Making Decisions Under Pressure

In our last major post we discussed how improperly sized and installed HVAC equipment can result in a quicker failure than normal.  We left you hanging with the question of how to equalize the pressure in your rooms so that they don't turn into a big wood and gypsum balloon.  If you recall:

• More air goes into a master suite than out;
• This is a result of no escape paths;
• Air backs up into the furnace;
• The furnace gives up and dies during a cold snap.

So how do you equalize this pressure?  The most common way is with a 1" door undercut.  Most homeowners find these unsightly, on top of which they are sized before carpet is installed.  Once carpet goes in place all of the 1" is used up and no other outlets are given.  Some might say to let the pressure leak to the outside.  To this we say "bad builder, no burgers for you".  If your pressure is leaking to the outside, where is the furnace's makeup air coming from?  Outside!  Let's try a different approach.

In order to equalize the air pressure, we need the same amount of air going out of a room as is coming in.  The idea is that warm enters a room and forces the cooler air out which goes to the furnace, gets warmed, and the cycle goes again.  If air is to leave a room, we need a space for it to happen.  There are four common ways to make this happen.

1. Door undercuts have been discussed.  These are generally not aesthetically pleasing.

2. High/low relief vents.  This entails cutting a hole high up in the wall of the room between studs.  Between the same studs a hole is cut near the floor in a hallway or other common area.  This allows air pressure to move freely.  Grills over both cuts give a more expected appearance.  This approach may not give complete privacy as sound can travel a little between both spaces.

3. Jumper ducts in the ceiling.  These are leftover pieces of flex duct used to create a connection between bedroom and hallway in the ceiling.  It is similar to the high/low vent but less obtrusive and slightly more private.

4. Dedicated return.  This is a connection in the ceiling of a room right into the main return for the furnace.  This allows for the most direct air balancing and the most privacy.  Depending on the distance to the furnace it may be noisy.  Further is better.

Bear in mind that these measures are only necessary in larger rooms that can be closed off from the main living area.  Smaller bedrooms and bathrooms don't gain enough positive pressure.  Great rooms and dining rooms are generally connected to the majority of the living area.  A media room or bonus room that is separated by a door and has more than one supply may benefit.

If you want to give it a down and dirty test, close all doors in the house and fire up the blower.  Then slowly open each door.  If it presents any resistance then some sort of relief is needed.  If you want to be even more savvy, get hold of a Duct Blaster and someone who can run one.  This will give you an accurate test of where your problems will be.  Then whip out your slide rule and estimate a size for pressure relief.

If your house is especially tight, you will definitely want to install a heat recovery ventilator.  This system brings fresh outside air into the furnace while tempering it with the heat from outgoing stale air.  In some cases this can be your blower with an in-line heat source providing comfort.

Istockhouseplans recommends doing away with ducted systems altogether.  For better comfort consider a ductless heat pump, radiant floor heat, or electric soft heat.  Or do away with heat sources completely and join the PassivHaus movement.

Lengthy Topic

Today's little bonus post is brought to you by the American Wood Council and their span calculator at
http://www.awc.org/calculators/span/calc/timbercalcstyle.asp

Don't get to excited, this is not a full structural calculator.  It is, however, a great alternative to checking span tables and they have an iPhone version, handy for field specification.  Mind the deflection.

Happy designing,

Istockhouseplans

Does your equipment blow or suck?

Happy twenty-'leven from Istockhouseplans to all of our friends out there in cyberland.  We hope your holiday was interesting and thoughtful.  A quick note about our year-end report: despite the down economy, our books show that we made twice as much in 2010 as we did in 2009.  Thanks to everyone who made that possible, and here's a toast to all of you that your books did and will do the same for 2011.

Now, to the topic at hand.  A strange thing happened over the holidays.  The building that we work from is heated with a forced air gas system, commonly known as a gas furnace.  It was recently insulated and air-sealed.  Somebody kicked a heat register shut and the tighter house acted differently.  In this case something happened.  Before, nothing would have happened.  This lead us to a little investigation.

First off, a house is a closed system but not entirely.  It is impacted by the outside environment to some degree.  The more a house is insulated and air-sealed, the more you reduce the impact from and to the outside environment.  This means you get more reaction within the house when something changes.  What changed in this case was air pressure.  By shutting a heat register, suddenly more blown air is directed to other registers.  In a tight house, this air is supposed to balance by going into the return register, through the furnace where it is warmed, and back through the registers.

Now imagine that air that is blown into a bedroom can't return to the furnace.  That is, it is blown in but there is no way for it to get out.  This might be the case where there is carpet and the door is shut leaving a paper-thin space between the bottom of the door and the floor.  A little air will get out but now the system will be imbalanced.  Kind of like filling a balloon.  More air goes in, but none comes out.

But the air has to go somewhere.  With a balloon, it will stretch the environment.  Unfortunately drywall is not as pliable as rubber.  So the air goes where it can, that is through tiny cracks.  At some point the room reaches critical mass for pressure.  This is when things start to happen.

Much like a pipe that has been corked off, the air stops flowing through the duct.  It might back up and force more air through another register up or down the line.  If it is a dedicated duct run with no other outlets, it will back up into the furnace.  So what you have is two pressurized environments doing battle.  Try this: grab a straw and a loved one.  Each of you put one end of the straw in your mouths.  Now both blow as hard as you can.  Cheeks will turn red, eyes will bulge, and finally someone will get a mouthful of the other one's air.  This is called system failure.

In the case of your furnace you could simply blow a duct.  However with today's tighter duct runs, the weak spot becomes the furnace, most notably the blower fan.  So the fan has back pressure causing two forces to exert their will upon it.  At some point the fan gives in and stops blowing.  The furnace still warms but the forced-air part has been taken out of the equation.  This tends to happen on the coldest day of the year on a Saturday night.

Granted, one single room is probably not going to have major adverse effects on the HVAC system.  But imagine an 1800sf three bedroom house.  The furnace is likely to be oversized (60kBtu) and the master bedroom might have two heat registers due to it's size (~200sf) as well as a heat register in the master bath and maybe one in the master closet.  The door is closed and there is no appropriate 1" undercut.  In fact, you would need about a 4" undercut.  Air gets backed up in the room.  Your head hurts.  Then the furnace quits.  You thought it was just the end of the cycle but it doesn't turn back on and the temperature continues to drop.  At first you assume a power outage but the VCR clock is still blinking '12:00'.  The next day it's even colder in the house so you call the HVAC tech.  He says he'll be out there sometime between 9a and Friday.

The bugger is that your house was built last year.

Before buying a new house, ask if the system was properly sized.  There are a slew of manuals and related software out there for professionals to use.  As a builder, always ask your HVAC tech how they arrived at the necessity to install an 80kBtu furnace.  Also ask how they are going to mitigate zonal pressure relief.  If they stare at you or stutter or write it off, hire someone else.

In the meantime, Istockhouseplans recommends not using forced air systems.  We push for hydronic floor heat, so called 'soft' heat (electric baseboard) and mini-split heat pumps.  All of these systems take less space and use less or no air.  They can also be sized more appropriately than a furnace can.

Don't forget to check your filters and consider cleaning your ductwork.  Oh, and if your head hurts in your bedroom, simply try opening the door.  Stay tuned for next time when we'll look at some more zonal pressure relief options.

Some comments on Real Estate Agents

First off, we want to say that we appreciate realtors very much for the upstream job they do in selling our plans.  Granted, they don't sell our plans directly, but they do sell the building that the contractor created from our plans.  But there are some things that we'll never understand.  Most likely this can just be chalked up to personality types, life direction, etc.  Sort of like we will never understand the Chinese culture.  If you are a realtor, we invite you to respond with intelligent answers in an attempt for open communication.

1. Why does all of your marketing material have your face on it?  Why do we care what you look like?  Some of you are not very attractive, even with glamor shots and Photoshop^TM.  Maybe you say it's because your face is your image and it's how people remember you.  We think you guys all look the same.  Same with insurance agents and lawyers.  But the contractors who build our plans don't advertise with their face.  As building designers, we don't advertise our face (we know better!).  Plumbers don't, electricians don't, and the guy who lays the carpet doesn't.  So why do you?  Is this the way it's always been done?  We'll bet if you used something other than your face, you might get noticed as being unique.  Just a thought.  Maybe an icon of a house with some zoom lines around it that says "I make quick sales".  That's what we really want anyway, not your face on a lawn sign.

2. I understand that not anyone can get a realtors license.  You've got to have patience, a study guide, and $500 to take the test.  So why on the test do they not mention anything about house styles?  I swear, every other house listed in our local paper is a 'bungalow'.  I know for a fact that there are not that many bungalows in the state.  Is a bungalow sexy or something?  Or is it just a cop-out because other housing styles aren't known?  We've seen tudor, craftsman, prairie, ranch and victorian all listed as bungalow.  Another one that crops up is 'old Portland style'.  What!?  Which style?  This one really is a cop-out.  It's used a lot on prairie cubes and bungalows where the word bungalow has been already overused.  If I may suggest, could you research housing styles and figure out more than five?

3. Why did we receive junk mail and solicitations AFTER we bought our current abode?  Did you think that we would be so impressed by a circular with your face on it that we would immediately want to buy another home?  Like we could afford that?  Instead, the timing of your mailer was so backwards that we looked at it, made fun of the timing, and then recycled it without another thought.  No, I don't know who it was, you all look the same.  It would be understandable if Istockhouseplans chose to leave catalogs on construction sites.  Builders tend to build more than 1 house every 3-5 years.

4. Maybe the general public can't tell, but some of your fliers for houses are less than spectacular.  The fliers themselves sometimes use gaudy colors or err on the other side of no bling at all.  AT ALL.  We do want to see more than a list of 'amenities' in 10 pt font and 4 1"x1" photos of the house.  But we don't want to see what looks like a beginner's guide to every option in Print Shop^TM.  A simple left margin graphic, 3 colors, and appropriate font size are a good place to start.  And make the price tag big enough that it can be seen through the 'take one' flier box, in the rain, from the car, at the curb.  We are not pleased with having to open the door in a downpour to grab a flier (or 110 degree temps for those in SoCal).  The mere act of touching a flier will not increase the chances of buying a house.  Folks who are driving through a neighborhood they haven't been through before do not want to write down an address to look up when they get home.  They'll forget.  Or they will merely go the next house with a post and shingle and look at the flier through the glass.  If they feel they can afford it, they'll risk the elements to grab a flier.

5. Photographs.  This should be 'nuff said.  First, include them.  When a flier says 'Too new for photos', this is immediately understood as laziness.  "But I just have to get signs and an RMLS listing up today!"  Good, go get some photos first.  Years ago we saw a website of a realtor who was making fun of other realtors for their photos.  If you can be seen in the bathroom mirror as you run by to take a photo, it's worth a retake.  If the neighbor's trashy car is visible through living room windows, it's worth a retake.  Second, please stage your photos.  This does not need to be spendy.  Clutter in the house MUST GO.  Make your client clean up, get a storage space, or explain to them their house will take 6 months to sell.  Being able to spot a box of 'toys' in a master bedroom photo will make us ask for new carpet.  Just in case.  No, steam cleaning won't be enough, thank you.  And lighting is a must.  Invest in some shop lights on a stand and use them for INDIRECT lighting.  Perhaps you could consider a fish eye lens.  Nothing dramatic, but have you ever tried to photograph a small bedroom or bathroom?  It's almost impossible to see the whole thing.  A subtle fish-eye style lens with 120+ degree views could help.  A lot.

Now we understand that home designers giving sales advice to realtors is similar to realtors telling us how to design houses.  So be it.  Consider this to be some helpful advice and tips from our years of experience in the housing industry.  Feel free to leave comments.  If you'd like to discuss more, email us.  Without your face.

You're fired!

In searching for some material on fireblocking, we ran across this thread on the DIY Chatroom.  Indispensible material.  This is generally the bane of do-it-yourselfers and code officials alike.

http://www.diychatroom.com/f98/how-fireblock-framing-37190/

Istockhouseplans is currently working on trying to fireblock a double 2x4 common wall with raised heel trusses.  We'd like to rock the wall all the way up and then hang the trusses but are unsure that the hanger would achieve strength through two layers of 5/8" type X drywall.  A more viable option would be to nail a 2x4 ledger through the sheetrock into the walls studs.  This would require 1.5" + 5/8" + 5/8" + 1" embedment = 3.75" nails.  While 18d nails might not be common, this is going to require a bunch of hand driven 20d nails.   Those won't exactly fit into a power nailer.  The other option is multiple 2x16 blocking between trusses.  Not really an option though.  Maybe stacking 2 pieces of 4x8 would do it?  Does anybody have input?

Water, water everywhere

What would life be without good old H-2-O?  Dead, that's what.  If a little water is good, more should be better, right?  If you've been around the block even once you know that the standard answer to this formulaic question should be 'no'.

And of course it's no!  Especially when we consider your house, your biggest investment, your protection from the elements, prying eyes, and the marauding huns.  Why do builders let water pile up on a wood subfloor, leave their materials in the rain and mud, and install insulation and drywall over wet wood?  How would they feel if their truck was built this way?

Building in the rain.  In some parts of the country, this is a fact of life that is unavoidable.  If it takes 3 months to frame a house, you are guaranteed a few rainy days.  Since no one (not even weathermen) can accurately predict the weather beyond the next day, it is impossible to completely frame a house dry.  Arizona, sure.  Not in the Pacific Northwest though.  But there are steps that can be taken to keep things as dry as possible.  First, don't plan to build in January.  Second, invest a few dollars in cheap insurance.  If you are building an elevated wood floor (that is, a crawlspace not a slab), make your last step include a giant paint roller with a long handle and a discounted bucket of 5 gallon paint, color unimportant.  This will protect your wood floor from standing water.  Walls go up, roof goes up, and then sheathing as soon as possible.  If there will be any amount of lag time getting the finish roof on, again paint the roof deck.  The problem here is that there are always spaces between roofing panels and water will leak through.  The worst spot is the peak, especially if a ridge vent is planned.  This gives a beautiful 6" wide by 20' long space for rain to come right in.  If you have a butterfly roof, don't build in the rain as this would make a funnel.

Finally, I don't care how tight your schedule is, buy a $13 moisture meter from Harbor Freight and don't do anything else until the moisture content is below 19%.  Since the aforementioned tool has an accuracy rating of +/-2% for wood, go for 17%.  Why 19%?  Most mold and fungus will not thrive below that and most insects will move out.  It wall also allow better equilibrium in the wood resulting in less drywall cracks and creaking of the home.  Further, it will reduce the amount of moisture trapped in the walls.  Even further, some codes require this.

Storing your materials.  Too often we go to construction sites and see a pile of 2x6 sticks sitting in the mud getting rained on.  Double you tee eff.  How is this okay?  What part of this makes you feel good?  If you were a pig or a toad, maybe,  Spend a few bucks for some pallets to keep your wood off the ground, then get some tarps or used billboard vinyls.  "Why would I spend hundreds on this?"  Hundreds?  No, less than that.  Did you even click the link?  A 10'x30' used vinyl is $60.  And you spend less than a hundred on this to get your moisture content down and save thousands on a callback.  Please don't be that short-sighted.

Think of it this way; the less moisture the wood takes into the house, the less time you need to wait for it to dry out.

Protecting your product.  Your product is the house and it's only worth the amount of trouble free time it will stand.  If moisture gets into the wall, the value ends.  Your goal is to manage the moisture that gets into the wall.  Not to keep moisture out of the wall, but to manage it.  It will get in.  From the outside.  Unless you are installing double welded steel siding, wind and thermal will drive moisture behind the siding.  At this point you have two options.  The first is to pretend it doesn't happen.  The second is to manage it.

So you've decided to manage your water issue.  The first step is admitting you have a problem so you're already on the way.  The second step is called a rainscreen.  There are several off the shelf products that can achieve this concept.  You can also use scrap plywood on site to create 2-3" battens and manage the water.  The idea is that the water that gets behind the wall then drains in a wide enough plane to not get stuck via capillary action and then drain out a screen at a bottom.  Water that freely drains is no longer available to stick around via surface tension and find crevices and cracks in your construction and seep into the wall.  Water in the wall can wet insulation, rendering it useless.  It can also harbor mold, mildew, and insects, hazarding your house and it's occupants' health.  If you have any lick and stick fake stone veneer, this is tantamount as the stuff is like a sponge.  It will readily take in water and hold it.  When the sun comes out, it will be driven back and then be held against your sheathing or building paper.  Compounds in the mortar then eat away at the paper and the moisture is free to roam about your wood sheathing.

Getting it right.  Contact Istockhouseplans for CAD details about how to handle this moisture.  We can spec out a rainscreen for you and make sure your final product is the best possible.

Hey baby, what's your... sign?

One of our local builders that we team up with, Cutting Edge Homes, is in the process of building some of our latest drawings.  Clackamas County is showcasing his homes for energy efficiency and has invited commissioners, legislators, and the general public.  The idea is to show off some energy efficiency measures and help folks understand what they should expect in new homes.  In this case is improved air sealing, improved insulation, tankless hot water heaters, and one unit with ducts inside the conditioned space.

We thought the event made perfect sense to flash a little leg, as it were.  After all, SOMEbody had to design the energy efficiency into these things and make sure they were going to exceed code.  So we had some lawn signs made up and stabbed them into the dirt on the jobsite.  You can see that our design prowess is not just limited to buildings, but advertising as well.  Perhaps.

The event will be November 10th at 3p at 14848 SE Arista Dr. Milwaukie, OR.  Come out and see what things are happening and to introduce yourself.

Go Green, Go Small

The Oregon Department of Environmental Quality (ODEQ) released a report today on an evaluation of waste prevention practices using life cycle analysis.  The report focused on 30 different measures and the impact they could have on our environment over a 70 year span.  We thought some of these measures might fare favorably.  Such include advanced framing, using salvaged materials, drywall clips, and other such resource efficient methods.  Of all the measures focused on though, the winners were smaller homes and multi-family living.  This would make sense since the measures we favored would tend to have more of a point of use impact whereas the clear winners would have more of a lifetime impact.  You can read the full report on ODEQ's website.

In this case, smaller home means 1149sf, half the size of the national average.  Istockhouseplans finds this rather exciting since our average designed house size is tending that direction.  We noted last December that average house size has peaked and is on the slide.  While not all the chips are falling immediately into the tiny house movement, it's encouraging to see the push this direction.  We hope that large home builders will be able to reduce their house sizes by using some of the techniques that the tiny house design community has put forth.  We will continue to work on our plans adding more 700sf and smaller plans as time allows.

Tiny+

Istockhouseplans seems to be creating a middle ground of homes in our arsenal.  We have composed quite a little group of tiny homes, by our definition 600sf and less.  With such homes as the Albina and Albina A encroaching above that mark we are having to redefine what a tiny home really is.  Both of these examples are under 600sf but have non-legal loft space of 300sf.  One could define a tiny home on square footage alone.  Part of the problem here is when a tiny home gets a modification that increases it's size past the cutoff point.  Does it then suddenly become a standard sized single family home?  We would like our classifications to make sense but also be flexible without being unruly.  So perhaps we increase our benchmark but it becomes a game of chasing one's tail.  At some point a tiny home may be around 1000sf.  Do we then bring all the related models up to the standard set on account of the largest revision?

In the meantime we have increased our tiny home definition to 700sf if only to accommodate our latest design.  The Durham A is based off of the standard Durham, but with an attached 10x12 addition.  This brings this little 1 bed 1 bath accessory dwelling up to 696sf.  Why do you think we upped our maximum size?  We liked the original of this little beast but were inspired to increase it after playing with some LEGO bricks.  In fact, the picture on set 5477 looks similar to what we ended up building.  Our drawn plans have a little more precision than the plastic brick model.

Speaking of which, if you would like to commission a LEGO model of any of our homes that you are building, contact us and we'll talk about details.

I Build House Plans

Well, not us specifically, but one of our house plans was recently purchased and is undergoing a bid process.  Samanns Construction is building the Lombard 1558-2 in Ambler, PA.  His website, http://www.203locustst.com is currently soliciting bids for every part of the construction process.  If you are able to conduct business in Ambler (north a bit of Philly), contact them to submit your bid.

Only two things disappoint us about this build.  The first is that they removed the bay windows, especially the inset bay in the dining room.  While we can understand the desire for an easy square build, it feels like the character is being removed.  Second, that they offer carpet in the basement as an upgrade.  This is almost always a sure-fire way to get mold unless you are meticulous about your specifications.  We bid you a sincere good luck.

Thanks for purchasing from Istockhouseplans and we look forward to seeing the final product!

Historic Fail

If you've seen Istockhouseplans' portfolio lately, you may have noticed a pattern.  We're pretty crazy about historic styles.  Large wood, texture, built-ins, house bling, etc. all play a part in the way we design.  But our design only covers part of the scenario.  We can design all we want, but the final product is left to the builder.  We can spec out materials and such but the fact is that the permitting jurisdiction only cares about structural and code issues.  As well they should.  Historic review boards will care about such matters.  In fact, we were recently privileged to sit in on and testify in front of a historic review board for a private commission we are working on.

While the historic review board was amenable to both historic-ish styles and the builder's pocketbook, we were a little disappointed that they didn't even discuss certain issues.  Some of these we think are crucial to distinguish between a true classic and a blatant reproduction.  While we mentioned some key issues a few years ago, we think that there are three that should always occur on a reproduction or historic remodel:

Windows.  Look at an old house.  Where are the windows located?  They are generally inside the wall.  Now look at most new homes and answer the same question?  The windows on the outside of the wall.  A little 2-3" nudge makes a huge difference.  So how do you install a new flange window inside the wall?  One way is to frame your openings 3" larger each direction and then install a 2x4 subframe inside the 2x6 frame.  The window then gets mounted to the subframe and floats inside the wall a few inches.  Cut down on all the extra wood by integrating the 2x4 subframe as part of the structural load path.  Another option is to purchase tip-in style retrofit windows.  Cost may be a factor in this case.

Siding.  Have you ever wondered why a substandard recladding of an old home looks so disappointing?  Think texture and relief.  First, old homes did not have one type of siding.  Two are minimum.  Even if both styles are lap and the difference is 4" vs. 8" reveal, it can make a house pop.  The biggest problem in our opinion is the relief of fiber cement lap siding.  How thick is the bottom edge of yesteryear's lap siding?  Darn near 1/2".  Now look at the specs of Hardi-plank.  How thick?  5/16", barely more than 1/4".  the stuff might as well be flat.  That tiny little edge looks puny, like trying to do 5/4x6" bargeboards.  Hey Mr. Hardie!  Have you ever considered putting a lip on the edge of that stuff to give it a stronger look?  If we ever get to build, we will not use that stuff.  Who cares if it lasts 100 years.  That's 100 years of puny looking disappointment.  "What will you use then, tough guy?"  What indeed.  Glad you asked.  Wood.  Wood lap siding with a 1/2"+ edge to it that makes the house look like it has been around forever.  Prime 6 sides and paint the visible sides.  Lots of work, yes, but the result is amazing and the durability just as good as Hardi.

Roofing.  It used to be (back when I was a boy!) that the roof color was complementary to the color scheme of the house.  Light grays, browns, even red, blue and green asphalt shingles gave interest to the color scheme below.  Now it seems that most new homes are similar to the Model T.  "Your roof can be any color you want, so long as it's black.  Because I bought 3000 squares and I have to get rid of it..."  Why are new roofs black anyway?  Is it because there's some aesthetic about a sharp contrast to one of the 3 shades of camel that new homes are colored?  We think it looks like a thick heavy black cap that smashes the house down and makes it look foreboding.  It also invites heat to be absorbed into the attic.  If you're building new historic or renovating, please don't use black.

If anybody out there can answer our concerns, we would love to hear.  Add a comment to this blog and set us straight.

I curse you... thinner!

As if taken by some inexplicable force, Istockhouseplans has become more and more obsessed with smaller and smaller homes.  Our latest release is sure to boggle the mind.

The Cascadia 1052 was contrived after looking at a typical 15' skinny house the wrong way.  The massing portion appeared to be only 10' wide and seemed reasonable.  "What the hey, let's see if it will work!"  It, um, did.  Sort of.  We made a 3 bedroom, 1.5 bathroom home in 1009sf and 10' wide.  It's kind of like a shotgun house except it's 2 stories.  So it's more like a single barrel shotgun with a massive sniper scope.  Give it a look and tell us what you think.  If the reaction is generally positive, maybe we'll try another iteration.  If the consensus involves torches and pitchforks, we'll drop the price.  If there's no reaction whatsoever, we'll go out for beers.

Speaking of which, the first person to build these plans gets a free 6-pack, on us.