Deep Energy Retrofits and Zero Energy Homes

Buildings account for 40% of all energy used in this country. Energy use in existing homes accounts for 21% of all energy used. Houses built before 1973 were not built to the standards of today. They were built at a time when energy was cheap and global warming was not a concern. Most of these homes will still be occupied in 2050. There are now approximately 60 million housing units were built before 1973.

There is now a tremendous opportunity to take these older homes and give them energy “facelift”. The term “Deep Energy retrofits” has been applied to projects that bring these houses up to a high performance standard. The ultimate goal is to create homes that are “carbon neutral” or “net-zero-energy”, in which the house is able to produce as much or more energy than what it consumes.

This is done through a combination of improvements to the “thermal envelope”, a sharp reduction of the energy loads, changes in occupant behavior and the addition of renewable energy technologies.

Some of the techniques that are used in a deep energy retrofit are:

• Replacement of existing insulation and/or the addition new high quality insulation.
• Replacement of existing windows with high performance windows
• Careful air sealing of all joints between materials
• Replacement of old appliances with Energy Star appliances
• Replacement of incandescent light bulbs with compact fluorescents or LED’s
• Upgrading of heating and cooling system to high efficiency (sized correctly based on the new insulation values)
• Installation of heat recovery ventilation system (to bring in fresh air efficiently)
• Installation of solar photovoltaic and solar hot water systems
• Creation of “passive solar” features (sunroom, south facing glass exposures).

Process and Services:

Rountree Architects (RA) is a full service architectural firm that specializes in residential design. RA has been in business 18 years and has become a leader in energy efficient design and the use of passive and active solar technologies. Most of our work involves renovations and additions to existing houses.

After a brief phone conversation, an initial meeting is usually scheduled to meet and discuss the client’s intentions and the architect’s services. After the scope of the project is determined, Rountree Architects will prepare and deliver a written proposal outlining our services and fees.

Our process generally involves three phases:

Phase 1 – Energy Audit:

A full house “energy audit” is done initially. A complete house inspection will determine the existing conditions of the house from an energy standpoint. This may involve using a “blower door test” to determine the “air-tightness” of the house and the areas of greatest weakness.  It might also involve the use infrared photography to further determine where heat loss is occurring. The mechanical systems of the house will be examined and analyzed to determine the age and efficiency level of the equipment. All energy using appliances will be documented and their age and condition noted.

One year of all utility bills will be taken and used as a baseline to measure future improvements.

Physical measurements will be taken and used to develop floor plans that can be used to determine the size of the house and for heat loss calculations. They will also be used to generate Construct Documents for any new work to be performed on the house (Phase 2).

A final report will be prepared that will make recommendations on measures that can be taken to improve the energy performance of the house. Although a detailed cost estimate will not be given, a range of probable costs would be provided along with each recommended improvement.

Phase 2 – Construction Documents:

If the client chooses to implement any or all of the proposed improvements, a detailed construction drawing will be prepared including written specifications describing the improvements. Together, these will constitute the “Construction Documents (CD)”. The CD’s will be used: 1) to serve as a bid package and issued to qualified contractors, 2) to serve as the basis for a contractual agreement between the owner and the contractor, 3) to obtain any and all construction permits and 4) to build from.

RA will then assist the owner in locating and selecting the best-qualified contractor to do the work. RA will prepare AIA contracts between the owner and the contractor if that is desired.

Phase 3 - Construction

During construction, RA will act as the owner’s representative and will make periodic site visits to meet with the owner and the contractor and review the work to assure that it is in compliance with the CD’s. RA will also review and approve all invoices from the contractor before payments are made.

Fees:

Fees for professional services will be determined on a project-by-project basis. In general, full fees will be in the range of 9% - 11% of the construction cost.

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