Reduce your environmental footprint one strategy at a time.

Ellen speaking about Energy Efficient Design on Monday, September 21st.

Posted on | September 17, 2009 | No Comments

NYSECCC DOB PRESENTATIONOn Monday, September 21st at 3:30 Ellen is giving a talk with Matt Bendix, PE entitled ”Energy Code Design for Residential Buildings”.  The event will be hosted by HOK Architects at 620 Avenue of the Americas #6, NYC.

This session is part of the NYC Department of Buildings – Hosted Seminars in Energy Conserving Design and the Energy Code in conjunction with the Urban Green Expo being held next week.

This session is geared towards licensed professionals and will include energy-conserving strategies for residential buildings such as reducing air infiltration, tightening the building envelope, reducing lighting and cooling loads and providing efficient heating, ventilating and cooling systems.

Click here for more information.

Great fan timer and no liquid soap!

Posted on | August 25, 2009 | 2 Comments

Bathroom fan timer switchOn each House Call I learn something new!

On one site visit this week I saw a fantastic bathroom timer switch. You can set it to have the fan stay on for 1 to 60 minutes (The Home Ventilation Institute recommends keeping an exhaust fan on 20 minutes after using a shower to remove moisture from the room).

I saw this post about the timers at Re-Nest.  You can get other great controls by clicking here.

nosoapThe other fun fact I learned was not to use liquid soap.

Makes sense right?

It is engineered to stay liquid in the bottle so why wouldn’t it stay congealed in your pipes.  Foam soap is better because the particles are smaller and less cohesive.  My client’s plumber said liquid soap was the best thing that ever happened to his business.

And never use anti-bacterial soap.  It’s bad for the waterways and your health!

Kids Today

Posted on | August 20, 2009 | No Comments

This is a follow up post about the Green Team program at the Urban Assembly Institute of Math and Science for Young Women,

IMG_0288It was incredible working with these 11 spirited girls.  Their presentation showing what they learned about ecology and green building  was lively and informative.

Look what they did in just 5 weeks (and this is only 8 hours per week).

The courtyard will be used as an outdoor classroom with the homemade planters at the perimeter and the benches used for seating.  The triangular shapes will be used as part of the geometry curriculum and the vegetables will be tended and harvested by the students in the fall.

Here are some of the girls’ experiences, in their own words:

Surquonna SoleynMaya SpiersQuaisan P.Rema BryceEmoni, Kayonda Marshall.


This is one of the planters in construction

This is one of the benches

This is one of the benches

Broccoli and lettuce grown from seeds

Broccoli and lettuce grown from seeds

Painted courtyard

Painted courtyard

Looking forward to next year!

Off the grid & off the pipe…in San Francisco

Posted on | August 9, 2009 | No Comments

netzerosanfranThis is a post from Green Architecture Notes published by Feldman Architecture out in San Francisco.  It describes an energy-neutral house proposed to be constructed next year.

With all the building trends moving towards sustainability here in New York City, it is still SO MUCH more difficult to do a net-zero house here than in the Bay Area.

For one thing, our buildings are generally taller with smaller footprints so the proportion of available roof area (for renewable energy) to living area is much smaller.  Also, our winters are colder and our summers hotter and more humid so we use much more energy for heating and cooling.  Not to make excuses but a net-zero house here is kind of like the holy grail.

Given that we’re comparing climates, I thought I’d take this opportunity to introduce the concept of degree days which are a useful tool to compare climates or assess energy efficiency strategies.

There are many ways to calculate degree days.  The simplest formula is to subtract 65 degrees from the average daily temperature.  If the number is greater than zero, it is equivalent to that number of cooling degree days (CDD), if the number is less than zero, it is equivalent to that number of heating degree days (HDD).

For example.  Today’s high was 82 and low was 76.  The average temperature is 79 degrees.  79 degrees minus 65 degrees = 14 cooling degree days.  You can conveniently add them up to get monthly and seasonal totals and compare different climates or different time periods within the same climate.  

For comparison purposes, I downloaded the last 12 month’s heating degree days and cooling degree days for San Franciso and New York City from

As you can see, New York City has much higher number of heating and cooling degree days which means that a building in New York City would need to use more energy for heat and cooling to maintain the same comfort level as would a comparable building in the Bay Area.



You can also use this information to assess recent energy efficiency improvements.

You would adjust the post-improvement annual energy consumption with the pre-improvement consumption by degree days in order to compare “apples to apples”.

For example, if you are thinking that the extra insulation you added last fall didn’t work as well as you thought, it could be that we just had a colder winter so your bills were higher than you might have expected, even with the added insulation.  The chart below shows that the 08/09 winter (in green) was, in fact, colder than the 07/08 winter (shown in blue).


Brooklyn Bio-Diversity

Posted on | August 2, 2009 | No Comments


brooklyn_monarch_butterflyWe just heard about the Windsor Terrace Greenway Project.
The group’s mission is to encourage residents in the Windsor Terrace area to plant butterfly and bird friendly plants to support travel for birds and butterflies between Prospect Park and Greenwood Cemetery (see map below).
We live just outside the greenway but we’ll be planting something butterfly friendly in our window boxes.  Kudos to the organizers of this project for starting it.

Find out more at the

Have a stoop sale

Posted on | July 31, 2009 | No Comments

A stoop sale gives you a Quadruple Whammy:


    1. You get rid of junk.
    2. You can find a new home for the things you no longer have a use for.
    3. You can schmooze with the neighbors (bonus points if you augment your stoop sale with a bake sale).
    4. Make a few bucks!

 You can increase your audience by teaming up with neighbors or even make it a block party event.  Here are 6 tips to a successful stoop sale from NY Magazine.  

If you’d prefer to shop than host (and you live in Brooklyn), check out before you head out shopping for treasures on the weekend.  

If flea markets are more your thing, check out Brooklyn Flea in Fort Greene on Saturdays and under the Brooklyn Bridge on Sundays.

Greening the school during summer recess

Posted on | July 31, 2009 | No Comments

img_0564School’s out for the summer but for 11 girls at the Urban Assembly Institute of Math and Science for Young Women, it’s time to get their Green on!

This spring Ellen worked with 2 of the UA’s excellent teachers Noam Pillischer, a math teacher and Kelly O’Conner, an English teacher, Mara Lewin-Tankel, the UA’s Development Director and Micah Kotch of the Polytechnic Institute of NYU to develop a green curriculum for the UA’s summer program, called The Green Team.

The curriculum includes lessons about ecology, energy conservation, food and other environmental issues.  A central feature of the program is to have the girls get some hands-on experience and build something.  The idea is to have a rarely used courtyard become a kind of outdoor classroom with the girls building planters and benches to be used by all the students when they return to school in the fall.

During one of the first sessions, the students watched An Inconvenient Truth. “Kind of bland” was the review by one of the students but things got better as the program progressed.  Later trips to the green cafe Habana Outpost was a lot of fun and a visit to the Climate Change exhibit at the Museum of Natural History was interesting and inspiring.

Guests came to speak to the girls such as Zack from Green Guerillas, who spoke about helping people establish and maintain community gardens.  Yours Truly (Ellen) spoke about green building and what were the ideas behind the design of the courtyard project.  Mihail Kossev from Edible Landscape came to speak about how different vegetables grow in urban environments.

Now to the fun part.


Picture of the courtyard "before"


Drawing of the plan for the green courtyard

The area at the far left will be an outdoor classroom.  Eventually we want to plant green roof modules to make the areas feel a little cooler and quieter.

The triangles painted on the pavement are based on various mathematical concepts (full disclosure – Noam had to remind me about the triangle formulas – but it came right back I swear).  All the triangles on the right side are 3-4-5 triangles in different sizes.  No matter how you measure them, the proportion stays the same.  The girls did a FANTASTIC JOB of measuring and painting the triangles as you can see.

Measure twice...cut once

Measure twice...cut once

Making a triangle template on a rainy day

Making a triangle template on a rainy day

Painting the triangles

Painting the triangles



The center area is meant to house the long planter beds.  We gave the girls  step-by-step drawings of the planters and benches and they used math to figure out the amount of wood they would need.

Calculating the sizes of the wood pieces

Calculating the sizes of the wood pieces

Measuring the wood

Measuring the wood

This is the bench they are building:




And here’s the planter:






Stay tuned for pictures of the finished courtyard.

Free water conservation kit from NYC DEP

Posted on | July 27, 2009 | 1 Comment

3734322184_846d8e1455_mYou can get your own free water conservation kit from NYC DEP.

We ordered one which I expect to arrive in 2 weeks.

In the meantime, order yours here and read this great post from Green Home NYC to show you what you can expect.

Happy Conserving!

If you only have 20 or 30 minutes…

Posted on | July 13, 2009 | No Comments


If you have a half hour to spare, you should watch this presentation by Saul Griffith, founder of WattzOn from Pop!Tech 2008 – it is the clearest and most comprehensive discussion of power usage in the modern lifestyle. Saul talks about where energy comes from, how it’s made and how we waste incredible amounts of it on a daily basis. The numbers are shocking but it puts into perspective how our choices truly impact the global environment. If you watch with your school-age kid, the gigantic and colorful graphics will give you many learning and teaching opportunities. I can guarantee that it will change the way you eat, work and travel.


and if you have only 20 minutes, watch The Story of Stuff with Annie Leonard.  It’s a lightly (and adorably) animated depiction of how resources are turned into consumer products.  The focus is on using less stuff but it also clearly describes the environmental and health effects relating to overconsumption – perfect for kids who have a 20 minute attention span.

Any community that considers itself sustainable must consider its food source in order to remain truly environmentally and economically sustainable.

For now, let’s consider the following books – these 3 really made a difference to my way of thinking:


Fast Food Nation by Eric Schlosser analyzes how the American Fast Food diet came to be. He reveals how corporations have hijacked the American food supply. The first chapter starts out scary and each successive chapter gets more and more unbelievable…but true.


Omnivore’s Dilemma is one of the best books I have ever read…about any subject. Michael Pollan is an investigative journalist who turned his attentions to the American food chain. The length of the food chain in each of 4 chapters gets successively shorter until he describes how he hunted and foraged his own dinner. He covers topics such as organic chemistry, conventional farming, a wonderful chapter about a “grass farm” and leaves the reader with a deep respect for how food arrives on the table.


Barbara Kingsolver’s Animal, Vegetable, Miracle is a journal of a year in her family’s life when they decided to grow their own food and eat only locally obtained ingredients in SW Virginia. She describes the arc of vegetable farming from seeds to harvest with love and appreciation and (almost) makes you want to chuck it all and move back to the land.

and lastly, on the big screen:

Radiant Floors

Posted on | June 19, 2009 | 2 Comments


Radiant Heating diagram courtesy of This Old House

Radiant flooring (also called warm floors or underfloor heating) is a method of providing heat via a series of tubes that carry hot water and are installed just below the surface of the floor.   The Romans used this technology in their baths 2000 years ago by heating fires below their stone floors.

The main benefit of radiant flooring is how comfortable and consistent the heat is.

Heat rises…so the heat in the floor is delivered directly to where the occupants are.  Unlike with a forced air system, there is less energy wasted warming up the ambient air in order to keep the occupants comfortable and no filters to change or allergens blowing around.  And unlike with a steam heating system, there are no knocking noises or potential for burns from steam radiators. Reply from Genarro:  You say in your post that heat rises. It doesn’t. Hot air is lighter than cold air but that is a function of air displacement and gravity.  Actual heat moves any which way from hot to cold. The reason radiant heating is so great is that the heat radiates, which is one of the ways heat can move through space. (With apologies to my Science Teachers – I forgot about the first law of thermodynamics!)

At the top of this post is a diagram from This Old House showing how a typical radiant heating system works.   A boiler sends hot water (not steam) through a series of tubes fastened below the finished flooring.  The warmth from the hot water in the tubes radiates upwards and is transferred directly to the space above.  

As with all sustainable strategies, this one is not appropriate for every building.  We have had successful results installing radiant heating below solid wood flooring, engineered wood flooring and bamboo floors.  However, if you can install radiant flooring below or embedded in a tile or concrete floor  you will have a even better result because the mass of the masonry holds the heat and releases it slowly.

I toured a green brownstone under construction at 22 2nd Street in Carroll Gardens, Brooklyn, being built by Gennaro Brooks-Church of Eco Brooklyn.  It has many interesting green features but it was the radiant heating that caught my eye due to some innovative adjustments which I’ll describe below.


Picture #1: Warmboard subflooring

Picture #1 shows installation of the tubing in a Warmboard subfloor.  Warmboard is a combination structural subfloor and radiant heating system.  Genarro basically made his own Warmboard subfloor with plywood but wrapped the plywood cutouts in sheet aluminum to help radiate the heat upwards and filled in all the gaps between the tubing and the plywood with concrete to add thermal mass as well as reduce the amount of air in the floor (air is a terrible conductor of heat)


Picture #2: Homemade Warmboard with aluminum and concrete.

Other innovations at EcoBrooklyn: encasing the underside of the entire structural bay in concrete to add thermal mass to the design (Picture #3).  Genarro said that was very time intensive so he tried to focus the encasement of just the tubing in concrete for added insulation and thermal mass (Picture #4).


Picture #3: Encasing the structural bay in concrete


Picture #4: Encasing tubing in concrete

Picture #5 shows the manifold connection to and from the boiler in the Cellar.


Picture #5: Manifold to/from boiler

We’ll check in with Genarro later in the project to see how this system is holding up.

« go backkeep looking »


Established in 1999, Ellen Honigstock Architect PC is a full-service architecture and energy auditing firm based in DUMBO, Brooklyn.

Our solutions are environmentally conscious and the criteria we use are based on national standards developed to bring long-term saving, efficiency and well-being to our clients. Over 35 years combined experience building in New York City gives us an edge in meeting tough schedules and navigating the city's complicated requirements.

About Ellen:

As the Residential Green Building Advocate for the Urban Green Council since 2007, Ellen has been promoting sustainability in the residential marketplace in NYC.

In the position of Chair of the Homes Subcommittee the NYC Greening the Codes Task Force, Ellen has been heavily involved in recommending new green policy in NYC as related to updating building codes, rules and regulations.

Ellen teaches Building Science, Building Envelope, Water Conservation, Indoor Air Quality, Quantifying Energy and Green Building Plans at the 1,000 Green Supers program for The SEIU Local 32 BJ Thomas Shortman Training Fund.

Registered Architect, NY, NJ, CT
LEED Accredited Professional
BPI Certifications:
Building Analyst
Energy Efficient Building Operator
Multi-Family Building Analyst

Ellen Honigstock, LEED AP
Ellen Honigstock Architect PC
45 Main Street #806
Brooklyn, NY 11201
(212) 228-1585


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