EchoHaven House

EchoHaven House

Vital Stats

Certification Status Zero Energy Certified
Date of Certification January 10, 2018
Version of LBC 3.1
Location Calgary, AB
Typology Building
Project Area 2,750 SF
Start of Occupancy June 2012
Owner Occupied Yes
Occupancy Type Single Family Residence
Number of Occupants 2

Project Team

Owner Dave Spencer + Debbie Wiltshire
Project Manager Kim Walton
General Contractor Sunergy Systems Ltd.
Architect Kim Walton, Bow Crow Design
MEP Engineer Bill Crist, mechanical engineer; Gordon Howell, electrical engineer
Lighting Design Dave Spencer
Interior Design Debbie Wiltshire
Specialty Consultants Dave Spencer, overall planning + landscape architecture
Photo Courtesy of Bow Crow Design Photo Courtesy of Bow Crow Design

Building Systems Information

Wall R value and section specification R59. Larson truss with interior chord load bearing. Flashed at the exterior with 3 ½” of 2lb polyurethane and 8” dense pack cellulose fibre at the interior. Exterior finish Acrylic stucco over a cement and metal base. Interior finish drywall.
Roof R value and section specification R108.
Floor R value and section specification R70.
Windows High-performance fiberglass windows have less frame and more glass capitalizing on the insulation value of the glass. All windows incorporate low iron glass. South windows have a higher SHGC and therefore a higher U value. The windows in all other orientations have a lower U value and lower SHGC.
Air infiltration rate and sealing protocol 1.04 (ACH-50). Balloon framing and exterior insulation outside of the floor system prevent leakage at the floor system. Windows and doors sealed with peel and stick membrane. Spray foam used around windows and susceptible areas. Dense pack cellulose fills gaps and seals up the rest including up to and over the high heels of the trusses.

Non-Mechanical Systems

The well-insulated, sealed envelope and high-performance windows contribute to the comfort of the home. Minimizing heat loss throughout the building envelope reduces the need for heat. The use of large south facing windows with a high SHGC contributes to both lighting and passive heating. The thicker drywall (5/8”) and concrete floors help to absorb and retain heat gain. The heat is released in the evening as the temperature cools inside.

Mechanical Heating and Cooling

The home is heated with radiant electric panels by Thermoray which are installed behind the drywall on ceilings. Thicker than normal drywall was used throughout the house to add to the mass exposed to sunlight and the heat from the radiant electric panels.

Mechanical Ventilation

A Heat Recovery Ventilator (HRV) was required for the airtight house. During the planning phase of the project, the intent was to efficiently operate the HRV with less energy.

There were many discussions about how it would be possible to use CO2 sensors to control the HRV automatically. The HRV typically runs at timed intervals, and using CO2 sensors would activate the HRV only when needed. In the end, the complication, cost and additional energy loads required for this type of system made it untenable. The HRV is a Lifebreath model 195 ECM (electronically commutated motor). The unit is ducted to supply air to bedrooms and living areas. Exhaust is from the bathrooms, kitchen and laundry room.

Modifications to the normal HRV system have been made through the installation of 150 cfm in-line booster fans for the exhaust of the bathrooms and the kitchen. The booster fans are wired to timers in these rooms.

Hot Water

The house has a modest area of solar thermal collectors integrated into the siding. The orientation is vertical and facing east of south. In the vertical orientation, the best gain will be realized in the winter months. The solar thermal panels are dedicated to heating water for domestic use. The system is a closed loop system. Occasionally, the water in the storage tank will be heated to a temperature that is higher than what is needed for everyday needs. When this happens, excess heat will be directed through a simple loop embedded in the concrete slab of the lower level living area. This provides the opportunity to extend the effectiveness of the collectors.

The collection area for the solar domestic hot water panels is 56 SF. The insulated storage tank is a 300-litre Eco-King with 15 SF of exchange area. Preheated water from the storage tank is directed to the electric on-demand heater for domestic hot water use. A grey water heat recovery unit, Renewability Power-Pipe, is used to moderate the temperature of the incoming fresh water for the water heating system. Water from the bathroom fixtures drains through the heat recovery unit warming incoming fresh water that is traveling to the SDHW tank.

Lighting

Layered lighting used in living spaces. Liberal use of interior windows and translucent materials to allow light to be used from one area to another without turning on lights. A few task lights are cold cathode fluorescents, all others are LED.

User Load Reduction Strategies

The lighting fixtures for the house are a combination of low energy usage LED and fluorescent. Interior glazing is used throughout the house to reduce the need to turn lights on during daytime hours or when adjacent rooms are lit.

Energy efficient appliances from local suppliers are used throughout the house. The EnerGuide rating of the appliances is as follows: refrigerator – 539 kwh/yr, dishwasher –180kwh/yr, oven – 253 kwh/yr, washer –125 kwh/yr, dryer – 400 kwh/yr.

An induction cooktop and convection oven have been incorporated so that cooking energy is used more efficiently. The clothes dryer is a condensation dryer that does not require venting to the outdoors and the water collected can be used to water plants. The laundry room is fitted with clothes drying racks for air drying. Refrigeration needs are reduced with the incorporation of a “cool pantry” which is an insulated closet in the kitchen. Cool air is provided through a pipe which has been buried for ~ 60’ in the backfill around the residence. It surfaces on the north side of the house to a screened riser. The pantry is exhausted through a PVC pipe exiting below the roof sheathing and extending out of the soffit. A fan located on the supply pipe is operated with a thermostat in the pantry.

The kitchen exhaust does not vent to the outdoors. A booster fan has been added to the HRV system to increase the exhaust capacity to the HRV.

A “kill switch” has been incorporated as part of a strategy to reduce ghost loads. Duplexes that will service non-essential appliances and lighting are turned off when the “kill switch” is activated. The switch is located beside the garage door so that the house can be “shut down” upon leaving for the day. Exterior lighting is minimal and located near the exterior doors only.

Photo Courtesy of Bow Crow Design Photo Courtesy of Bow Crow Design

Performance

Actual energy use during performance period 5,965 kWh
Actual energy produced during performance period 6,164 kWh
Net Energy Use -199 kWh
EUI 3.41 kBTU/sf/yr

Project Leadership and Story of Project

The EchoHaven NZ house is one of 25 high-performance homes planned for in the EchoHaven development. Five founding families, who all aspired to build high-performance homes, purchased the land with the vision of developing a sustainable, low-impact community. Guiding principles included water conservation and management strategies, universal solar access, integration of natural features, zero greenhouse gas emissions, and minimal ecological footprints. The owners are founding members of the community and the first to build. During the preliminary design stage, they entered the home in the CMHC EQuilibrium competition and were selected along with twelve other entrants to build a demonstration home. The agreement with CMHC entailed a comprehensive process of reporting and reviews starting with a two-day integrated design charette, and culminating with the owners hosting tours for hundreds of visitors prior to occupancy.

Photo Courtesy of Bow Crow Design Photo Courtesy of Bow Crow Design

Design Process

The owners organized a 2-day integrated design charrette and engaged a professional facilitator for the event. Themes followed the general CMHC EQuilibrium sustainable performance themes and indicators:

  • Occupant health and comfort
  • Energy conservation, efficiency, and production
  • Resource conservation; materials, durability, embodied energy, resource and water conservation, flex-housing and accessibility
  • Reduced Environmental Impact, biophysical impacts, stormwater impact mitigation
  • Affordability; costs, benefits, and marketing

Approximately 30 experts and the owners participated in the event along with a municipal government official. Areas of expertise included:

  • Building envelope
  • Indoor air quality
  • Sustainable materials
  • Architectural and Interior design
  • Native plants
  • Financial
  • Builders/contractors
  • Electrical, mechanical engineering
  • Modeling and certification
  • Stormwater
  • Costing
  • Renewables
The charette was guided by these broad themes. Individuals presented ideas associated with their expertise and the group explored the ideas and how they could be integrated into the design. The larger group regularly split up into smaller working groups to challenge the preconceived assumptions and dialogue about innovative solutions. Working groups presented their key findings back to the entire group to test validity and discuss how they could be incorporated. Many concepts resulted in modifications to the house and whole house systems, including several innovations that were unique among all the demonstration homes.
Photo Courtesy of Bow Crow Design Photo Courtesy of Bow Crow Design

Occupancy Issues

Due to a separate building permit, the inspector was unfamiliar with and had to be educated to determine if the solar thermal hot water heating system met the building code.

Building Commissioning, Start Up, and Optimization

The net-zero elements had an impact on the building costs. Accredited assessors have strict rules regarding what they can value in their assessment – additional insulation, energy efficiency systems, and renewables were not included. The bank assessment does not recognize the lower level as living space even though it is mostly fully finished to the same standard as the upper level. This caused some problems with financing while building. The bank appraisal is much lower than the appraisal done by the insurance company. In addition, limiting mortgage rules are a deterrent to people who don’t have high equity to finance ratios.

The topic of affordability was a consistent theme that was discussed during the design charette. In order to gain acceptability in the market, every cost during construction had to be evaluated with the question, “will this result in a reasonable payback period and not be so technologically complex that it scares buyers and hinder adoption?”

The project received a government grant (CMHC) during the design and monitoring phases of the project. However, the amount of work required far exceeded the money received. In addition, the project received a provincial rebate for achieving an EnerGuide rating of over 85.

Regulatory Issues

The project team faced two major challenges with the city plumbing inspector: 1) the thermal storage tank did not have a CSA certification sticker which was a requirement. As it turns out, thermal storage tanks have no standards for certification. An engineer’s report was required to resolve this issue. 2) rainwater collection and re-use were promoted by the City, however, there were no guidelines in place. As part of the development approval, the developer created guidelines based on other jurisdictions and the CSA guidelines and these were written into the zoning bylaw. However, the inspector arbitrarily stated his own rules, such as additional safety measures and disallowing rainwater for clothes washing. These decisions resulted in negative impacts, such as: increased costs and setbacks to the adoption of rainwater collection/reuse in the City in general. Years later, the provincial and municipal jurisdictions have not resolved rainwater use in general except to make it practically impossible to use. The owners intend to continue lobbying for changes.

Energy Related Building Component Suggestions

During the time of construction, choosing to use solar thermal proved to be expensive, however, PV systems were also expensive during the time of construction. With the cost of PV today, the owners will likely add more PV for electric DHW or an air to air heat pump rather than the more complex solar thermal system.

The owners pioneered the use of LED lighting throughout the house to reduce electrical loads. At the time, the wiring and install of remote drivers were expensive. Currently, LED fixtures generally have integral drivers, thus allowing them to be cheaper and more effective.

Lessons Learned

The south-facing living spaces provide lots of light and ambiance. High insulation values make the house comfortable and quiet. There is nothing that the owners dislike about the house but they might do some things differently if they were to build again, like: they would have opted out of using a solar thermal system for domestic hot water which was an expensive install, and they would consider using cost-effective electric baseboard space heating rather than electric radiant panels.

  • Inline fans in mechanical air system were an innovation to deal with bathroom moisture and kitchen exhaust and avoid envelope penetrations. The fans are activated individually by timers. Exhausts go through the HRV rather than vented directly outside. There was some concern about kitchen exhaust particulates accumulating in the HRV filters however this has not been the case.
  • Condensing clothes dryer – also to eliminate an envelope penetration for exhaust. Has worked better than expected. Captured condensate is clean and used for watering plants
  • Home comfort. This is subjective and difficult to convey unless you live in a house like this for an extended period. The owners are very happy about air quality, thermal comfort, summer ventilation, outside sound abatement, and the interaction they have between the house and whatever is happening outdoors. In short, they have become very emotionally attached to their home and could not go back to a typical code-built house.