Integrated Design I

I recently spent the night at a friend’s cabin in Ben Lomond.  The house was built in 1947, in a time an place when building permits, if required at all, were just a permission slip to build something, on a lot somewhere.  Details of the structure before or after were not considered necessary, except as an outline on graph paper, for the assessment rolls.

Things have changed.

Water, sewer, and electricity (but no gas) capacity have always come through public utility systems.  The heating “system” was a woodstove he added himself, in the 1970s.   Various shed-type room additions had been appended over the years, including a 15’x30’ accessory building (red-tagged upon a neighbor’s complaint two decades past, without resolution).

The property as it stands today is a testament to the necessity of a permit process, and more importantly to the idea of integrated design incorporating green building principles from the ground up.

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Passive Home Design: Forget the Furnace Forever

The Passive House is the future of homebuilding. It’s not the same as the passive solar concept from the seventies, but it’s not new. It’s a design system that is just starting to come into its own. Imagine this: a house that is so well built that it doesn’t need a heating system.

That’s right. Does not need a heater, no matter how cold the climate might be. From Fairbanks to Foster City, from Tahoe to Tiburon, every single new home that is in the planning stages right now can be designed using the Passive Home principles that have already been created. Over the last twenty years thousands of these homes have been built throughout the European Union, most of them in Germany and Sweden, where the winters get cold enough to put the design principles to a real-time test.

In recent legislation, the European Union has mandated that ALL new homes, and ALL renovations, meet the Passive Home standard. That is to say, by 2020, every single 2000 sf home on the drawing board will be so well built that its entire heating demand, even on the coldest day of winter, can be met with a hair dryer. That’s right, an ordinary hand-held hair dryer.

There is nothing magic about this, nothing unduly expensive or complicated except getting builders and designers to pay really close attention to certain details of construction. The essence of Passive Design is in very the well though-out and executed sealing air barrier between the interior and the exterior, including flawless insulation of the foundation, walls and roof.

There is more to it, of course. A perfectly sealed house needs a carefully designed ventilation system, one that transfers heat from exhausted air to incoming air, so there needs to be a “heat recovery ventilator” (HRV) installed. Sure, this equipment costs money, about the same as the heating system that you now don’t need to install. But, think of it: for the entire lifespan of the house, there will be no heating bill.

There are new insulating materials and wonderfully airtight windows available that make the Passive Home possible. They don’t have to add significantly to the cost of construction for a well-built home. The real difference is in the attention to certain details in the design and construction phase. The hard part might be in changing business-as-usual in the construction industry, by holding each segment of the industry to a higher professional standard. The results can be astounding. Think of it: NO HEATING BILL. End of story, at least, it could be. For more information, check the website http://www.passivehouse.us/ or ask your building designer about it. The future is already here.

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Building Solutions: a Case Study on Limited Energy Upgrade

Believe it or not, there are still some people out there who think that global warming is just a great big scare tactic. That we can just keep on business as usual, burning up whatever fossil fuel we need to just to keep comfortable. When wintertime comes, we just turn up the thermostat, live with the fact that some parts of our houses are hot, some cold, some drafty, none of it exactly comfortable. That’s winter, right?

No.

Chances are, your old furnace and poorly designed ductwork are to blame, because once these details are taken care of, comfort in your house in wintertime comes back to stay. Never mind that you might be using less gas and creating less carbon emissions—global warming is a myth, right?

So how about this—house warmer AND you spend, oh ,I don’t know, 25% less of your money heating the great outdoors. Money in your pocket, do you believe in that?

Well, you have to spend some. Not a lot, as dollars go these days, and you’ll get it all back in less than ten years in fuel savings. Maybe less than seven.

Case study by Building Solutions in Redwood City California (where the winters are by New England standards, pretty darn mild). Take an older house, 1850 sf, built before insulation was thought necessary, so there is none in the walls. It has its original 80% efficient gas furnace, and the original ductwork that went with it.

One key to understanding energy efficiency for older homes is the idea of “Test In”, meaning with blower doors and duct blasters, you find out up front where the warm air is leaking out of the forced air system, and through penetrations in the walls and plates. You find those leaks in the walls, and you seal them with spray foam insulation. Simple enough. Then you replace the old ductwork with new sized for delivery, and the old furnace with a new 95% efficient one, also correctly sized (both by the ACCA manuals, more on these later). Then you “Test Out,” for a data-based hard look at the results of the work done.

Results for the case study:
• reduction of heat loss through sealing up air infiltration 11%
• reduction of air leakage from new, well sealed duct system 23%
• reduction of lost heat load 7%
• increase in owner satisfaction with comfort level of house—priceless

This without insulating the walls!  Still don’t believe it?  Contact  Levi Blankenship at BuildingSolutions.com for how they did it.

My point is this: You can do part of an energy-efficiency upgrade, for a relatively low cost—in this case about $5,000—and reap great results. It doesn’t have to be all-or-nothing. Look for a BPI (Building Performance Institute) certified energy efficiency contractor in your area. Call them, see what they think they can do for you.

Or, you can hang an extra sweater by the door of your coldest rooms, and pay more than you have to for gas or fuel oil indefinitely into the future.

Your choice.

© David Hirzel 1/28/10

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Design and Construction Techniques to Use Less Wood

Thinking about adding something to your home—a new deck, a master bedroom addition, or a kitchen remodel? Given today’s bright focus on green building, let’s look at ways to get the same great result using less wood.

The most important thing you can do is plan your project carefully.  No matter how large or small it is, there are plenty of ways to avoid waste.

First, don’t build more than you really need.  If 150 square feet of new room or deck is all you need, why make it any larger?  Yard space for landscaping and recreation is just as important as finished living space, and probably easier to maintain.

As you move on to framing, be aware that some common practices sacrifice trees and energy efficiency, yet add nothing to the strength of the structure. You can use less wood, less time, less money in the framing by not using double trimmer studs and sills at window openings, 4×12 headers at openings in non-bearing wall, three-stud corners. Instead, employ Optimum Value Engineering or OVE and use studs placed at 24” on center rather than the common 16”, single rather than double top plates (bearing walls must have joists and rafters stacked above the studs), two-stud corners, and a variety of other practices. These practices can save up to 30% in lumber expense.

You can also consume less raw wood by working with engineered lumber. Engineered wood is made from small-diameter, fast-growing plantation farms and are usually straighter and stronger than solid-sawn products. Ask for products such as truss joist I-beams (TJIs), parallel-strand lumber (PSLs), oriented-strand board (OSB) and laminated wood products. These manufactured lumber products are all in common use today.

When you do build, build to last.  Most commonly used woods will not stand up well to insects or the weather, and all of them (unless especially treated) are subject to fungus damage when they gets wet and cannot dry out.  It’s critically important to understand which materials to use outdoors, and how important flashing details are where the construction is exposed to rainfall.  A 1” mis-cut at a crucial flashing junction can lead to thousands of dollars worth of damage in only a few years.  Water resistant finishes—paints and penetrating oils—are also important in keeping the wood safe from fungus damage.

There are a lot of manufactured products available now that take the place of, and weather better than, the wood used outdoors just a decade age.  Cement-based siding installs and looks like wood when painted conveys the same look.  There are a variety of composite decking materials that look much the same as, and last much longer than redwood decking.  Vinyl fencing is now available in a variety of styles, and has the added advantage of never needing paint.

Most molding profiles are now available made from plastic with wood veneer, that will cut, stain, finish, and install just like hardwood trims.  Beautiful “engineered” flooring of hardwood veneers comes prefinished and can be installed in much less time than hardwood nailed down strip by strip and sanded and finished in place.

There is a world of new products and techniques out there.  If you take the time to educate yourself in their proper application and installation, you just might help keep some of the trees in the forest, and some of the green in your pocketbook.

David Hirzel is a Green Point Rater and residential building designer serving the Peninsula and the central California coast since 1983.

(First published in San Mateo Times, August 13, 2009)

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