Can we add a cellar to our barn conversion?

We are hoping to begin converting three derelict barns, using the largest one as our family home. It has a partial concrete base with soil at the far end. Can anyone advise as to the logistics of adding a cellar to this structure? It’s certainly possible to add a basement structure and it’s good to consider this before you start on your conversion project. First of all, you need to decide what you need the extra room for. If it is merely a wine cellar, you can buy prefabricated units that fit into a reinforced surround and take up a relatively small area.

If you want a more substantial zone, you should perhaps weigh up whether the expense of putting in the basement will provide a return on investment. For example, does it increase the value of the house and/or does it provide you with much needed space that cannot be achieved elsewhere in the home?

As long as it stacks up, it would likely be best to build the new basement by supporting the existing barn structure while excavating the hole. This can be done sequentially if you plan to dig directly in line with the existing outer walls, but it will be easier if you choose not to follow the outer line of the building and stay well within its exterior, like for the wine cellar option.

You will need a structural engineer to advise you on the best strategy for creating the basement. Generally, they are more expensive to construct compared to above ground walls, as you have to support other structures or surrounding ground, remove spoil, cast a reinforced slab and tank the space to manage water ingress. Explore the design and get an assessment of likely costs before you decide to commit to the works.