**7. Conclusions**

This chapter reviewed various techniques and designs that help achieve a netzero energy building. The most important techniques are optimizing HVAC designs to reduce energy consumptions and usage of renewable sources. Some of the techniques include geothermal heat pumps, underfloor air distribution, radiant floor heating and cooling, retractable external blind on windows, and proper orientation of the building which would maximize heat gains in cold weather and minimize it in summer using trackable blinds, photoelectric daylight sensor, and occupancy sensor. Renewable sources include fuel and biomass cells, biogas, photovoltaic cells, and EPA wood stove for heating. Water usage as well could be optimized by using gray water reclamation and by using rainwater-to-potable live water systems.

Net-zero energy building design starts with ethical clients and demonstrators. Designers and users need to be lean in their designs to reduce the energy consumption, be clean by using energy-efficient utilities and systems, and be green by using renewable energy sources such as biomass, wind, solar, geothermal heat sink, and rivers. Canals could be a good source for heat pumps in cold weather regions [22].

Future buildings will focus more on renewable and sustainable energy resources by implementing an efficient building envelope and utilizing energy-efficient and

high-performing utilities promoting reduced energy consumption levels. Future design will benefit from various potential energy resources including solar, wind, tidal, biomass, and other resources. Future system design and selection will need to simulate the various cases, variables, and scenarios to decide on optimized building design such as exposure, orientation, window to wall ratio, shading, building envelope, etc. In addition to that, artificial intelligence (AI) will play a major role in the operation and maintenance of such buildings including smart meters, smart display boards that recommend actions to tenants to reduce energy consumption, lighting control versus shading, and air-conditioning operation. Governments, local states, and cities have to commit to get this into track. They should facilitate sources access and should force using the guidelines and codes.
