Design Integration
A well-designed net-zero project encourages closer coordination between architecture, structure, landscape and MEP disciplines.
Challenges of Net-Zero Energy Buildings
1. Higher Initial Investment
High-performance envelopes, renewable systems, controls and commissioning can increase initial costs.
However, project economics should be evaluated through life-cycle analysis rather than first cost alone.
2. Limited Renewable-Energy Area
Dense urban buildings may not have enough roof or façade area to generate all required energy on site.
This is particularly challenging for:
- Tall buildings
- High-density developments
- Buildings with large energy loads
- Buildings with extensive shading
- Sites with limited solar access
3. Complex Coordination
Net-zero performance requires collaboration among:
- Architect
- Structural engineer
- MEP engineer
- Energy modeller
- Landscape architect
- Contractor
- Commissioning team
- Owner
- Facility manager
4. Occupant Behaviour
Actual energy consumption can differ from design assumptions because of occupant behaviour, schedules, equipment use and operational changes.
5. Performance Gap
A building can perform differently from the original simulation because of:
- Construction quality
- Equipment settings
- Incomplete commissioning
- Occupancy changes
- Control problems
- Maintenance issues
- Weather variation
6. Renewable-Energy Maintenance
PV systems, inverters, batteries and other renewable-energy systems require inspection and maintenance.
7. Embodied Carbon
Reducing operational energy does not automatically eliminate the environmental impact associated with construction materials.
This is why net-zero-energy design should increasingly be coordinated with whole-life carbon thinking.
Common Mistakes in Net-Zero Energy Building Design
Mistake 1: Adding Solar Panels at the End
Solar should be considered during early massing and roof planning.
Mistake 2: Treating Glazing as Automatically Sustainable
More daylight can be beneficial, but excessive glazing can increase cooling loads and glare.
Mistake 3: Ignoring Climate
A strategy suitable for a cold climate may perform poorly in a hot-humid climate.
Mistake 4: Designing Architecture and HVAC Separately
Building form, envelope and mechanical systems interact continuously.
Mistake 5: Ignoring Plug Loads
Computers, appliances and equipment can become significant loads in efficient buildings.
Mistake 6: Using Generic Energy Targets
Performance targets should reflect building type, climate, occupancy and applicable methodology.
Mistake 7: Relying Entirely on Simulation
Simulation is essential, but actual performance must be monitored after occupancy.
Mistake 8: Confusing Net-Zero Energy With Net-Zero Carbon
Energy and carbon are related but different performance metrics.
Practical Checklist for Architects
Before finalizing a net-zero-energy building concept, ask:
Site
- Have solar and wind conditions been analyzed?
- Is the building orientation appropriate?
- Has surrounding shading been studied?
Form
- Is the massing appropriate for the climate?
- Has surface-to-volume performance been considered?
- Is renewable-energy area available?
Envelope
- Is insulation adequate?
- Are thermal bridges controlled?
- Is glazing appropriate?
- Is external shading optimized?
Interior
- Is daylight distributed effectively?
- Are high-load spaces strategically located?
- Can circulation and planning reduce unnecessary conditioning?
MEP
- Is HVAC properly sized?
- Are efficient systems specified?
- Are controls integrated?
- Are heat recovery opportunities considered?
Renewable Energy
- Is there enough area for PV?
- Has shading been considered?
- Is the structural design coordinated with the renewable system?
- Is access for maintenance provided?
Performance
- Has an energy model been developed?
- Has the design been tested iteratively?
- Are energy targets clearly documented?
- Will the building be commissioned and monitored?
The Future of Net-Zero Energy Architecture
The future of net-zero-energy architecture is moving beyond the simple combination of “efficient building + solar panels.”
Emerging directions include:
- Building-integrated photovoltaics
- Battery energy storage
- Smart building controls
- Grid-interactive buildings
- Advanced energy modelling
- Parametric design optimization
- Digital twins
- Demand response
- Electrification
- Heat pumps
- Advanced façades
- Adaptive shading
- Low-carbon materials
- Whole-life carbon assessment
- Building-to-grid interaction
Recent research also increasingly explores how advanced modelling, responsive envelopes, automation and renewable-energy integration can be coordinated across different climates.
The important architectural lesson is that technology should support good environmental design rather than replace it.
Net-Zero Energy Buildings: Key Takeaway
A net-zero energy building is not simply a building covered with solar panels.
It is a building designed around an integrated performance strategy:
Climate analysis → Site planning → Building form → Passive design → High-performance envelope → Efficient MEP → Controls → Renewable energy → Monitoring
The architect’s role is therefore broader than selecting sustainable materials or adding renewable technologies. Architects influence the fundamental energy demand of the building through orientation, massing, spatial planning, façade design, daylighting, shading, ventilation and coordination with building services.
The strongest net-zero projects demonstrate that energy performance can improve architecture rather than compromise it.
Conclusion
Net-zero energy buildings represent an important evolution in sustainable architecture because they establish a measurable relationship between energy demand and renewable-energy generation.
The most reliable pathway is to reduce demand first through climate-responsive architecture, passive strategies and high-performance envelopes. Efficient HVAC, lighting, equipment and controls then reduce the remaining operational load. Renewable-energy systems can subsequently balance the annual energy requirement.
For architecture students, net-zero energy design provides an opportunity to understand how environmental performance influences form, orientation, envelope and planning.
For practicing architects, it requires an integrated workflow in which architecture and building services are developed together from the beginning.
Most importantly, a net-zero-energy target should be treated as a performance objective that must be calculated, designed, tested and eventually verified, rather than as a visual style or collection of green technologies.
References
The principal sources used for the technical and factual framework of this article include the U.S. Department of Energy, NREL, Bureau of Energy Efficiency, BIS, IEA, AIA, World Green Building Council and documented project sources.