I am looking for a solution to hide the power cord and A/V cables from my wall-mounted TV. I know that putting power cords or extension cords behind the wall is not permitted. I've seen several kits like these that claim to comply with the building codes:
They need to be CUL or CSA approved for Canada. UL is also nice but only applies to the US. There may be other approval codes for various regions, countries or states. CUL, CSA and UL are safety ratings only. They do not guarantee that the product is good quality otherwise.
These products seem overpriced. Data cables require no special handling and merely need to be wall or plenum rated. A couple of wall plates is all that is required. Outlets need to meet the local electrical code and would usually require less than $20 in materials. Hiring an electrician to install an outlet in an existing wall would result in a higher price. In any event, care must be taken on exterior walls to keep the vapour barrier intact.
In all honestly, they are a "kit" so it is for the beginner who does not know how to do it themself, if you are a handy man, you can easily put a junction box and a low voltage caddy behind the TV, and fish the wires down the wall and put boxes on the other end. The only difference between this kit and someone doing it themself, is a professional would extend the electrical circuit right behind the tv and put a live electrical outlet there. the kits do not connect to a live hydro circuit, they have a female plug behind your TV but they also have a male plug low to the ground and you have to put a extension chord from the low box to a live electrical outlet or you can use it to plug the tv into a surge protector if you wish. That is really the only difference, and the fact you are running low voltage cables behind the wall too.
Some expertise is still required to install them correctly. (120v connections are required at each wall plate just as it would for any receptacle and the wall must be opened and fished.) The other difference with the kits is price. They are charging close to $100 for parts that are worth significantly less than $50 at retail. The wall plates may be difficult to find or custom made but similar parts are typically under $10. The kits look like a good option for people who don't want to hire an electrician but they are being gouged, not saving much in labour and getting a second rate solution.