Elements of a Healthy House
by David Cheyne
UPdate Fall 1995

     This article is designed to give the reader a general overview of what materials and practices go into a Healthy House.  This list is not all inclusive, but it concentrates on what is widely available in Nova Scotia.  Although it is important to look at both the inside and outside of houses, I will focus on the elements of the inside, the living envelope.  One caveat when using this as a guide is that you must always test the materials to see if you (or your co-habiters) are sensitive to them BEFORE you install them.

     When considering the costs and benefits of renovating an existing house to become a healthier house, you should first consider the materials used on the largest surface areas (i.e. floors, walls and ceilings).  Also, on the priority list are safeguarding the bedrooms, where people spend one third of their lives.

     The following sections are explanations of healthier building material options for the major parts of the house.

Flooring
     The best materials for flooring are hardwood (pre-finished or finished on-site) and ceramic tile (set and grouted with mortar).  Pre-finished hardwood usually has a more durable finish than site finished and is usually more off-gassed.  Site finished hardwood, however, results in a smooth surface whereas pre-finished hardwood leaves small grooves at the joints which can harbor dust or can trap spills which will eventually turn into a mould problem.  Also, by having gaps, fumes from the unfinished part of the wood can be released and will be a problem if you are sensitive to it.  The Nova Scotia R2000 Program encourages the use of hardwood and ceramic tiles for flooring materials.

     Carpet holds dust, dust mites, mould and bacteria.  It is also difficult to clean and in most cases off gasses chemical fumes (the infamous “new carpet” smell).  The CBS program Street Stories included a segment about the hazards of carpets about a year or so ago.  It included an experiment performed by a laboratory which tested the reactions of mice when air was blown over new carpet from which the mice had to breathe.  Within 24 hours, all of the mice were dead or severly crippled.  The US Environmental Protection Agency removed carpets from all of its offices, but stopped short of announcing it as a danger to human health.

     Cushion flooring off gasses VOC’s and is not recommended.

Walls & Ceilings
     The best paint to use is the one you don’t react to.  Some of the safer paints are VOC (Volatile Organic Compounds) Free.  When painting, you should take care to do one room at a time and remove any furniture or other items which can “absorb” any paint fumes (VOC-Free paints included).

     Wallpaper is generally not very good because of the off-gassing of chemicals found on the surface.  Water-based stenciling is very acceptable for decorating.

Windows
    CMHC research has shown that Low E windows are good for energy efficiency, but there are concerns that they filter out beneficial natural light.  The two most popular framing materials for windows are solid vinyl and wood (usually pine, which off-gasses turpines).  Solid vinyl windows are maintenance free, whereas wood windows require maintenance (i.e. painting).  Selection of either of these will depend on your sensitivity.  One thing to consider is that windows placed on the north side of the house tend to off-gas less than windows placed on the south side.  So, you wouldn’t want to place windows you are sensitive to on the south side, but you may get away with installing them on the north side.

Lights
     Numerous studies have shown that natural light is necessary for human health.  Try to design your house with as much passive solar exposure as possible.  Also, use of full spectrum lighting is favorable over standard lights.  It is now becoming more widely available.

Kitchen
     Cabinets made of solid hardwood are healthier over particleboard because it off-gasses formaldehyde.  Alternatively, if particleboard can’t be avoided, due to cost or other factors, all unfinished sides should be sealed with a water-based sealer or aluminum foil attached by aluminum tape.

     Healthier countertop materials include Corian (a solid polymer which can have any scratches sanded off), granite or ceramic tile on exterior grade plywood (exposed plywood would have to be sealed).

     Shelving material recommended for use includes solid hardwood, exterior grade plywood encased by arborite or epoxy-coated wire (Lee Rowan is a popular brand of this type of shelf).

     The stove should be vented directly outdoors.
 

Basements
     The ideal Healthy Home basement is no basement.  The deeper into the ground one goes with basements results in higher potential for problems.

     Mould is major problem here (see CMHC Mould article), as well as radon, which is a radioactive gas emitted from the ground.  Parts of Nova Scotia are high risks areas for radon, including parts of Halifax.

     Consult the Department of Energy, Mines and Resources for more information.  You can also have your basement tested for radon (some of the companies advertising in this publication offer radon testing).

     If you wish to go with a basement, make sure it is well sealed at all the joints and around plumbing drains (no part of the ground should be exposed).  A proper vapor barrier should be installed below the concrete floor.  Also, make sure there is adequate ventilation to exhaust the expected moist air or else you will run into a mould problem which can be difficult to get completely rid of.
 

Heating Systems
     Selecting healthier heating systems is difficult because each has its own problems depending on your sensitivities and how they are installed.  Use of fossil-fueled furnaces/stoves have the potential for releasing hazardous gases into the living area (carbon monoxide is one).  If you already have a furnace, consider testing the air around it for carbon monoxide on a regular basis.

     Carbon monoxide is an invisible, ordorless gas which can kill when it is present above certain levels and can cause flu-like symptoms over extended periods due to continued low level exposure.  As furnaces age (or furnaces without adequate air supply), they tend to burn less effectively and are more of a risk to emit noxious gases. 

     Electric baseboard can act as a dust collector and burns dust and dust mites when the heat comes on.

     Ideally, you want a house that does not require a chimney (i.e. no fireplace, furnace or wood stove).

Ventilation
    Opening windows will let in fresh air, but it doesn’t get to all areas of the house and heat is lost as well.  The best solution is to install a Heat Recovery Ventilator (HRV).  This will provide ventilation to all areas of the house (to which it is directed) and recovers a large portion of the heat from the out-going air.

     Contrary to popular belief, ventilation is not the panacea for air quality problems.  You must first eliminate as many offending materials as possible, and then the remainder you encapsulate (seal) or ventilate.

Miscellaneous
     Some of the biggest offenders with regards to air quality are not building materials, but in fact are cleaning products and personal care products.

     Consider switching to unscented products.  A lot of hospitals, schools, office buildings, churches are initiating Scent-Free policies (see Scent-Free list in this issue).  This is in response to the growing evidence that scented products adversely affect air quality, much in the way second-hand smoke does (i.e. both involve chemical emissions). 

     Any paint cans or other potentially harmful items should not be stored in the living envelope (this includes basements) as they have the potential for leaking fumes, even if they are covered.

     There is limited amount of space to cover a topic such as this, so if you wish to get more details, consider ordering some of the literature provided by the CMHC (see advertised list).

     Also, Robin and Audrey Barrett, of Healthy Homes Consulting, teach courses on this subject and are highly recommended (coming from a person who has taken it).