If you're having a custom home built and need to have a heating oil tank installed, you've likely heard the arguments about putting the tank inside in the basement. The arguments behind this are valid; protecting the oil and the tank from things like frost heave and condensation are crucial to getting the best performance out of the oil. However, there is something to be said about putting the tank outside. It depends on the placement of the tank and how your basement is configured.
If your tank is in your basement, the oil delivery company has to use a fill pipe outside to add oil to the tank. That means the person doing the filling can't really see or hear anything going on with the tank unless he or she actually walks into the basement. The problem with that is the tank could be leaking without the person knowing, or the tank could end up overflowing if there isn't as much room in there as the delivery person thought.
Repair companies would also have better access to all sides of the tank if it were outside. If you have a really huge basement, that might not be an issue, but for smaller basements, access to all sides could be rather tight.
Less of an Oil-Leak Issue
If the tank begins to leak outside, even a little, that can pollute the environment. But if the tank leaks in your basement, then you have to deal with not only the cleanup of the actual oil but the fumes as well. Clothing, furniture, rugs, and other items can absorb the fumes; InterNACHI recommends getting rid of anything that still smells of the oil after a leak. There's also an explosion risk from the fumes.
Putting the tank outside might not be optimal, but it reduces the issues with fume contamination and explosion. You still face a risk outside, but it's not nearly as pronounced.
Placing the Tank
If you do decide to place the tank outside, remember to place it away from your home, in an open area where nothing is hanging over the tank. The last thing you need is for a sharp icicle or heavy branch to fall onto the tank from high up. Have a concrete pad built under the tank so that the tank rests on the pad and not on ground that could move due to frost heave.
If you have other questions about putting a heating oil tank outside your home, contact heating oil companies to see what they suggest. Local companies will be more aware of how the houses in the area tend to be configured.