Tom Konrad is an Analyst at Alternative Energy Stocks, where he writes about investing in renewable energy and energy efficiency companies.  This article is a guest post for Jetson Green.

As a Jetson Green reader, you probably love efficient, modern homes, and probably dream of building your own one day.  But that may not be much help if the home you are looking for today is your next rental, or you need to live in an area where land is not available to build your own place.  You may find yourself looking at existing homes instead. (Existing homes account for 85% of the homes sold each year, and more of the rentals).

At the 2007 Energy Star Summit, which I attended December 3rd and 4th, I sat in on multiple workshops geared towards Energy Auditors, the people who verify the performance of your home and recommend cost-effective improvements.  After three of these workshops, I decided I will never buy a house that is not a new Energy Star, Built Green, or LEED certified one, without first having a home energy audit by a professional auditor, no matter what the price.  Each of the above ratings/certifications included some form of energy and safety audit.

It's true that you can buy an old house and upgrade its energy efficiency and safety, but such upgrades can be extremely difficult.  Upgrading energy efficiency can seldom be done as inexpensively as building a home right in the first place.  An Energy Auditor will help you understand what the true cost of living in the home will be, and what it will cost to make any necessary upgrades.  In a down housing market, a Home Energy Rating System (HERS) report will provide a basis to ask the seller for allowances to upgrade the house. 

Energy Efficiency is not the most important reason to get an energy audit.  An energy audit may seem similar to a home inspection, but most home inspectors are only concerned with a house being up to code.  An Energy Audit is about home comfort, safety, and ongoing energy costs.  The home safely piece is crucial.  It's one thing to be uncomfortable, but leaky ducts can lead to depressurization in the home which may draw in toxins into the living areas.

However, energy audits typically cost between $200-$500.  If you are looking at several places to live, you'll want to narrow down your choices to one or two before calling in a professional.   The following list can serve as a guide to problems you may be able to spot yourself, and avoid spending unnecessary time or money looking at a home that will eventually turn out to need many tens of thousands of dollars of work.

Features to Look For:

  • Proper orientation.  Look for a home that has its longest side facing South, and does not have tall buildings or evergreen trees on that side.  Avoid houses with excessive glass on the East and especially West sides, unless trees or other buildings block the summer morning or afternoon sun.  Trees or other obstructions to the Northwest and Northeast are also good for keeping a house cool on long summer days.
  • Ducting sized for each room.  If the various ducts coming off the furnace are of different sizes, this is a sign that some thought was given to how much air each room would need.
  • Radiant floor heat, when provided by running hot water through pipes under the floor, is a feature to look for in old homes, because it is much more reliable, and less prone to causing ventilation problems.
  • Active ventilations systems to refresh the air inside the home.
  • Closed combustion appliances and fireplaces.
  • High efficiency furnace, air conditioning, and water heating.
  • Old utility bills. The Energy Star website has a Home Energy Yardstick that can help you understand how the home is performing.  If the owner is unwilling to provide you with their utility bills, that seems like a warning sign to me.  If they don't keep them, they should be able to obtain them from their utility, or give you permission to get them yourself.

Features Which Can Lead to Ventilation Problems or Poor Insulation:

  • Attached garages are notoriously difficult to seal off from the rest of the house, and carbon monoxide and other fumes which many automobiles emit when stopped often gets sucked into the living space.  It's difficult to avoid attached garages in many areas, so look for homes where the house does not completely surround the garage, but only has a single common wall.
  • Cantilevered alcoves and rooms.  Cantilevered spaces (where a higher floor sticks out with an overhang outside) are difficult to insulate and seal properly during home construction, so chances are, the original builder didn't.  I once rented a house where the can lights that came down from a cantilevered space above the front door.  Air was able to flow through the can light fixtures above the door, through the first floor ceiling, and directly into the kitchen through the can lights in that room.  The floor of the second storey was essentially open to the outside air.
  • Ventilation ducts all the same size.  This is unfortunately typical in older homes, and usually results in some rooms getting all the conditioned air, while other rooms get hardly any at all.
  • Ventilation ducts in unconditioned space.  These ducts leak heat or cold to the outside, and can bring in unhealthy air (has an exterminator ever sprayed under the house?) into living areas.  This can usually be fixed by sealing and the space around the ducts, bringing it inside the building envelope.
  • Downdraft and other high-volume kitchen vents can aggravate other ventilation problems by significantly lowering the pressure in the home and sucking in outside air wherever it can get in.
  • Unvented fireplaces and kitchen or bathroom fans.  Try to check to see that every fan or fireplace has a corresponding opening on the outside of the building.  In older homes, kitchen fans were often vented back into the building, and bathroom fans vented directly into the attic, where the moisture damages the insulation.
  • Masonry fireplaces in homes built mostly of wood.  Because wood shifts relative to brick or stone with changes in moisture content, it is extremely difficult to get proper seals around such fireplaces.  In general, junctions between different types of building materials should be viewed with suspicion.

Signs of Problems:

  • Water damage around window sills and ledges.  This is a sign of condensation in the winter, and while it is often not a result of leaky windows, it is often a sign of a whole host of ventilation problems.  Stains at the bo ttom of inside doors which are normally closed is another warning sign of ventilation problems.
  • Low pressure in combustion zone.  Close the door to the basement/utility room with the fan running.  If you can feel air being sucked in under the door, the air ducts are probably leaky.  Low pressure in the combustion zone can lead to a back-draft in passively ventilated furnaces or water heaters, bringing carbon monoxide and other combustion products into the home.
  • Corrosion around outside vents.  Don't ignore obvious warning signs.  If vents are corroded, something was not working right at some time, and may not have been fixed.
  • Musty odors. People living in a home may become acclimated to the odors of the home itself.  Pay attention to what your nose is telling you about possible mold and mildew, which may be a sign of wood rot or structural damage.
  • Hot or cold rooms.  This may be hard to detect yourself, but if you notice large temperature differentials between rooms, it should probably not be ignored.
  • Cold floors in winter.  Especially over a crawl space or in a cantilevered room, check to see if the floor is excessively cold to the touch.
  • Excessive ice dams and icicles in winter.  Heat escaping into the attic can melt snow on the roof while it is still cold enough outside for the water to refreeze as it flows off the roof edge.

Even if you're renting, you want to live in a comfortable, healthy, and affordable home, and knowing what to look for will be the first step to getting it.  If you're buying, you don't want to acquire someone else's problem.  If you get an energy audit for the home you are buying, it may also tell you what you need to do to qualify for a lower rate Energy Efficient Mortgage, or borrow a few thousand more dollars to make the necessary home improvements.