What is Building Envelope?
The building envelope is the interface between the interior of the building and the outdoor environment, including the walls, roof, and foundation (Center for Climate & Energy Solutions, C2ES). A building’s envelope can be optimized to reduce the amount of cooling and heating it requires to keep its tenants comfortable and to reduce the utility costs for building owners.
For instance, building envelope insulation can reduce the amount of energy flow, thereby reducing the heating and cooling loads on energy systems. Similarly, roof designs and insulation can reduce the amount of air-conditioning required during cooling months because hot air rises to the top (ENERGY STAR® rated roofs can reduce peak cooling loads by 10 to 15%).
Wall insulation and material selection for the façade also affect the amount of energy needed to heat and cool the building. Thermal mass buildings can absorb energy slowly and hold it longer in the interior, effectively reducing the fluctuating energy demands placed on the HVAC systems.
Windows, exterior doors and skylights (“fenestration”) can also help to reduce the lighting needs as well as heating and cooling loads. For instance, multiple glazing of windows or filling the spaces between panes with low-conductivity gas are effective means of reducing the flow of energy from the building.
Costs & Savings
For a typical home, an ENERGY STAR® window will save $126 to $465 per year when replacing single-pane windows and $27 to $111 per year when replacing double-pane windows (C2ES). New buildings can be built to accommodate low energy needs through better building envelope insulation, roof and façade designs, window placements and weatherization.
Additionally, financial incentives in the form of rebates, tax credits, low-interest loans, third party financing and innovative financing are available to offset the upfront costs of installing these efficiency measures.
Associated Renewable helps buildings become more energy efficient through simple but cost-effective changes to building envelopes and also helps owners finance these measures. Please contact the energy Solutions team at (212)-444-8215 to request a free proposal.