Blog

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.

28
Jul
2016

Solar Energy: Let the sun shape the roof

Solar energy is becoming more affordable by the day (see blog post 3/16/2106).  Before long, the cost for solar power will become cheaper than grid-sourced.  Twenty years ago the payback on solar was roughly equal to the lifespan of the solar array.  Still, we designed our roofs to accept solar panels, looking forward to the day that the economic case could be made to mount those panels on a project’s roof.  Recently-built Solar Faber project has not had to wait for those panels – with a return on investment of over 5%, the economic case can now be made.  The big, south facing roof of the project was designed with that intent.  What’s more, if the sun shapes the roof, the roof shapes the interior of the house, adding height and interest.  It’s a two-for-one proposition that makes so much sense for both the environment and the quality of life for the building owner.

Solar energy: roof design

If the sun shapes the roof, the roof shapes the interior.

11
May
2016

Virginia’s Lewis & Clark Exploratory Center in film

Teen filmmaker James Hill documentary showcases the Lewis & Clark Exploratory Center’s green features.  It’s great to see the next generation taking on these serious questions.

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

09
Mar
2016

Solar Power becoming dirt cheap

A new product will make solar energy dirt cheap.  Solar power used to have a payback of about 20 years. The lifespan of photovoltaic (PV) panels was about 20 years, making solar a difficult sell given the high cost. We knew one day the price of PVs would become cheaper than fossil fuels and that day is not far off. While oil prices are coming down, so are PVs –the price of solar and other green technologies are offering affordable options to renewable power.  In fact, some projections see the cost of solar becoming cheaper than fossil fuels within five years.  Researchers developing the new solar cell made with perovskites (current technology uses silicon), project the technology will cost just 10 to 20 cents per watt. Currently, solar costs around 75 cents a watt.  The  U.S. Department of Energy projects 50 cents per watt will allow solar power to compete with oil.

A new start-up Oxford Photovoltaics is commercializing the product.  Meanwhile, solar cells made with silicon are also coming down in price.  All this is great news for achieving net zero at an affordable cost. Solar power, green architects virginia

01
Feb
2016

Creating layers of value – What’s good for environment is good for business.

We consider a project unsatisfactory if it’s just beautiful.  We consider a project unsatisfactory if it’s only green — or only functional.  We consider a project falls short if it’s not a good fit for it’s natural setting or urban context.  We seek to create layers of value.  Case in point:  We were asked by Norfolk region based Haynes Furniture to do a facelift on their exterior facade.  Our solution – create a facade that is beautiful but also shades the entrance glazing from unwanted heat gain.  Beautiful and functional.  We wanted to transform the parking lot to one that was full of trees and native plants that filter stormwater before it reaches the endangered Chesapeake Bay.  Beautiful, native to place and green.

We believe by adding layers of value our clients get more for their investment.  Good for the environment, good for business.green architect Norfolk

 

28
Dec
2015

Low-energy solutions

We humans, occupants of the habitat we call The World, find ourselves in a predicament – confronted by a changing environment, we must adapt and do so quickly, achieving carbon neutrality by 2030 (See Ed Mazria’s 2030 Challenge). Advocates of biomimicry point to nature, with 3.8 billion years of R&D, as a source for cost-effective, low-energy strategies.  I recently read about the “Ripe Chair,” a project by Andreas Konradsen, part of the DON’T RUN OUT exhibit held in Paris this week, where a steel frame chair was submerged in salt water to naturally weld the joints.  ripe_chair

This process recalls one the Romans used in the production of concrete – they compacted volcanic ash and lime in forms submerged in sea water.  The mix, when in contact with sea water, underwent a chemical reaction to form concrete more durable than today’s.

Those of us architects focussed on sustainability think a lot about creating zero-energy use buildings.  The energy that goes into the production of materials used in buildings is equally important with the embodied energy associated with materials attributed to many years of a building’s life cycle costs.

Among the many materials buildings employ, concrete is the biggest contributor to greenhouse gases (an estimated at 7%).  The Roman’s knew how to produce low-energy concrete, how is it we continue to produce high-energy Portland Cement when there are solutions?  Research into alternatives, such as Belite Cement, is underway and Drexel University has produced a low-energy concrete.  There are other researchers exploring low-energy solutions.  Once these alternatives are on the market, I’m hoping the building industry can move quickly embrace the DON’T RUN OUT philosophy to integrate these technologies into new construction.