The Friday Five – November 6th, 2015


It’s been a rough week and I’ve been slacking on my reading. Here are 5 articles not necessarily from this week, but saved from past weeks that I thought were interesting.

Reassessing Passive Solar Design Principles

by Martin Holladay via Green Building Advisor

A rare free article from Martin Holladay was published a few weeks back that challenged a few basic principles in sustainable design bibles. If you love to geek out on Green Building, then Martin’s posts, and everything over at Green Building Advisor is well worth the annual subscription fee.

Martin tackles core tactics that many of us have been using since the 70’s, including ourselves to some degree in our first projects. Practices like solar orientation, south facing glazing and thermal massing.  The bottom line is that these once critical practices in low energy construction are now mostly made defunct by better building materials and practices in today’s super insulated and Passive Houses. Today’s uber efficinet homes have more insulation and better insulation, are much more airtight and have higher quality windows. Martin proves that these things trump the old passive solar design principles we all grew up learning.

Passive Solar Design

Lloyd Alter over at Treehugger also found this post intriguing and did his own write-up called Everything I ever knew or said about green sustainable design was probably wrong. This is where I first heard of Martin’s article and it shocked me a bit to be honest.

I took a look back at some of the principles we’ve tried and some we’ve moved on from.

Thermal Mass: Our first couple of projects featured exposed slab on grade concrete floors. Partly for budget, but also to increase thermal mass to collect solar gain from the windows and mitigate temperature fluctuations. We’ve moved on from this and it hasn’t hurt our energy ratings or seemingly effected the comfort of the homes negatively without them.

Solar Orientation: We used to stress out a lot about this in our first projects. Trying to max out solar facing glazing as much as possible. In the end, we set this aside for the most part because we just don’t have much control over orientation at all on Philly’s tight infill lots. Also, if you have fantastic orientation in the rear of a house, you can’t just eliminate or drastically reduce windows on the front facade due to orientation. You’d leave the house looking silly from the street and reduce way too much light, air and views from that side of the building inside.

Window Type: When we first started, we spent the time figuring out which windows should have high or low heat gain glazing spec’ed. Then we did some research that promoted all high solar heat gain spec’ed on all windows to gather as much heat as possible in heating dominant climates. Recently, a window order was messed up and they sent us all low solar gain windows. We called Magrann to run the energy calcs and they told us in a few hours that it actually had a very slight improvement to our overall energy model for the homes. Now we’re back to all low SHGC windows which is a lot easier to order in the US.

We also switched to triple pane windows early on and have stuck with them until our latest project under construction. Long story short, the largest supplier of glazing in the US is no longer making triple panes in reasonable sizes. This forced us into double pane windows for the first time in over 5 years. Again, we called up Magrann to compare the energy difference in our model. They came back with a whole extra $10 a year increase in utility bills and less than 1% impact to our energy model. This kind of made me angry. Are we wasting this money and effort? The jury is still out as Passive House pushes for triple pane for occupant comfort as much as they do energy efficiency. We’ll get back to you on our final verdict…

Old vs new buildings

Researchers Develop Smart Window Coating that Controls Light and Heat Transmission Independently

via arch daily

Since we’re on the topic of windows and energy and blowing away assumptions we’ve carried for years, we thought this article was interesting. This new glazing technology could change this whole discussion again. We need to keep Martin’s plate full of topics to write on for us anyways.

Smart Window Coating

Pedestrianizing Alleys Means Taming Trash

by Jon Geeting via Plan Philly

This article caught my eye for a few reasons. First, we love the recent push for open streets and transforming underused alleyways in our fine city. Keep it up folks. Second, we’re working with our K’House crew to help transform Hope St in South Kenzo in a similar fashion. More on that another time. And lastly, this test street on Moravian is the same trash strewn and dumpster infested block we bought our very first house in Philly on. We loved that dirty little street and would be amazed to see it transformed. The house that was sold to buy the shell we flipped in Fishtown that funded the start of this little company.

Pedestrian Streets

Multifamily Retrofit – E_RC / MAPA.a

via arch daily

Love this retrofit. The brick details are amazing. The units are tiny, but open and filled with light. A fantastic example of an urban retrofit in the city.


 Temporary Retrofit: Micro-Dwellings for Unoccupied Buildings

via web Urbanist

Speaking of retrofits, why fix something up when you can just setup some Micro-Dwellings in them? Cool concept and we could see people doing this in Philly.

Temp retrofit micro dwellings

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