Each month I will be covering a specific topic on ‘Green Home Design Practices’. Check back here every couple weeks for updated information and advice.
Topic One: What are the cost savings of a green house vs a regular house?
There are many variables which effect the percentage of savings of a ‘Green’ home vs. a ‘Regular’ home. It all boils down to four main factors: proper design and integration of systems; construction techniques; region; and goals.
There are several factors which need to be considered when assessing savings. These are:
- Material and labor costs for initial installation;
- Life Cycle costs for up keep and operation;
- Return on investment.
In a properly designed system, the goal is to minimize the amount of time for your return on investment (ROI). Factors such as government grants, incentives and buy back programs will reduce this time period.
60% reduction in energy costs
Example: Achieve a 60% savings on energy costs on a basic residential renovation project.
Project: Renovation and expansion of an existing 1959 ranch home in a moderately cold climate.
Envelope: 45% reduction of heat gain/loss. Construct high performance envelope exceeding local energy codes by 20% and incorporate rainscreen exterior facade design to minimize thermal bridging. Incorporate natural daylighting and proper shading to reduce electric light usage and thermal heat gain.
HVAC: Change from gas and electric to geothermal HVAC system results in 66% savings on energy bills. Incorporate geo-thermal heating and cooling and design (2) solar passive cooling towners operated by a program logic controller for ease of operation.
Electric: Design photo-voltaic panel system to off set cost of operation of geothermal system.
After the ROI has been met in 5-7 years, the operation of the HVAC system will be completely offset by the production of electricity.
From $1800 to $600 annually
Energy speaking only… the home outlined above used $1,800.00 annually for gas and electric. After the ROI period the anticipated energy cost wll be approximately $600., or a savings of roughly 66% annually.
Keep in mind, this does not take into account the cost of renovations and the high performance envelope. For new construction expect to pay 10% more in construction costs to achieve a high performance envelope.
In closing, implementation of only one part of the equation will not result in meeting your goals for energy savings. You must take all parts into consideration so in order to meet your goals.