The
Ideal Home
DESIGNING FOR
COMFORT, DURABILITY,
EFFICIENCY AND HIGH QUALITY
by
Randy L. Martin
The
Ideal Home is a home designed for comfort, quality, and efficiency. What does it
take to build the Ideal Home? Most builders today feel that if they use quality
materials and good workmanship, a quality home will result. If that is the case,
why do we have so many callback problems today? We have better paint, better
insulation, better windows, than ever before, but we have more problems today
than ever before. Why is that?
The problem is not good
workmanship or materials, the problem is understanding. Houses built 30-50 years
ago were cold and drafty, while houses today are considered quite comfortable,
but frequently experience durability problems. We have sacrificed durability for
comfort.
There are three important
changes in the last fifty years: the introduction of thermal insulation, the
development of tighter building envelopes, and the invention of forced air
heating and cooling systems. Each of these changes has made our homes more
comfortable, but also less durable. Fortunately, it doesn't have to be this way.
We can build homes that are comfortable, durable and energy efficient.
You can have a comfortable
home that is also efficient and durable. By understanding how the components of
a house interact and using the proper construction techniques, you can build a
house that is comfortable, efficient, and will last 100 years. Follow these
simple construction guidelines and you'll have a house that you can be proud of.
KEYS TO THE IDEAL
HOME
The following are some of
the key design elements for the Ideal Home:
Site Selection
(not always an option, but if the option is there, consider these elements):
- Select a site with the
back to the S, SE or SW.
- Shelter site from the NW
winds and open to the S/SW summer breezes.
- Make sure site is well
drained.
House Layout
- Locate the most actively
used areas (family room and kitchen) where they will benefit from
daylighting.
- Concentrate windows on
the south side to capture solar gains in the winter.
- Minimize east and west
windows to lower cooling costs.
- Use light colored walls,
floors, and ceilings to maximize the daylighting effect.
- Locate the garage on the
NW corner of the house to buffer against the winter winds.
- Locate fireplaces on
interior walls, not exterior.
Building Envelope
- Seal all joints in the
building envelope with caulk or a gasket.
- Seal all penetrations
into the building envelope.
- Install a vapor
diffusion retarder on all inside walls and ceilings.
HVAC Systems
- Install a controlled
ventilation system. Building envelopes must be "built tight, and
ventilated right".
- Use a power vented or
sealed combustion unit if you are using natural gas or propane as your
heating and/or water heating fuel source.
- Locate furnaces and/or
air handlers within conditioned space.
- Use fully ducted
returns, not panned floor joists or other building cavities.
Appliances
- Install a kitchen range
hood directly ducted to the outside, if a gas range is going to be used.
- Use outside air for
combustion for fireplaces and/or wood stoves.
- Consider energy
efficiency when selecting refrigerators, freezers, washers, dryers, and
light fixtures.
- Directly vent dryers to
the outside.
Commissioning
(ensuring proper functioning of the home and educating the occupants)
- Test the building
envelope for air leakage with a blower door.
- Test the ducts for
leakage.
- Test the venting of
carbon monoxide from combustion appliances under all operating conditions.
- Test the home for radon
gas.
- Educate occupants in the
correct operation, maintenance, and housekeeping requirements of the home.
These are the keys to the
Ideal Home. It is highly recommended that you obtain a copy of the Energy
Efficient Building Association's (EEBA) Builder's Guide for an in-depth look at
how to build comfortable, efficient, quality homes that will stand the test of
time. You can obtain a copy of the EEBA Builder's Guide from EEBA, www.eeba.org.
RECOMMENDED
ENERGY EFFICIENCY FEATURES
Below is a table that gives
you the recommended energy features to achieve the Ideal Home status. The table
also includes features that will help you achieve even higher levels of
efficiency. These are just recommended starting levels. Your house may not
achieve these ratings due to orientation or home configuration. You need to
submit your plans with your specific energy features to Energy Rated Homes of
Iowa for a preliminary energy rating. The final rating also depends on an actual
test of the air tightness of the home. If you have the recommended insulation
levels and equipment efficiencies, but have not paid attention to air sealing,
you may not achieve the desired level of efficiency.
Building Section
|
Ideal
Home
****+
|
Ideal
Home
*****
|
Ideal
Home *****+
|
Foundation*
|
R-10
|
R-13
|
R-19
|
Rim Joist*
|
R-20
|
R-20
|
R-20
|
Side Walls*
|
R-15
|
R-22
|
R-25
|
Windows
|
R-3
|
R-3.5
|
R-4.7
|
Doors*
|
R-5
|
R-5
|
R-5
|
Ceiling*
|
R-40
|
R-40
|
R-50
|
Furnace
properly
sized & sealed combustion or power vented |
90% AFUE
|
90% AFUE
|
95% AFUE
|
Air
Conditioner
properly
sized |
12.0 SEER
|
12.0 SEER
|
14.0 SEER
|
Controlled
Ventilation System
|
Yes
|
Yes
|
Yes
|
Duct Work
Joints
sealed with mastic & insulated in unconditioned |
Yes
|
Yes
|
Yes
|
Water
Heater
|
.59EF
|
.59EF
|
.96EF
|
Natural Air
Leakage Rate
|
.35 NACH
|
.15 NACH
|
.05 NACH
|
HERS Rating
Point
Score |
HHHH+
86.0
|
HHHHH
90.0
|
HHHHH+
95.0
|
* Insulation levels listed
are the composite r-value of the entire assembly.
This is only a starting
place. You can achieve the Ideal Home level of efficiency in any number of ways.
We encourage you to experiment with different approaches to determine which
construction approach works best for you.
The following wall section
shows one way to build to the Ideal Home level of efficiency. This wall section
is meant only to serve as a guide if you are not sure where to start.. You are
free to come up with whatever approach works best for you to achieve the Ideal
Home status.
IDEAL HOME WALL
SECTION
ACHIEVING THE AIR
TIGHT HOUSE
The secret of a
comfortable, efficient, quality Ideal Home is building it air tight, with
controlled ventilation.. You might ask, why build it tight if you are going to
have to put in a special controlled ventilation system? Why not just allow the
building to ventilate itself? The big reason is MOISTURE. If you allow moisture
to get into the walls and the attic (where it is cold in the winter), you will
get condensation, which leads to mold and mildew and eventual rotting of the
structure.
The solution: pay special
attention to making the home as tight as possible and install a controlled
ventilation system. This will allow the homeowner to exhaust old and stale
indoor air as well as control of the amount of fresh air coming into the home.
Commercial buildings have been doing this for years.
Here's a list of locations
where you need to make sure the holes and cracks are sealed:
- basement floor/wall
joint
- sill plate
- rim joist (top &
bottom)
- wall/floor joint
- around doors &
windows
- electric outlets &
switches
- wire penetrations into
attic
- light fixtures
- utility service
entrances
- around plumbing stacks
& chimneys
- attic hatch
- around vents
SUMMARY
In conclusion, build the
home smart (tight and well insulated, paying attention to detail) and it will be
comfortable, efficient, and durable. A well-built, high quality home that will
last far into the next century.
|