Why Aren’t More Homes Properly Ventilated?

half2Most residential building codes include sections to ensure that homes have proper ventilation, but according to the U.S. Department of Energy, “Most homes don’t meet current basic ventilation requirements and are in violation of residential ventilation building codes.” In fact, given the importance of proper home ventilation and the known formula for achieving it, it may seem surprising that one study from the Lawrence Berkeley National Laboratory found that half of American homes showed visible evidence of improper ventilation.

There are a number of reasons why so many homes do not meet even the minimum building standards:

  • Most soffit designs don’t offer enough NFA to work with today’s ridge vents.
  • Roof lines have become more complicated on modern homes, resulting in the need for more careful calculation of intake and exhaust.
  • Technical improvements have been made in exhaust technology, but corresponding improvements in intake technology lag behind. Most full vent soffit products do not allow sufficient intake (NFA) to work with the better modern exhaust products and provide the balanced amount of roof ventilation that is required for most homes.
  • Due to modern design standards with smaller overhangs, it can be difficult with most soffit products to achieve sufficient intake for the exhaust at the ridge vent.
  • A majority of soffits on the market don’t provide enough air intake. Making matters worse center vent soffit is often selected for aesthetic reasons. Many center vent soffit products decrease intake, so intake becomes insufficient to balance exhaust.
  • In many cases, builders do not necessarily follow the minimum building codes through lack of understanding or awareness of proper ventilation, and inspectors may not verify compliance with the codes.