Healthy Homes Series #1 – Age and Foundations

Liz Bassett Sustainability

-Mikala Dind

In this six-part series, Narara Ecovillage member Mikala Dind shares her knowledge about what makes houses healthy or unhealthy. While this article is about existing homes, the information will definitely assist anyone seeking to build a home.


The age of a house can give clues to potential hazards.  For instance, homes built:

  • before 1970 may have lead paint
  • before 1987 may contain asbestos

In contrast, homes built recently are likely to contain multiple items that may off-gas for up to several years.

Older Homes


You can get a lead test kit from hardware stores which will give immediate results, so you can find out if the paint you are about to sand back on the window frames contains lead.  Don’t forget that if your home does have lead paint, there is a very high likelihood that your household dust (including in your carpet) and/or soil will also be contaminated with lead.  This is particularly important when there are small children in the home whose breathing space is close to the ground (and who put everything they find into their mouth).  

Also, if you are growing vegetables at home it is worth having the soil tested for lead contamination, especially if there is lead paint or you live by a main road or industrial area. One way to test your soil is Macquarie University’s VegeSafe Program, which is free (they do ask for a donation). Simply collect soil samples following their instructions and mail them to Vegesafe. More info here 

Image: Vegesafe

Other areas around the home that may contain lead are solder on water piping connections and flashing.  The Australian Government has a helpful booklet about lead and how to work with it safely, here.


According to the Environmental Protection Authority, bonded asbestos (that is, asbestos that has been completely covered/sealed eg by paint) can be relatively stable if it is undamaged, such as by drilling/external weathering [Source].  However, if you are thinking of renovating or replacing asbestos, there are strict guidelines to ensure it is handled and disposed of safely.  One very helpful web-site with lots of information is here.  It also has an asbestos finder tool to help identify which items in your home may potentially contain asbestos (Finder tool here).

Image: NSW Environment Protection Authority Link


Not only can poorly maintained carpets be a home for dust mites and mould, but they can contain debris, pesticides, pet dander, faecal matter and other toxins that have been walked into the home over time.  Where possible remove old, soiled carpet.  Bare floors are much easier to keep clean than carpeted flooring.  However, if your preference is for carpet, ensure it gets vacuumed weekly and any water damage/fluid spills are completely dried within 24 hours.

Image: Old soiled carpet [Source]

Damp wood – loved by termites

As damp timber is easier for termites to chew through, ensure that all timberwork that has been in contact with water (from flooding/leaks etc) has been thoroughly dried to reduce the likelihood of termite attack.


Older homes may not have insulation in the ceiling (and sometimes not in the external facing walls either).  This will lead to increased heating and cooling costs.

Newer Homes

If you’re looking at moving into a brand new home, remember that most new carpets, paints, cabinetry, flooring etc will off-gas for up to several years, and thus rooms need to be well ventilated to ensure these gases escape.


Cement slab

If a house is built on a cement slab, then the layout of the surrounding slope becomes an important aspect of the site to address.  That is, if the cement slab is on the top of a hill/mound, it won’t have drainage issues (ie from water seeking to ingress into the home from surrounding soil) to avoid.  However, if the site is flat or has one or more sides higher than the slab, then it becomes very important to get the external drainage right.  I always recommend to my clients that they over engineer their drainage so they don’t have to spend multiple times that extra cost to remediate a damp wall/room/home (with all the health consequences that can come from living in a damp house).

With brick homes, the damp course (a barrier, usually made of plastic, that gets laid across one of the lower levels of brick) also needs to be intact, as this prevents moisture wicking up and into the room(s) above.  In very old homes this may have broken down (or may never have been installed).  You can see the result from the photo below.

Image: Rising damp [Source]


Even if a home is raised on, say, brick piers, the layout of the site (whether it’s flat or has one or more higher sides) is still important as it will determine whether water coming towards the house from the surrounding ground can get away fast enough, or whether it will pool under part (or all) of the house.

Homes built close to the water (ie on sand), even if on piers, will generally have some form of impact from the constant presence of water below the home and this will require extra thought given to drainage (and may involve installation of a sump pump).

Time and time again I have done audits on homes on piers where, for whatever reason, water pools under a room or two.  Invariably those rooms will be impacted by mould due to the increased internal humidity.

Any mould that grows below a room (eg on the dirt, piers or underneath the subflooring) will be sending noxious gases into the room(s) above, either through the joins in the flooring, or wall cavities (especially where there are holes in the walls, such as for power points).

I did an audit for a home by the water in Empire Bay which was nearly 100 years old.  The owners could not work out why they had a continual problem with ants in their bedroom (even crawling on their pillows at night).  When I did the exterior inspection I noted that the ant caps (on top of the brick piers) were quite rusty and the one directly below their bedroom had actually rusted through, allowing ants easy access up and into the house.

The next article will discuss the impact of location and orientation on the health of your house.