THINK INSIDE THE BOX by Allan Lynch by Stefan Bolduc

The meeting and event industry has rethought technology, program elements, room design and where and how groups meet. Advancing these changes is a society that has embraced a new style of creative collaboration with colleagues, actively participates in micro-lending for new enterprises and social causes via crowdsourcing and champions the growth in gourmet food trucks, as well as 􀏐lash mobs and pop-up events.

So, in the continuing quest for event hosts to appeal to a mobile, independently minded attendee, could the next big innovation not merely be out-of-the-box thinking, but a reinvention of the box? Speci􀏐ically, consider the potential role of shipping containers as actual pop-up event venues.

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Pop-up village in south-east London to house homeless families by Stefan Bolduc

The flats have cost £1,200 per sq m to make and fit out with kitchens, white goods and bathrooms, working out at £90,000 for each home. Harbour said building them in a factory rather than onsite allowed costs to be kept down. The lightweight timber construction has also meant savings, as the foundations only need to be half as deep as for equivalent brick-built blocks. They have a lifespan of 60 years and can be moved several times in that period and configured however the council needs them to be. A two-bedroom family home can be adapted to provide an accessible one-bedroom home for tenants with disabilities.

Planning permission on the site lasts for another three years. “The typical length of temporary accommodation is 18 to 24 months, so in the time that they are here we hope there can be two cohorts of people who can move in then be moved out and securely housed,” said Osama Shoush, the project manager. “As the time comes to an end we’ll manage it so that we won’t have to evict anyone.”

Not everyone has welcomed the new addition to the high street. Denise Flintham, who owns a shop across the road, said the buildings were “a total and utter eyesore”. However, other residents are more enthusiastic. Serophina Gregory, an events and social media manager, said: “I think it’s great and a really good idea that they’re providing a safe home for homeless people. Too much of London is being taken over by big developments that don’t benefit the community.”

Harbour said other councils had shown an interest in the project and interest was likely to grow once the flats were finished. He said after the Y:Cube was unveiled “people wanted to know if they could get one for their garden for their children to live in”. For the council, although the buildings are temporary, they are part of its long-term plan.” 

Shoush said: We don’t want the temporary use to be something that happens and then ends when the regeneration happens, we want it to be the start of the regeneration.”

A council in south-east London has created what it describes as “the UK’s first pop-up village” to house families who are forced to live in B&Bs in other parts of the capital.

Rapidly rising property prices and rents, combined with the loss of social housing through right to buy, have put councils under growing pressure to find new ways to help people off their housing lists.

A council in south-east London has created what it describes as “the UK’s first pop-up village” to house families who are forced to live in B&Bs in other parts of the capital.

Rapidly rising property prices and rents, combined with the loss of social housing through right to buy, have put councils under growing pressure to find new ways to help people off their housing lists.

The two-bedroom flats on Lewisham high street will provide temporary accommodation for families who are living in B&Bs. That type of accommodation “is not only not good, it is expensive”, said Jeff Endean, the council’s housing strategy manager. Rents on the new homes have not been finalised, but are expected to be set somewhere between social rents and market rents, said Endean. They will be paid through housing benefit.


The factory-built flats arrived on the site late last year, each home coming in two pieces: one is the living area with all of the services and kitchen built in, the second provides the bedrooms. The homes have been designed by Rogers Stirk Harbour + Partners, the architects behind the YMCA’s Y:Cube – individual units for single people in need of housing. Each home in the Ladywell pop-up village is three times the size of the Y:Cube, and the architects say it is a step up from that design.

“Our only constraint is the volume you can get on the back of a truck and get round the country,” said Ivan Harbour. The architects have pushed things to the limit, building homes that are bigger than the London space standards, with high ceilings that Harbour said “have the scale of the ground floor of a Victorian house”. 

Each two-bedroom home exceeds the London space standard at 75 sq m and includes a storage room big enough for some estate agents to attempt to pass it off as a bedroom. The flats are well insulated and will cost just £10 a month to heat in winter months. Floor-to-ceiling windows bring in lots of natural light, and large balconies add on a huge private outdoor space for each home. Kitchen work surfaces are made of expensive but hard-wearing Corian, while MDF panelling on the walls mean that interiors can be revamped easily and cheaply between tenancies. The bright cladding outside can also be replaced if they are moved somewhere where they need to be more muted.


The Future of Social Housing: Urban Low-Rise, High-Density Developments by Stefan Bolduc

   As cities around the world struggle with solutions to the housing shortage that faces many communities, one urban building typology has been floated for decades that might increase housing units without reducing quality of life: low-rise, high-density. Emerging in the 1960s and 70s as an antidote to the severe “tower in the park” model offered by Le Corbusier and others, this housing typology had the potential to overcome some of the downsides of massive urban renewal in its emphasis on livable scale and community context.


As cities around the world struggle with solutions to the housing shortage that faces many communities, one urban building typology has been floated for decades that might increase housing units without reducing quality of life: low-rise, high-density. Emerging in the 1960s and 70s as an antidote to the severe “tower in the park” model offered by Le Corbusier and others, this housing typology had the potential to overcome some of the downsides of massive urban renewal in its emphasis on livable scale and community context.

by Stefan Bolduc

Andrew Curry has an interesting article about how more than any other single innovation, the shipping container epitomizes the enormity, sophistication, and importance of our modern transportation system. Invisible to most people, but fundamental to how practically everything in our consumer-driven lives works. "Think of the shipping container as the Internet of thing," says Curry. "Just as your email is disassembled into discrete bundles of data the minute you hit send, then re-assembled in your recipient's inbox later, the uniform, ubiquitous boxes are designed to be interchangeable, their contents irrelevant." Last year the world's container ports moved 560 million 20-foot containers. Even cars and trucks—known in the trade as "RoRo," or "roll-on, roll-off" cargo—are increasingly being loaded into containers rather than specialized ships. "Containers are just a lot easier," says James Rice. "A box is a box. All you need is a vessel, a berth, and a place to put the container on the ground.

Consider the economics of a T-shirt sewn at a factory near Beijing. The total time in transit for a typical box from a Chinese factory to a customer in Europe might be as little as 35 days. Cost per shirt? "Less than one U.S. cent," says Rainer Horn. "It doesn't matter anymore where you produce something now, because transport costs aren't important."

Yes, Unvented Roof Assemblies Can Be Insulated With Fiberglass – A WUFI Post by Stefan Bolduc

An interesting post for the good folks at 475 High Performance Building Supply:

A post on August 21st, 2015 on, Martin Holladay asked the question, Can Unvented Roof Assemlies Be Insulated With Fiberglass?  Martin’s post focuses on the marketing of Owens Corning’s ProPink Unvented Attic Insulation System.   The Owens Corning system is only allowed by code in zones 2B & 3B with tile roofs.

And even still, Joe Lstiburek is quoted in the post saying “I don’t believe it will work without a vapor diffusion vent,” …“It’s too risky…”  Martin, then quotes the response from Achilles Karagiozis, Owens Corning’s director of building science: “Absolutely,”…“We are stuck with the code as written. It was written a long time ago, and it was written for one particular industry: the spray foam industry. Joe [Lstiburek] worked on that.”

Later Martin Holladay notes:

Owens Corning says that this system works with asphalt shingle roofing in Climate Zones 2B and 3B — but using asphalt shingle roofing on this type of roof is a code violation. “We all have to follow code, but at the same time, we can provide code officials with the engineering behind our recommendations,” Karagiozis said. “If we feel it makes sense, we will help the builder to provide information to the code official to get approval. We take these WUFI files.”

At 475 we agree with Joe Lstiburek, that we must make safe and robust enclosures.   And 475 agrees with Owens Corning, and Achilles Karagiozis that the current code was written for the spray foam industry and we can make safe unvented roofs with fiberglass insulation given the right approach – and that educating code officials for approvals of such systems is essential.

So building inspectors and plan examiners please take notice: we want to work with you and show we need not rely on toxic and unreliable spray foam but can instead safely and robustly use fiberglass insulation.   But must we be stuck in climate zones 2B & 3B?  What about the zones where most of you live and work: 4, 5 and 6?

In this post we will show, that while the ProPink Unvented Insulation System may provide a safe roof in zones 2B &3B, if we instead combine dense fiberglass insulation (batts or densepacked) with INTELLO smart vapor retarder and airtight membrane we can make safe and robust unvented roofs in climate zone 6!

Code pushes the envelope – IECC vs IRC/IBC

Codes should provide the minimum parameters for performance, safety and durability. For instance IBC# does indicate that wood moisture content should be below 19% when installed, a dry roof (no condensation or leaks) is a healthy, structurally sound roof.  However since the Energy Code continues to increase R-value minimums, the risk of condensation/moisture accumulation in roof assemblies in cold and mixed climates has increased too. The only solution the code provides to this moisture drive issue is to add “sufficient” air-impermeable insulation below the deck to theoretically keep protect the sheathing from condensation/moist air-currents. None-the-less, it is known that an air-impermeable insulation layer will only work as an air barrier/vapor control layer, if it is also installed as one (board seams taped, spray foam mixed/applied correctly). This work not only should be performed meticulously, it should be verified by a blower door. However, if the installation is sloppy or not durable (foam shrinks – cheap tape is used or worse – caulk), the “airtight” insulation will not be airtight for very long. If the airtightness fails, then the risk of damages/rot or mold in the assembly increases substantially. You might get lucky, but if things go wrong – the consequences are costly (repairs, healthy problems, etc).

IECC 2012 took a first step to acknowledge these issues, and is mandating a verification of the airtight layer installation at 3.0ACH50 (Unfortunately, a residential code mandate only, so far, that a number of states have adopted). And we do see good designers, even when using SIPs, acknowledge the importance of sealing the interior seams of this airtight insulation material with airsealing tape (see photo on right).

We have gotten assemblies approved in several jurisdictions while working with the authorities having jurisdiction (AHJ), such as the building inspector, to show that one can design and build a roof that has air-premeable insulation (fiberglass, mineral wool, sheepswool, cellulose, etc) that can be declared“air-impermeable insulation” with an air barrier which is also a (very) smart vapor retarder: INTELLO Plus as an integral part of the insulation installation. From experience, 475 knows that with the Pro Clima system, one can quickly make a very durable airbarrier. Every month we have dozens of customers that blow-by 3.0ACH50 and many reach 0.6 or better for Passive House certification – with more and more hitting 0.3 and lower. Since this membrane is part of a complete airtightness system from Pro Clima with TESCON tapes, gaskets, and adhesives – we know that the contractors can reliably build and roof assembly that is durably airtight (100 year lab tested tape) on the interior and can verify this with a blowerdoor test. Giving the AHJ confidence that the WUFI’s as shown below, can be relied upon – because without a certain level of airtightness, no reliable performance (not with INTELLO, not with foams).

If Owens Corning ProPink Boxed Netting is a Step Forward, Then INTELLO is a Leap Forward

Joe Lstiburek called the ProPink Boxed Netting in the GBA article “brilliant” and “fabulous”, and Martin Holladay notes the netting is well designed.  Both may be the case.  But it should be noted that it is this netting material that is the cause for the system’s narrow reach.  The netting is vapor open and not airtight.  Airightness is to be provided outboard of the insulation at the sheathing with canned spray foam, as GBA notes.   Consequently, if the ProPink system is installed in a cold climate, the conditioned air can easily reach condensing surfaces and cause moisture damage.  (And of course, airsealing is so important because air can carry 100x as much moisture into the structure then diffusion will – leading to damages much faster.)

But if the fiberglass is held in place with INTELLO membrane – the insulation has vapor control and airtightness inboard, where it should be – the conditioned air stays in the conditioned space and away from condensing surfaces.

WUFI The Challenge

To extend the use of non-foam insulated attic and cathedral ceilings with asphalt shingles, we have WUFI-ed a challenging roof in climate zone 6. The assembly has vapor closed, light colored asphalt shingles on the exterior over OSB sheathing. It avoids vent baffles, ridge vents etc – so considerably faster to construct both for new builds as well as renovations (details are available here). The required R-49 in Burlington VT (climate zone 6) was made with dense fiberglass.

We then assessed the performance of such roofs with different interior airbarriers, each with different vapor permeability profiles:  ProClima INTELLO Plus as the vapor variable retarder (0.17 to >13 perms), 6 mill polyethylene (fixed 0.05 perms), painted ‘airtight’ drywall (15 perms) and siga majpell (fixed 0.7 perms).   We want to know if air-sealing the insulation with these materials on the interior will lead to safe assemblies (ie once with some reserves to deal with unforeseen moisture) , that are easy to build or to retrofit.

Since we modeled the worst case roof, steep north facing, 10:12 pitch and light grey shingles – the solutions shown is a foam free cathedral ceiling that can be used throughout climate zone 6*, that use a limited number of readily available materials in a cost effective, durable way, with repeatable, easily verifiable methods that work for any orientation or shingle color. We want a roof with dependable performance: one that has reserves so it can deal with some small airleaks (at 3.0ACH50 small leaks can be expected).  Another objective is to have an assembly that does not require foam and is easy to install – applying batts in between rafters can be done fast and cost effectively – the cost of INTELLO Plus and TESCON VANA is less then the minimum required layer sprayfoam – and does not require biohazard suits to enter the enclosure, nor do homeowners have to evacuate the house.

In this WUFI study, we did assume a airtight construction with only minor airleakage into the insulation layer.  (Contractors must blower door the building and confirm airtightness.) The first graph below show total moisture content over 5 years from different approaches.  The assemblies sealed with 6 mill polyethylene and siga majpell on the interior are getting more damp every year – this is an indication one can expect issues in those assemblies over time (rot/mold).  The moisture content in the INTELLO Plus roof decreases and stabilizes at a safe level in year one.


Do note that the drywall roof goes off the chart every winter. This should be a red flag as well. If we look at the graph below, we see that there is condensation on the OSB – it’s RH maxes out in November and it stays wet the end of May – so even though this roof dries out every summer, there are concerns for structural degradation and mold in this roof.

We should then also look at the relative humidity thresholds that ASHRAE 160P has defined. It states roof assemblies will be safe and reliable if 30 day averages of relative humidity do not exceed 80%. And if it does exceed 80%RH,  then the temp should be below 40F – which is too cold for rot and mold to occur. The graphs below show that with airtight drywall the sheathing is saturated in the winter.   But with the INTELLO roof, only when the sheathing is extremely cold – temps in low single digits – that the OSB sheathing goes above 80%RH.  This spike in RH can be explained, because when it is that cold, given laws of physics, materials hold less moisture, hence the RH briefly increases during those cold snaps.

A second safety check can be done in this case. It is generally accepted that if equivalent moisture content of wood stays below 18M% it will not degrade. For OSB we like to stay a bit lower – 15M% is a more conservative threshold, as it allows for some reserves in the structure. Below is the M% shown for the OSB sheathing. Except for winter #1 (when there is some residual construction moisture being pushed into the OSB) – the OSB stays right below 15M%.

Drying reserves – sufficient at R49, convincing AHJ and can you do more?

This WUFI Pro modelling shows, that in climate zone 6 – unvented R49 asphalt shingle covered roof can be build without foam, and have a sufficient amount of reserves that enable it to cope with some unforeseen moisture ingress. As shown, it does need a vapor variable membrane that modulates from very vapor closed (0.17 perms) to really permeable (over 13) -> INTELLO Plus, that is installed in an airtight, verified manner (TESCON VANA tapes, gaskets, blowerdoor), with fibrous insulation that completely fills the bays (class I install for batts, density checked for blow-in insulation). For any cases that go beyond R49 or require assistance convincing the AHJ in your specific location/climate zone – please contact us as we are happy to assist with additional WUFI models.

We applaud Owens Corning’s efforts to to develop new and inovative solutions that reduce our dependence on spray foam.  INTELLO is a great partner with fiberglass to move this approach across most of our climate zones.

If you are an architect,an insulation installers and contractor can design and construct high performance roofs – that make plan examiners comfortable.  If you need additional support or WUFI files for your location – please contact us.


# Moisture content max per JM Spider page 2  and IBC 2304.7 Floor and roof sheathing.

* exempted are extra challenging constructions: greenroofs, high altitude locations or heavily shaded locations – please contact us for specific recommendations for such assemblies.

Note: Proclima INTELLO is included in Fraunhofer material menu in WUFI Pro, including it’s optimized vapor variable properties (see graph below)

Peer-to-Peer Solar Startup by Stefan Bolduc

We subscribe to a great blog by Brandon Donnelly called Architect This City. It pops in the mailbox every Sunday at 10pm and we there is always something great in there. Below is this weeks interesting story.

Airbnb is a platform that connects people who have extra space with people who need space. It’s a peer-to-peer hospitality company.

Yeloha, which is a startup I just discovered today, is a peer-to-peer solar company based out of Boston. 

In the same vein as Airbnb, it connect people who have extra roof space (that’s suitable for solar collection) with people who want to buy solar energy (but may not have a solar friendly roof).

Here’s an image from their website that explains how it works:

Basically, if you have a solar friendly roof, Yeloha will come and install solar panels on top of your place for free. You get to keep some of the energy that’s generated (about 1/3 apparently) which becomes a credit to your electricity bill. You are then known as a “Sun Host.”

The remaining energy gets fed back into the grid and, if you don’t have a solar friendly roof, you can purchase this excess energy, which also results in a credit to your electricity bill. The solar electricity is less expensive than the regular grid electricity. In this case, you are known as a “Sun Partner.”

I think this is a pretty neat idea. Neither party has to pay anything upfront. Both parties save money. And the result is more solar through a distributed and virtual net metering setup.