About 15 years ago I purchased my first home spa. Back then the Town of Truckee did not require permits to install spas and hot tubs, but the electrician and the retailer of the spa did needed to follow certain codes to ensure a safe environment for the potentially deadly combination of electricity and water. In 2010 I started working with commercial pools and hot tubs and eventually residential tubs. Soon after that I realized not all contractors and installers followed the codes. It is amazing to see some of the locations tubs have been installed and the potentially dangerous electrical situations that have been created. Below are a few of safety issues I have seen, but is not an all inclusive list of the requirements that will be inspected when a permit is obtained.
One location that could create a problem is against an exterior wall with windows that do not have tempered glass. These days most glass in residential windows is tempered, but in the case it is not, several safety concerns can apply. Tempered glass breaks into small relatively harmless pieces. So, if someone slips and breaks the glass it will break into the small bits, rather than huge hunks that can cause serious injury. Tempered glass is more temperature resistant. This a concern because of the cold air temperatures we have, this mixed with the possibility of hot water splashing on the glass, can causing it to break due to the temperature differential. The tempered glass has a higher differential making it safer. As mentioned most glass in windows these days is tempered, but why take chances.
The most dangerous concern is regarding the mix of water and electricity. It is required to have a disconnect with in 5 feet of the edge of the hot tub. Without the disconnect the only way to cut the electricity is to go to the breaker and this takes time. The problem with this is that it encourages the maintenance to be done with the electricity on. Not smart, and many of the tubs I do maintenance on don't have the disconnect.
Another electrical requirement is that all outlets within 5 feet of the tub need to be GFI protected. It just like outlets in your kitchen or bathroom that are near water. Its smart and more safe. It is worth the cost of a new breaker or outlet to protect your family and friends from being injured or worse.
All in all, from what I have seen, my recommendation is to find qualified contractors that have no problem obtaining the permit for the installation of your hot tub. This will ensure the safety of your loved ones and protect the investment of the hot tub as well.