As a residential architect one of the most popular issues I’m confronted with is an owner wondering whether they can (or should) renovate their unfinished attic into a living space. In this article I will dig a little deeper because while there is a lot to gain in square feet and resale value there is also a lot to think about BEFORE you begin.
When a house is built the roof structure is designed to support a roof but not necessarily a floor. Because a floor system has to support more weight than a roof its wood members are generally bigger and spaced closer together. Recently I was in a house where the ceiling was sagging and the roof was leaking. After doing some investigation I found out that the previous owner had “finished” out the attic space and added a nice big shed dormer. The problem was that the existing ceiling/roof structure was not strong enough to support the attic floor and the new shed dormer. The sad thing is the owner bought the house in part because of this finished space. Now, they’re left with some serious remedial work.
The International Residential Building Code has established minimum requirements for head height for finished spaces. There are a couple of special exceptions that allow otherwise but a good rule of thumb is that you need 7 feet of head clearance. Not every existing roof structure allows for this. So before you begin renovating it is a good idea to do some measuring and have the local building codes official visit your attic, he/she will be able to describe how the codes will apply to your space. If you don’t have the required head room it is possible to add dormers to give you more head height; this will be a more expensive renovation but still probably cheaper than breaking new ground.
One of the first things codes officials look for is required egress in and out of a space. This is so that during a fire people can get out easily and fire fighters can get in. Even more, a finished attic needs more than stairs to it, it also needs a secondary means of egress – an emergency escape and rescue opening. That emergency escape usually comes in the fashion of an operable window and it must meet code requirements for size and distance off floor. So, not only do you need to plan for a code compliant stair up into your new attic you must plan for a secondary means of egress. Often, the addition of a stair will require new beams and perhaps footings, not exactly something you want to design in the field.
There are more issues that you’ll have to consider such as: insulation requirements; minimum floor area; heating and cooling; and if you’re in a Historic district, zoning guidelines – it must be approved aesthetically. A finished attic can add square footage, home value, living enjoyment and beauty. But, it can also be bad news if you’re not prepared. Architects can help you walk through this process but so will most building officials, they want to help and they’d much rather help on the front end.