Project Summary | Low Energy Home

This primary residence incorporates the comfort of radiant floors and air conditioning, together with constant fresh air supplied by a heat recovery ventilator, electricity from a grid-tied photovoltaic system, and domestic hot water from a flat plate solar hot water system.

ZED performed a detailed cost-benefit analysis on variety of possible conventionally framed wall and roof assemblies for the building envelope, including advanced framed versions, rigid exterior foam, open cell sprayfoam, and closed cell sprayfoam paired together with cellulose or blown fiberglass. After reviewing the relative incremental costs, operational energy savings, and carbon dioxide emission reductions, the decision was made to utilize 2x4 framing at 16" on center for the walls with dense-packed cellulose within the cavity plus 2 inches of continuous polyiso rigid insulation for an R value of 26, paired with the roof assembly of R-47 and R-4 windows. Renewable energy systems include both solar hot water and 5.5kW of solar electric. The Energy Star certified home achieved the challenging Massachusetts Tier III and a HERS 24.

ZED provided energy modeling, cost analysis, building science consulting, and mechanical design for the residence.

Project Summary | Fossil Fuel Free Consumption

ZED performed a detailed cost-benefit analysis on variety of wall construction systems, including insulated concrete forms (ICFs), structural insulated panels (SIPs), and conventional framing. Taking into account the relative incremental costs and operational energy savings of each wall system, the design team made the decision to utilize conventional 2x6 wood framing for the walls with a continuous layer of exterior XPS rigid insulation, combined with 3 inches of closed cell spray foam and 2.5 inches of blown-in fiberglass in the wall cavity. The combination provides a true R-value of 33, superior for the Maryland climate. Continuous rigid insulation mitigates thermal bridging through the wall assembly while the combination of continuous rigid insulation and closed cell spray foam provide redundant air barriers to minimize unwanted air infiltration. When paired with the roof assembly of R-51 and R-6 windows, the homeowners will benefit from an exceptional building envelope.

This fossil fuel free house incorporates a ground source heat pump with a horizontal loop to provide heating and cooling. An energy recovery ventilator maintains excellent indoor air quality by providing a constant supply of fresh air at a minimal energy expense. Hot water is mostly provided by a solar hot water system and a photovoltaic system will offset much of the total remaining energy consumption. ZED provided energy modeling, cost analysis, building science consulting, and mechanical design for the residence. Residence visualization and architecture by 2e Architects.

Project Summary | Low Energy Home

The Truro Residence has a magnificent, west-facing view over the water. The architectural design of the house captures this view through expansive west-facing windows. Unfortunately, this violates a basic principle of passive solar design - limit west-facing glazing to mitigate unwanted afternoon heat gain. Performance feedback from an energy model identified design features to compensate for the extra heat gain and meet the client's aggressive energy goals. Features like 10" staggered stud walls filled with spray foam, large overhangs, low solar gain glass coatings, and a high efficiency HVAC system result in the home using two-thirds less energy than a code-built equivalent home.

The efficient HVAC system contributes to the home's low energy footprint. The ground source heat pump provides highly efficient year-round heating and cooling. The radiant floors are well suited for the home's high ceilings since they avoid hot air stratification. A heat recovery ventilator maintains healthy indoor air quality by providing fresh air ventilation but minimizes energy losses by exchanging heat between incoming and outgoing air streams. A majority of the remaining electricity use is offset by photovoltaic panels on the southern roof.

Located in the Boston suburbs, this couple chose to build their new home with 80% better heating performance than minimum code requirements, saving both energy and reducing their annual carbon emissions.

The super-insulated structure includes an R-55 roof assembly, R-45 walls using an EIFS system (synthetic stucco over EPS foam insulation with liquid-applied weather barrier), and European style R5 tilt and turn windows. The natural gas boiler with radiant floor heating is complemented by a dedicated heat recovery ventilator (HRV) supplying a constant stream of fresh air.

ZED provided architecture, energy modeling, cost analysis, building science consulting, and HVAC design for the residence.

This 1912 Craftsman residence needed a general update, as evidenced by the ancient tube and knob wiring still in use, single pane windows, 1960's-era boiler, asbestos insulation, and numerous other issues.

ZED designed system updates for the building envelope, electrical, and mechanical systems. Thermal photography and blower door tests were used to track before/after comparisons. Thermal envelope improvements include adding foam insulation in existing walls, insulating the foundation, replacing existing windows with Energy Star windows, installing a heat recovery ventilator, and replacing the entire heating and cooling system.

The owner of this duplex home is completing a deep energy retrofit on one dwelling unit and an EnerPHit renovation on the other.

For older buildings it is often difficult to achieve the Passive House standard with reasonable effort. The use of Passive House technology for each building component in such buildings, however, does lead to considerable improvement in respect of comfort, structural protection, cost-effectiveness and energy requirements.

For quality assurance and verification of the specific energy values achieved, buildings that have been modernized using Passive House components and that does exceed the Passive House boundary values can receive the "EnerPHit – Quality-Approved Modernization with Passive House Components" certificate.

Target attributes of the EnerPHit unit in this project are a R66 roof assembly and R54 walls with <1.0ACH@50 for air infiltration.

With spectacular panoramic views of the ocean at higher levels, this home maximizes height and incorporates a smaller building footprint for the square footage. The homeowners felt that energy performance was an important goal, asking ZED to reduce the home’s energy consumption and design the HVAC system.

The lakefront site for this home in Maine has a view facing due north and is shaded by a mature tree canopy. The combination precludes passive solar gain and the use of renewable energy, however provides a clear opportunity to target a high performance building envelope and efficient mechanical systems.

Advanced framing with spray foam combined with an exterior layer of continuous rigid insulation improves the R-value of the wall assembly, reduces thermal bridging, and greatly decreases air infiltration.

A high efficiency propane boiler supplies heatthe remote home site. A high efficiency tankless hot water heater provides domestic hot water. A heat recovery ventilator efficiently provides a source of continuous fresh air.

ZED provided architecture, energy modeling, building science consulting, and HVAC design for the residence.

Targeted energy performance is 55% better than International Energy Conservation Code requirements.

The Needham Residence homeowner asked ZED to improve the energy performance of their new home through energy modeling and HVAC consulting.

The homeowner's priorities included cost effective means of saving energy, with a minimum reduction of 50% better than code requirements.  ZED designed a wall assembly with spray foam insulation in the walls and roof to increase energy conservation, matched with a WaterFurnace closed loop geothermal system for highly efficient consumption.  A heat recovery ventilator was incorporated to efficiently maintain excellent indoor air quality.