When buildings are decommissioned there can be a lot of valuable materials that could be used again, but when buyers can’t find sellers, otherwise usable materials are being sent to a land fill. There is a growing amount of used building materials that can be found at online classified websites such as Craigslist and Kijiji, but finding what you are looking for can be very hit and miss.

There are also many dedicated online websites that connect buyers with contractors disassembling old buildings, or offer a place to buy and sell leftover materials from building projects and home upgrades.

On many of these sites you can search by category and location; with some (such as Sustainabuild Canada), you can also put in a request for certain materials and receive notification if what you are looking for becomes available in your region. 

This saves usable building materials from ending up in landfills, and from a financial perspective, both parties win here. Rather than paying to remove and dispose of building materials that still have life in them, contracting companies can instead receive a cheque in hand when someone comes to pick up their waste.

Much of the materials available online come from decommissioned commercial buildings rather than houses, as the quantities available are worth the effort of involving a broker. But for residential builders looking to acquire inexpensive building materials such as insulation and flooring etc, you will often get lucky. 

Reclaimed foam insulation boards
Reclaimed foam insulation boards © Michel Chenier

As an example, the above stack of XPS foam insulation was purchased through an online classified website for $3 a sheet, whereas purchased new in a building supply store they would retail for about $40 a sheet. 

It doesn’t take a calculator to know that that’s a pretty good deal, even if it requires a truck rental and some travelling time. It's dirty looking (but who cares) and the corners are not as sharp as they would be new but that is easily rectified with a can of spray foam after they are installed. Not every deal will necessarily be that great, but there is for sure money to save if you do a little digging.

The only free or cheap building material we would be careful of is wooden shipping pallets - sertain of which have been treated against insect attack by highly toxic chemicals - make sure you know how to read pallet labels to see if they are toxic or can be safely reused for beds and furniture inside, here.

There are many local companies that trade building materials, those can probably be found by doing a web search for 'buy used building materials', along with your region. Here are some sites we have found that seem to offer their services across the country, if you know of others that you have had success with, please make mention in the comments section below.  

Read more here about reclaimed and recycled building materials, building with shipping pallets and how to dispose of construction waste responsibly in the Green Buillding Guide pages of Ecohome, North America's green building website