House features

Back again!  So here are some of the features of the house.

   The house is small, 32' x 24' footprint that equates to 1536 sf of conditioned space.  We kept the footprint small for several reasons.  First a larger house means we have to buy more stuff to fill it up thus reducing the Funstuff Funds.  We'd rather go play than buy another sofa.  Secondly, if we keep it small we can add other features to the house, LEED certification for instance.  Lastly, LEED rewards smaller homes.  Not suprisingly larger homes consume more resources, not just building materials but also heating and cooling.  They award smaller designs through the Home Size Adjuster (HSA).

   Based on informal studies and published data, within the context of LEED, a 100% increase in home size equates to an increase in annual energy usage of 15% - 50%, depending on the region.  Also the same increase equates to an increase in materials usage of 40% - 90% depending on the design.  So smaller homes can earn extra points towards certification based on the number of bedrooms and square footage.  So the SCF house will 5 points based on the square footage and bedrroms.

   We've tried to keep as many penetrations out of the exterior walls as possible.  You'll notice that the only fixture mounted on an exterior wall is the sink in the Master bath.  Believe me we tried every possible combination to get it off the wall.  The reason we kept out of the exterior walls is that every penetration is a potential air leak.  Air moving inside the thermal barrier sets up all kinds of potential problems with moisture in the walls as well as reducing the efficiency of the walls.

   "Smart Framing" will also be utilized in the construction.  Smart framing incorporates techniques such as aligning roof trusses and wall studs so that the trusses bear directly on the studs.  This eliminates the need for a second top plate on the wall.  Also no headers in non-load bearing walls, sizing headers to the exact size needed, studs and rafters spaced greater than 16" on center and no trimmer studs at window and door openings.  All of this amounts to significant reductions in the amount of wood needed top build the house.  Also less wood in the walls means more room for insulation.

 Well lunch is over, back to the grind.  More to follow.

Design Review

  Alright, alright so it's been a few days, ok weeks since my last post.  My apologies.  What with trying to get hoop houses built, researching and tracking down products, things have been pretty hectic.  The good part is now I have some images to share of our proposed floor plan and a couple of elevations.

  We finished up our design charrette last week with Dave from Lindhout, Tom Boyle, John Boylan of Lakeside Services (HVAC), Tom and Shannon Rau, Joannee and I and our Green Rater, Alex.  We had a really good meeting lots of good discussion about mechanical systems and photovoltaics.  The house has undergone a few iterations since the initial charrette and as a result we hope to pick up 5 more points toward our LEED certification.  But I won't get into the geeky stuff tonight.  I would like to talk the house and maybe some about our product selections so far.

You can see we retained the small footprint of the house, it took a few heart to heart discussions but with some design help from Joannee, Dave and Piet were able to draw out a really fun floorplan on the first floor without expanding the size of the house.  This is important to us because more space means having to spend more money to fill it up, heat it, cool it and clean it 

1. Tulikivi masonry heater is the centerpiece here, literally.  Locating the heater in a central location and with very few walls will allow us to use this as the primary heat source in the winter.  This is a soapstone behemoth weighing in at over 5000 lbs.  The soapstone absorbs the heat from the fire and slowly radiates the heat outward over time.  A 1 1/2 hour burn twice a day will heat the house for about 24 - 30 hours.  Possibly longer with the R-35 walls.
2. Reclaimed wood flooring throughout the house upstairs and down.  We are looking at maple or possibly locust.
3. Recycled brick in the mudroom coming from the garage.  The mudroom was originally going to be the space between the garage and main house.  Thanks to a little sleight of hand from Dave we were able to increase the size of the room in the house.  The original mudroom now becomes a breezeway and a home for the grill.  Also becasue the garage is detached from the house, this improves the indoor air quality and scores 3 points for LEED.  Durability is also a LEED consideration and we have developed a project specific durability checklist.
4. The kitchen is on the south side of the house.  In order for the house to benefit from solar orientation LEED requires 40% of the total glazing area to be on the South side.  A challenge when you have a small house, a fairly steep roof and countertops to work around!  Again, Dave sneaks in the round window in the upstairs bedroom to eek us over the line. We are considering two manufacturers Accurate Dorwin made in Canada and Serious Windows, made in California,  Both exceed Energy Star ratings by almost double.
5. All appliances in the house will be Energy Star rated.  Hopefully we will be able to reduce our electrical load in the house enough to make solar power feasible.

Ok it's late, I'll add more tomorrow.  Oh wait, I said that last month.

LEED Design Charrette


Well we got through our design charrette today.  For those of you who may be unfamiliar with this term, charrette comes from the French for a wagon or carriage.  Back in the day, French architectural students would cram into the carriage and would work madly to finish their sketches before arriving at class.  Today a design charrette is a day of brainstorming and throwing ideas out on the table for discussion.  For the purposes of LEED it the day when the team considers all of the available points that can be pursued, and they rate which points are achievable, not achievable and those maybe points that are worthy of further consideration.


Integrated Design
The key to making this work is having as many people from the project team present as is possible.  Today we had Dave from Lindhout Architect's present, as well as Tom and Joannée from Stone Coop, myself as Owner's rep, Tom Boyle our builder, Mike from Alliance for Environmental Sustainability, Alex our Green Rater, Scott our HERS rater/energy modeler, John Boylan from Lakeside Heating & Cooling and Brent Deline our framing  contractor.  Everybody had a chance to comment on the credits and discuss possible strategies.

The idea in getting everyone on board early is to have the team influence the design early on rather than reacting to design on the jobsite.  Everyone has a clear understanding of the goals early on and they have had an opportunity to discuss how all of the parts and pieces go together.  Rather than the old fashioned way, getting to the jobsite and having several people scratching their heads trying to figure out what the designers were trying to accomplish.


The Checklist
I don't have a final copy of the checklist yet but I will post as soon as I do.  We were shooting for a number in the 70's which would put us solidly in the Gold category.  We ended up at 84 pts only 6 points away from Platinum.  We have a fair number of points in the maybe column that we can pull on for the other 6.


Here's a short list of some of the major strategies we are attempting:

1. Smart Framing - We'll be using 2x6 stud walls spaced 24" on center.  This will allow fewer studs in the wall which increases the area for insulation and uses less wood.  Also part of this framing method is to not double up on studs around windows and doors (trimmer studs) and to properly size headers for the anticipated load and on non-load bearing walls you don't use a header.
2. Outsulation v. Insulation - We will be using a 1/2" structural insulated sheathing on the exterior walls, no osb, with and additional 2" of R-10 rigid foam insulation over that.  We're shooting for an R-30, R-35 wall.  All seams will be taped or glued to create a really tight air barrier.  The problem with wood on the exterior of the structure is that when the house is warm in the winter, the wood sheathing is warm on one side and cold on the other.  This creates a place for water vapor to collect.  With a long enough summer and good ventilation the sheathing will dry. But enough cycles of this creates a potential problem.  We're still discussing the wall cavity insulation.
3. Roof Insulation - The roof will consist of a foam insulation sealing the truss chords and the ceiling drywall.  Then we will blow in insulation over that.  We are shooting for approximately R50 in the roof.
4. Heating/Cooling - Ductless heat pump system.  Very high efficiency, SEER 18, and no duct work.  There is a condensor unit located on the exterior of the house and then 3 - 4 fan units inside.  A Tulikivi masonry heater.  Essentially a 3,000 lb soapstone fireplace that, with 2 hours of burn time, will radiate heat for 24 hours.

These are just some of the items we are including in the house.  We will also have re-claimed wood flooring, low or no VOC paints, sealants and adhesives, buying materials with 500 miles of the jobsite just to name a few.


I'll get some more up this week end.  I'll try and get more photos up as well.

                                    
Joannée as architect.