Including a basement in plans for our log cabin was a foregone conclusion. The slope of our property, on the side of a mountain ridge, made a basement necessary. Nonetheless, we would have considered a basement as a relatively cheap way to provide additional space. We plan on a couple of bedrooms, a bathroom and playroom for the grandchildren as well as storage and the utility room.
Dampness and darkness are the two major drawbacks of a basement. The dampness is primarily due to the coolness of the basement. Good insulation is a key to a warmer basement.
Our log cabin property slope will allow us to have a walkout basement with sliding glass doors and windows on the back end. A four foot slope is sufficient for windows and eight feet will work for a walkout setup. Windows and doors will provide a source of natural ventilation and light. They also reduce any potential exposure to radon. Having them face south, if practical, also improves the natural warmth.
If possible, plan on ten foot ceilings. A higher ceiling allows for ductwork for HVAC and a less confined atmosphere. There is additional cost but the tradeoff is more than worth it. Although it is optimal to finish the basement up front, you may be facing financial constraints that currently limit your options. You can always finish off the basement in the future but you need to plan ahead. It is crucial to include plumbing lines and drains for bathrooms etc. up front.
There are several options for type of basement construction. The floor base will be poured concrete. If you are not finishing the floor, a layer of rigid insulation and radiant barrier are recommended. Alternatively, stone, tile, carpet, vinyl and wood flooring can be applied. Wood flooring should be raised off the floor.
There are a number of walls construction options.
Concrete blocks – The advantage is the price as it is cheapest option. Hollow blocks will not provide anywhere near as good a support as solid. They are also susceptible to leakage.
Poured concrete – It has no seams that promote leaks and stronger than blocks. Should be sealed on outside. However, walls can develop settlement and shrinkage cracks.
Precast concrete walls – Concrete walls can be made offsite, cured and then transported to construction site.
Insulated concrete forms (ICF) – Hollow foam forms are fitted together and filled with poured concrete. ICF is more expensive than poured concrete. Foam provides moisture block and energy efficiency as foam also blocks heat escape.