Blower Door Test at NHND to the Pond

This week the HERS rater conducted the blower door test on the New House Next Door to the Pond. This tests the air-tightness of the building envelope and measures the number of air changes per hour and is now required for all new construction in NYS. The NHND to the Pond scored a respectable 49 HERS Index rating and 1350cfm50 during the test.

Older homes, built before building wraps or board sheathing or wall board or spray foam insulation can be very porous in terms of outside, un-conditioned air getting in and inside conditioned (heated or cooled) air escaping out. You might think of this as a "drafty" or "leaky" building. And that was the "norm" for many years in construction.

Nowadays we try to decrease our usage of energy and minimize our impact on the environment (or minimize our financial costs - different impetus for different folks, for sure...) and the newest IECC (International Energy Conservation Code) has forced all but historic buildings to meet more stringent insulation and air-tightness standards so they will use less energy to be heated and cooled.

I've always designed my projects to be "green" and while I haven't sought certification by LEED (Leadership in Energy & Environmental Design) or Energy Star, I have always detailed my buildings to be as environmentally friendly as construction can be, sometimes teaching the contractor or inspector about construction details I've learned about in building science classes.  Being "green" usually means creating the best "building envelope" (line separating inside from outside) we can to keep the building's energy usage down to a minimum. (Rather than all the myriad of other "green" ideas, like Forest Stewardship Certified lumber, or reusing materials from deconstructed buildings, or considering the embodied energy of materials/products we build with, or specifying low water-usage fixtures or low-wattage lighting/appliances, or thinking about other sustainable materials, like wool or cotton insulation batting, etc.)

CI layer visible just outside of framing

Recently that's included continuous insulation.  And often the use of spray foam insulation at key trick spots, like the rim joist. Slab edge insulation and the best windows you can afford all help, along with a lot of insulation in the roof/attic. Click here to see an older post about insulation: 2014/02/insulation-phase-1

HRV (on the right) takes heat out of the air before expelling it out of building

When you start getting a super tight building envelope, you need to introduce mechanical ventilation to ensure healthy indoor air. It may seem counter-intuitive (why not just let the building breath???) but the science shows that tight buildings with (continuous running, even) mechanical ventilation systems use less energy. Click here to read an older post about Heat Recovery Ventilators (HRVs) http://cwb-architect.blogspot.com/2014/06/air.html

Insulated Cellar Access

Whoops! Not quite finished yet!

During the test and other check-point inspections potential problem areas were discovered and some were remediated.  The cellar door access was basically a hole in the building envelope, so an insulated interior stud wall was constructed for the insulated, weather-striped door to be installed into. Also it was found that the continuous insulation and finish specified under the cantilevered floor areas was never installed. When that is complete, our numbers might be even better!

Here is the bright & colorful HERS Index graphic:

NHND to the Pond- Interior Finishing

Interior Doors and Trim Installed, Shelving for Closets, Wall Paint

At the New House Next Door to the Pond the interior finishes are just about done. The staircase is built and installed, all hardwood and tile floors are installed and finished, walls and ceilings are painted, window and door trim is installed and painted or stained, and cabinetry and built-ins are in. Last will be plumbing and light fixtures - then the new homeowners can move in!

Here are some photos:

Cabinets for Built in Desk- in Office Room looking at Pond

Tile & Bead Board Walls and Cabinetry in Bathroom

Built-in Window Seat and Bookcases in Bedroom

Staircase (and efficient HVAC unit)

Kitchen Cabinetry and Counter Tops

Tile Foor, High Wainscott Boards, Built-in Bench, and Cubbies in Mud Room Entry

Living Room - Stone at Wood Stove

Open Railing with Craftsman-Style Newel Posts

Site-Built Doors to Access Storage

Wood Ceiling in Screened/Sun Porch

Bead Board Ceiling and Final Trim at Posts & Beams in Back Yard- Frame View to Pond

3-D Models Show Clients their Design

As an architect I use Autocad LT for my drafting and a good old black Sharpie on trace paper for some of my early schematic design work, but I also like to use Google Sketch Up to create quick 3-D models of proposed designs for buildings. It's an easy program to learn, and without too much time or effort one can create a massing model and fly around it with a camera showing what a new building or addition to a building might look like.

3 dimensional models be extremely helpful for those clients who are not adept at reading the 2-D elevations that we architects draw and submit to building departments and contractors. Elevations show a (distorted from real life) flat-on view of one side of a building. It's a view, that depending on the site, a human might never really even see - a perspective view is much more realistic- and without labels, it may be unclear what each line represents.

First take a look at the drawing of the front elevation above. It's flat and it may be difficult to completely understand what all the lines around that boxed out window on the right really mean.

 Below is the small "video" I was able to easily create and save in Sketch Up which flies around my 3-D building model of this cottage, showing all sides and how the building sits on the sloped site.  The building model here is still very basic, like the line drawing above, yet because it's no longer representing only two dimensions, it is able to convey much more.

Below are final portfolio photos of the same project. (Hopefully this looks like you expected it to look, having seen the drawing and model of the design, even though the sketch was rough and not fully detailed) I think you'll agree that Sketch Up (or any 3-D model- even a physical one built from board and glue) is an advantageous tool for architects to use to communicate their ideas to clients.

Front of Building after Completion

Back of Building after Completion

Here is another animation (short video) of another model, just for fun. This model has some more detailing as far as color, materials and textures, so it looks  more realistic. This is actually the house that you see beyond and on the left in the photo above. (We ended up adding a balcony above the covered porch on the left/west of the house, which you see in the photo, but not the drawings.)

Here are the 2-D elevation drawings (front view and partial side view) showing the same project. In this example, we were exploring connecting a gable-end porch to wrap around the corner and offer weather protection over the front door. As I think you can see, the 3 dimension models are much better at showing what the changes look like than the 2 dimensional drawings.

New House Next Door to the Pond Update

Entry Drive Passes PV Solar Panels

It's winter and the New House Next Door to the Pond, while being placed back from the road, is just visible through the leafless trees. The dark color selected for the siding helps the home blend into it's wooded surroundings.

Craftsman Style Front Porch with double post on paneled base

 Entering the long (muddy and snowy) driveway toward the house, one is greeted with four solar panel masts oriented to soak up the sun and create all the home's electricity. This on-site, clean power generation, in conjunction with the super-tight, well-insulated building envelope and the efficient air-source heat pump HVAC/HRV makes this home come close to zero net energy use.

The exterior siding and roofing is completely installed, albeit not completely painted. (most of the material is Hardi shingle or panel and came factory painted in "Deep Ocean" and "Cobblestone") Custom details like shingled gable walls, contrasting wide trim at windows and other elements, brackets supporting roof overhangs, and double porch posts sharing a solid base contribute to the "Craftsman Style" feeling of the exterior.

Brackets (to be painted) contribute to "Craftsman" Style Exterior

The west side of the home is where the special "exterior living room" is located. This is more than just a screened porch. Three sides of  the room can change seasonally from screened panels to glass panels, extending the usefulness of the space in our climate. The porch faces the pond and the west and is accessed through french doors from the living room.

Other interior finish work (the slowest part of construction) has be done also: the sheet-rocking, taping and painting of ceilings and walls, and the installation of the hardwood floors. Next will be interior window trim/sills, wood wainscotting and wood ceilings, construction of built-in bench and window seat and bookcase/stair/railing, and installation of kitchen and bathroom cabinets and fixtures!

Floating platform is Upper Stair Landing (window half obscured by plywood)

Future Window Seat

Long view - exposed beam supports second floor

Future Built-in corner Bench for Eating Nook

Exterior siding and roofing is complete

South Elevation - see ice-covered pond down hill on left & plywood covering garage door opening on right

Spray Foam and Rigid Insulation

The New House Next Door to the Pond got an insulation and air sealing inspection today. Next up will be a blower door test, to get some hard data on how well it was installed and if there are any holes that need filling prior to finishing the construction. In addition, an infrared camera can capture images showing where there is heat loss- and if we did that today, we would see a big hole around the cellar access door that needs to be addressed. (Other very notorious holes in building envelope are fireplace chimneys and skylights, neither of which were included in this project by design)

Spray foam in cavities, box beam; Rigid XPS at headers

In this super-tight building envelope design, all walls and roof surfaces have continuous rigid foam insulation, and the wood-framed walls and roof also have cavity insulation. The continuous insulation (CI) material is Extruded Polystyrene (XPS) and has an R-value of about 5 per inch. There is R-5 on wood walls, R-10 on basement walls, and R-20 on all roofs. The cavity insulation, for the most part, is open-cell spray foam with an R-value of about 3.6/in and is located between all exterior 2x4 wood walls studs and between 2x roof rafters and wood roof trusses. Closed cell spray foam was used in one location (the main floor box beam) and that has an R-value of about 6.5/in.

Recessed lights placed in soffits, not in building envelope

This design exceeds minimum R-value requirements of the "Prescriptive Path" of the Energy Conservation Construction Code, but air sealing is probably more important than R-value, really, so it's the high-tech barriers with taped seams and that CI that really make this system excel in the most economical way. Without CI, that infrared camera would show heat transfer at each wall stud and roof rafter; this is "thermal bridging"- the wood is a bridge connecting inside and outside. That won't be the case with the 1"-2" of CI on the walls and 4" CI on the roof.

If only cavity insulation is used, there would be thermal bridges/no insulation at each wall stud

I am very pleased about this project and the team that is working to create a house "built as all houses should be built", as the independent energy inspector stated today. (speaking from an Energy Code Compliance standpoint)

Raised-Heel Scissor truss allows for lots of insulation