Green Insulation (for a little less “green” $)

For our last couple of projects in Cole Valley, 394 Frederick Street and 173 Downey Street, we wanted insulation that was effective and tight yet VOC (volatile organic compound) and Formaldehyde-free.

At the time, back in 2008, our best choice for the exterior was to use a concretious foam insulation called Airkrete that is shot in between the studs through a metal screen mesh to completely fill the voids and make an airtight seal.

In between floors and in the interior walls, we selected the Ultratouch recycled denim insulation – a non-toxic, non-flammable, pest-resistant cotton, really.

Both of those products worked great.  No complaints…except perhaps that both are pretty darned expensive compared with Fiberglass insulation.

Now, a couple of years later, we looked again and found numerous formaldehyde-free Fiberglass options for our 1566 Sanchez project that cost no more than the old toxic fiberglass insulation yet are very very cost effective.

We chose to use the Knauf EcoBatt product – an unbleached formaldehyde-free insulation batt with R21 in the outer walls, R38 in the roof and R30 between floors.

It looks more or less like raw sheeps’ wool and installs quickly…without busting the budget yet keeping the toxins (and the heat or cold) out.

Green is on it’s way into the mainstream!

SF has best Green Building Policy says WorldGBC

We knew that there was a reason we focused on San Francisco for our Green building projects!

This week, at the United Nations COP17 Climate Change Conference in Durban, South Africa, the World Green Building Council awarded San Francisco as the city with the best Green building policy.

Why?  Well, you can read the release yourself, but here are the key factors that were called out:

1. Monetary benefits: Incentives and rebates for retrofits to improve energy and water efficiency, as well as lower operating expenses such as reduced utility costs
2. Recognition: LEED and Energy Star certifications are now recorded by the city’s Assessor Recorders office; the city’s official record system
3. Information: Knowing how a building compares to its neighbors, a direct result of the Existing Commercial Building Ordinance
4. Tools: Collaboration between public and private sectors result in the Green Tenant Tool Kit
5. Capital: GreenFinanceSF is a commercial PACE program in place to provide secure capital for energy efficiency, water conservation, and renewable energy retrofits
6. High Standards: The Green Building Ordinance ensures that new building and large renovations are built to be sustainable and that obsolete inefficient equipment is replaced

We can certainly attest that these factors are true…well, mostly true.

The new Green Team in the San Francisco Planning and Building process did approve our 1436 Sanchez project for expedited processing since we were targeting LEED Platinum, saving us perhaps 3-4 months in the Planning process.

We have also benefitted from GoSolarSF‘s incentive programs for offsetting some of the cost of adding photovoltaic solar panels to our projects at 173 Downey and 1566 Sanchez.

And it is gratifying to know that our LEED status for both the 1566 Sanchez and 1436 Sanchez projects will be recorded on their titles when those homes are sold, lending a truly official imprimatur to their Green nature.

At the end of the day, it’s nice to know that we live in a city where the official policies are, in general, driven by trying to do what’s right, both for today and for the future – despite the country’s inability as a whole to get behind strong regulations to drive us towards a less toxic, more sustainable and smaller carbon and water footprint future.

New Life for Old Concrete

In keeping with the eco mantra of Reuse – Recycle – Reclaim to avoid waste, we broke up the old and ugly aggregate concrete back patio of the home at 1566 Sanchez (at the suggestion of our landscape architect, Scott Lewis)…

 

…and re-used the chunks to build a dry-stack wall that looks like stacked stone.

The new wall is not only attractive, but keeping the concrete on-site saved us dumping charges, materials costs which we would have had to incur to build a brand new wall, and reduced our carbon footprint by avoiding all of the fuel consumption for the trucks that would have had to haul it off.

Framing it on up…

Back in April, we finally got through the foundation work and rain and started framing the project at 1566 Sanchez.  Framing – or putting up the rough lumber that establishes the structure of the home and layout of the rooms – is usually a homeowner’s favorite stage because it happens FAST.

Within a couple of weeks, the whole structure of the home can go from how it used to be (for the last 132 years) to how it soon will be.

Here, before start of deconstruction of the original roof, we see these beautiful and long pieces of the original redwood.  Rather than dumping or recycling them, though, we kept them on site and will be making our new planter boxes from the wood that was originally in the home.

The garage gets framed out (with a bedroom behind plus a stair to the rear patio)

When the wall’s right next to the neighbor’s, you build the wall on the ground, finish and waterproof it, and then tilt it up into place

The new third story takes shape

The interior stairs to the new third story go in (but like with any project, the builder missed that the stairs were not supposed to have a wall underneath…luckily a quick and easy fix at this stage).

Here in San Francisco, though, Framing is not all woodwork.  To make structurally-sound homes that can withstand the impact of earthquakes, there’s almost always some steel I-beams involved, usually welded into a frame that will help keep the whole structure together when the shakin’ starts (and it will start…someday).  These beams are big, they’re expensive, they make it a pain to run plumbing and electrical (since you can’t drill through them) and they’ll probably save your home when the big one hits.

Solid as a rock

So how do you know that the new foundation you’re putting under your historic home is strong and up to snuff?

Well, following current building codes and building with permits that assure that an inspector will check them out at every step of the construction process helps.  As noted before, we’ve also used concrete with a high percentage of fly ash which makes the final hardened concrete harder while simultaneously requiring less water.

But another key process step is testing.  Yes, you have to test the concrete you’ve poured.  There are a number of companies that will do this for you, but the basic steps work like this:

1. Build your forms
2. Tie reinforcing steel bars (rebar) in forms
3. Decide on the concrete mix (i.e. % fly ash?)
4. Pour the concrete into the forms and…
   ALSO pour into a few cylinders for testing
5. Send cylinders to a testing lab
6. Wait standard curing time – usually 2-3 days
7. The lab crushes a cylinder and records the pressure needed to do so (i.e. 5000 psi)
8. If the number’s good, crush a couple of more and record the average
9. If the number isn’t what you need, you can wait another day or two and try again

What’s the worst case scenario?  The concrete never reaches the needed strength and you have to pull it out and try again…ouch.  Believe me – you do NOT want that to happen.

Zero lot lines = Slow foundations

Normally, the foundation pour for a small home like the one we’re working on at 1566 Sanchez could be done in a week.

Unfortunately, homes in San Francisco (and many other dense urban environs) are typically built as what are known as Zero Lot Line homes.  That means that the homes are built right up to the property line on each side, leaving anywhere from no space at all (for attached townhomes, for example) to an inch or two between the homes.

With a zero lot line home, your foundation is immediately adjacent to that of your neighbor’s.  When excavating down to add square footage and to build a new foundation, you’re most likely exposing your neighbor’s foundation where before it had been supported by your foundation or soil.  To protect the structural integrity of the neighbor’s home, you can use various proven techniques from rock to temporary wood walls to shore up their foundation and provide support so that it remains stable while you set up the wooden forms and the reinforcing steel bars (rebar) to prepare to pour your own foundation.

Unfortunately, this means that you can also only remove small sections of the shoring at a time to provide them with maximum protection while you pour the foundation in sections.

For 1566 Sanchez, we’ve done at least a half dozen pours of sections rarely more than 8 feet long at a time.   Unfortunately, you have to wait for the concrete to cure between pours, so the pours are a minimum of a week apart, but thanks to a super-duper-ultra-rainy winter, rain delays dragged that out further.

Nevertheless, we’re just about there!  We’re completely done with all of the walls adjacent to the neighbors on both sides and there’s just one foundation section to go and we are done with all of the structural foundation walls!

BOO. YA.

The big dig…

To add a bunch of square footage to 1566 Sanchez without taking up much more of the lot, we needed to make use of the basement area under the existing one-story home.

How to do that?  Excavate.  And excavate.  And excavate.

Above, our General Contractor takes a look at an area we just excavated where we noticed that the foundation under our neighbor’s recent unpermitted addition (at 1560 Sanchez St.) had no waterproofing at all and large voids through which you could see under their interior stairs from our side of the lot line.  Their concrete was also sitting on loose, uncompacted soil – pretty dangerous stuff.  Although permits are costly, it’s usually a good thing to adhere to the city’s building code and have the city inspect the contractor’s work…the code’s there for a reason.

Here we see from the street how the lower basement level façade has been removed and the CAT sits ready for another run in to lower the floor level of the dirt to prepare for the new foundation.

We’re pulling out a lot of dirt.  A lot of dirt.  Did I say a lot of dirt?  Yup.

Why put an electric car charger in an old home?

Because harmonizing the past, present, and future is what keeps an historic home relevant into the future.

On March 24th, 2011, British bank HSBC released an analyst report stating that there were perhaps 50 more years of usable oil to be extracted to utilized.  50 years.  That’s for power plants, home heating, and cars.  If we don’t plan for the end of oil, we do so at our peril.

Fortunately some people have the guts to do so…unfortunately, they’re only over in Europe and in the Middle East.

In March, a European Commission committee released a report recommending that all (not some, ALL) gasoline and diesel vehicles should be banned from EU roadways by 2050.  Somebody has a pair.  Perhaps those oil company-loving US politicians need to wake up and grow some.

Over in Abu Dhabi, meanwhile, they’ve been building Masdar City – the first zero carbon city to prepare for the inevitable future without oil.  Using solar photovoltaics and passive architectural shading and airflow management techniques, combined with a walkable community and efficient electric personal transportation systems, Masdar City is an experiment in urban planning for our future.

So while we’re not likely to go car-free here in the US any time this century since we don’t have the luxury of building an optimized city and infrastructure from the ground up, we can make some moves in the right direction…and for historic homes, that means, at a minimum, solar energy, water re-use, and planning for a future with electric cars.

 

…and we’re back!

Readers…sorry for the long absence.  Our first LEED Platinum project at 1566 Sanchez has been underway for a few months now, but the near-incessant rain has slowed progress to a snails’ pace.  Now that the sun is a shinin’ here in San Francisco, we’re back on track and within days of completing our foundation.

A flurry of catch-up posts and photos to come, along with updates to both our 1566 and 1436 project pages…

It’s great to be back!

Solar Roofs that Don’t Stand Out

While it’s easy to love what Solar photovoltaic roofs offer us in terms of clean and natural energy from the sun, it’s also easy to see that most solar panels are just not a very attractive architectural characteristic once those huge panels are mounted on the roof of your architecturally-authentic historic home.

Definitely not the way to keep a historic home looking historic.

There are, however, some options coming along that can help historic home owners go solar and yet keep the design integrity of their homes.  Two large photovoltaic technology providers, Uni-Solar and Dow Solar, have developed roofing shingles with embedded photovoltaic panels that can be nailed into a roof alongside regular asphalt shingles to create a roof that looks much more standard than one with large panel structures on top yet generates power to run the home.

Uni-Solar’s PowerShingle

and

Dow Solar’s PowerHouse

both offer what’s known as Building-Integrated PhotoVoltaic (BIPV) power to homes.  Granted that the Dow photo may have been poorly chosen since that house uses brown roofing shingles to go with the black PV shingles, but Uni-Solar seemed to have better understood the key benefit of their product…

Check out this installation with the Dow Powerhouse shingles on SmartPlanet.