Category: energy efficiency

26
Jun
2017

Zero energy homes | the Passivhaus approach to reducing energy bills in homes

The focus of this discussion is achieving a zero energy home through the Passivhaus approach.

True or false – adding insulation has diminishing returns? True, doubling the thickness of a roof insulation doubles the cost while halving the heat loss/gain, and half of a half is a quarter and half of that an eighth…. So, “How low should we go?” as some have asked. The idea behind the Passivhaus program, developed in Germany, is to break through the cost barrier by sealing and insulating the bejesus out of an envelope till the need for mechanical equipment is eliminated (apart from fresh-air delivery).   What about the applicability of the system to the mid-Atlantic region? According to Galen Staengl, Passivhaus-certified energy consultant, “It’s still an open question as to where the cost/performance balance is struck in in our region where cooling and dehumidification are also required.” Even with the adaptability of the approach to different climates still being explored, the program offers valuable insight into how we might crack the zero energy code.

The Passivhaus program is performance-based. To achieve the 4.7 kBtu/ft/yr goal, recommended R-values for walls are R-40, for roofs, R-60. At the Hickory Hall project at the College of Emory & Henry in Virginia consulting engineer Staengl says this is achieved with a wall system comprised of 2×6 studs with cellulose insulation and 2 1/2″ of EPS insulation outside of the sheathing – all building techniques well understood by contractors and resulting in a cost increase of only 5%. The Contracting firm of Structures Design Build, located in Roanoke, Virginia alters the DNA of the typical wall section by adding a modified Larsen truss outside of the studs and sheathing. The truss, truss joists turned on their side with the webbing removed, is filled with cellulose.

The Passivhaus approach doesn’t stop at the envelope. In the US, where the climate varies from hot to cold and somewhere in between, and where some parts see enough humidity to wilt Blanche Dubois’ curls, energy-efficient lighting and equipment, especially hot water heating, need to be addressed.   And of course, all the other aspects we’ve discussed above are thrown into the stone soup of the Passivhaus approach resulting in a HERS rating of between 20-30.

One of the challenges of the application of Passivhaus approach in the US is availability of cost-friendly materials. Triple-pane windows, a must for the approach, are just beginning to show up in the marketplace. Happily many of the major window manufacturers are getting on-board and Marvin, Pella and Milgard all offer triple pane options. In Europe where energy codes now mandate a Passivhaus approach, triple pane windows have become the norm — and costs are lower than for double pane — the more stringent codes in Europe are affecting a radical change in the marketplace.

In addition to the significant energy savings of the Passivhaus approach, consider the indoor climate. A recently completed home in Virginia Beach uses triple pane windows and the temperature of the glass is ten degrees warmer in the winter. The increased

Triple Pane Windows

Triple pane windows in this home reduce energy bills and increase comfort. The temperature at the windows is 10 degrees warmer in the winter.

comfort associated with a well-designed envelope is palpable and a nice side benefit to reduced energy bills.

13
Oct
2016

In pursuit of happiness – the question of size and architecture

In November of 2014 I wrote about the Not so Big Apartment and of Gary Chang’s clever Swiss army knife style apartment that transforms into 24 different spaces.   I admired the inventiveness of Cheng’s project and the notion of living well in a small setting.

The topic of size comes up a lot at architectural conferences. The issue is an important one for obvious reasons – bigger homes require more energy to heat and cool and more energy goes into the construction materials. Clients however aren’t always so interested in the notion of doing with less. That’s not surprising in the US, home to the super-sized Big Mac and it’s cousin the McMansion.

At HEDS we think big, from the perspective of living well, is beside the point –size has very little to do with the qualities that foster a sense of well-being and happiness. Size is what builders promote in the absence of good design. This is size over substance thinking – size is a false prize.

We share our clients’ goal that our designs should contribute to their happiness and well-being. In pursuit of their happiness, we promote more substantive qualities such as homes that bring richness through CLEVER ideas. Other qualities we pursue in our designs: FUN, COMMUNITY at all levels (between siblings, within the family, with neighbors and the larger community), a connection with NATURE, and last but not least, COOL.

In pursuit of COOL: The Exbury Egg by Pad Studio, Spud Group and Stephen Turner.

In pursuit of COOL: The Exbury Egg by Pad Studio, Spud Group and Stephen Turner.

Children's room

In pursuit of FUN and COMMUNITY. This kids room has a shared loft. An art wall exhibits the children’s masks. A window between the children’s rooms fosters community between siblings. When small these children held hands between the window and have grown up to be close friends. Woolen Mills House by HEDS.

Dogtrot House

In Pursuit of Nature: A captured outdoor space brings nature into the daily living for this home’s occupants. The space is used for sitting and dining during the spring, summer and fall. Dogtrot House by HEDS. Photo by Prakash Patel.

29
Aug
2016

affordable green buildings: lessons from the Make It Right Homes

To understand how to build affordable green buildings, it’s useful to look toward low-income communities where these strategies are being applied at scale, where costs and paybacks are being measured. The Make It Right (MIR) Foundation is just such a test-bed community – a Petri dish for our examination. Make It Right builds affordable green homes and buildings and began by with the reconstruction of the Lower 9th Ward in New Orleans after Hurricane Katrina. Started by Brad Pitt in 2007, Make it Right buildings are LEED Platinum certified and inspired by Cradle to Cradle thinking. The MIR Foundation’s primary goal is to change the building industry by implementing green building strategies that is affordable to all.   MIR utilizes an array of methods:

  •  Advanced framing to reduce material and labor costs: studs at 24″ on center or the use of structural insulated panels are some of the techniques used (R-25 walls, R-33 roof, R-13 subfloor).  Less labor means more affordable.  Less materials means more green.
  • Interior finishes that are low or no off-gassing make for healthy living.
  • Green electrical through wireless electrical system (Verve).  The higher cost of the system is offset by lower cost for installation.
  • A high velocity air-conditioning system reduces size of duct/trunk lines which can then run in the structure, saving on structural and finishing costs.
  • Well insulated walls and air tight buildings reduce energy loads and therfore long-term operational costs.  Green Insulation such as spray foam and recycled denim insulation are used.
  • Low-flow faucets, shower heads and dual flush toilets reduce water consumption.
  • Cisterns for irrigation also reduce water usage.
  • Tankless water heaters means no tanks — water is heated only when needed which reduces energy costs.
  • 4.25 KW solar array (grid-tied/net-metered) uses the sun to generate energy for the buildings.
  • Building Information Management (BIM) allows the organization to analyze and reconfigure the building DNA as it evolves.  BIM provides feedback to increase the efficiencies to make their buildings ever more affordable and green.

The typical HERS (Home Energy Rating System) of a home is 100. The typical Make it Right home has a HERS rating of 15-20, or an 80% reduction in energy use over the typical. For $150/SF, including solar panels (of which a portion receives a government tax goodies), this is a remarkable feat.

02
Aug
2016

Modern Green Virginia Beach House Tour

Tour of soon-to-be-finished modern green Virginia beach house on August 11th at 6:00 PM.  Meet at the Cavalier Golf and Yacht Club (parking lot nearest the clubhouse) at 1052 Cardinal Road, Virginia Beach, VA.  Attendance limited.  Please RSVP to aewing@hays-ewing.com.

House features:

Superinsulated and designed to meet Passivhaus standards, triple glazed windows, Huber Zip system, FSC certified woods and many other sustainable features.  A second floor outdoor covered living space offers a stunning view of Linkhorn Bay.  See also Facebook event.

Virginia beach architects

Custom home located in Virginia Beach.

12
Apr
2016

Virginia Beach House Tour

Announcing a house tour at the soon-to-be completed house on Linkhorn Bay in Virginia Beach.  The tour will be postponed date to be determined.  We will meet in the parking lot of the Cavalier Golf and Yacht Club at 1052 Cardinal Road, Virginia Beach.  Limited attendance.  Please RSVP to aewing@hays-ewing.com See more details below.

tour_brochure.pptx

26
Oct
2015

Lewis & Clark Exploratory Center of Virginia: Engaging people is key to a building’s success

We design with the philosophy that engaging people in our buildings is key to a project’s success.  We think a lot about how to create opportunities for discovery, for collaboration, for a conversation with nature… Take for example, The Lewis & Clark Exploratory Center (LCEC).  We designed the roof as an vegetated garden/overlook to the Rivanna River.  This is where a visitor first arrives and the roof signals the building’s larger goals: to connect to the Lewis & Clark story, and to engage the visitor with nature.  The vegetated roof is to be planted with species gathered by the explorers on their journey west.  The overlook, with a replica of a ship in the foreground and the Rivanna in the background, recalls to the visitor that the exploration was carried out by river.  The building also teaches about water, how precious it is, how it is the source of life: the roof water is directed to a riverstone channel that flanks the stairs descending to the exhibit space.  Water is collected in a basin at the entry below and the visitor crosses a bridge to enter the building – again, references to Lewis & Clark’s river journey as well as modern concerns about the environment and the importance of water quality.  The building is designed to achieve LEED Silver, and its many sustainable features are teaching examples for visitors.  Best of all though is how active the center is with community activities.  The building teaches about the Lewis & Clark’s journey, about nature while serving as an ideal setting for the activities organized by LCEC.  It is gratifying to see our goals realized.  IMG_1463IMG_1478

16
Sep
2015

Sustainable design requires creative solutions

A sustainable architect needs to solve for more than would the typical designer.  I liken our process to solving the Rubic’s cube – where all the goals, challenges and givens must be in alignment.  The typical architect might be solving for the nine squares/side cube, we are solving for the 16 square/side Rubic.  Take for instance HEDS-designed RiversEdge House: Good urban design suggested house be sited in alignment with street grid.  Classic #PassiveSolar approach would rotate the primary windows toward south and shade with deep overhangs.  But the street grid wasn’t on a north-south axis.  To solve for both passive solar and urban siting, we angled the front wall toward south while maintaining the overall orientation to that of the street.

This project was designed as part of the RiversEdge community and speculative – we were the developers.  We know first-hand that passive solar takes advantage of free energy from the sun at no additional cost to the builder – a win-win solution.  RiversEdge5-heds

31
Aug
2015

Harness the Sun at the Community Level

huangbaiyuhouse_blog

Design for passive solar home in China proposes wind turbine and vegetable gardens on roofs.

Passive solar design is well understood yet little considered at the community design level. New York City planners had the foresight to lay out the NYC street grid with solar aspect in mind. For community planners, considering solar path is so simple yet largely ignored.  Imagine laying out streets and houses around the sun so that rooms enjoy daylight without solar heat gain, where front and rear yards are oriented on the north-south axis and sideyards to east and west. Thus floor plans can more easily be adapted to locate the service spaces to the north (kitchen, closets, baths) and living spaces (living, dining, bedrooms) to the south.  This simple idea can have a profound effect on the long-term energy use of the individual homes and of the neighborhood collectively and with little or no cost, has big marketing potential. Community developers and planners should wake up to the logic of this win-win solution.

village_blog

The design of this new community in China (team led by Allison Ewing while Partner at William McDonough + Partners) was designed to take advantage of solar path at all scales of design, from the community to the room.

 

16
May
2014

safety in numbers

In Aristotelian terms, techné, craftmanship, craft or art, was considered the imperfect practice of nature.  Nature was regarded as teacher and keeper.   In the three millennia that have elapsed since the Greeks first pondered the making of things, techné has been replaced by technology which sees nature as something to harness, nature is conceived in subjective (human) terms.  We have much to learn from nature, from the birds and the bees, as we consider how to retool our thinking.  Take for instance the penguin that survives extreme cold by huddling, thereby creating a microclimate.  Living in a community, apart from the social benefits, creates a microclimate where the free exchange of heat and cold is sanctioned; in winter the upstairs neighbor benefits, in summer the gift is exchanged (through radiation and surface transfer). Happily, this is a strategy the Developer-Builder can embrace because party walls equals less expensive perimeter equals lower costs.   Safety in numbers.