Municipal buildings have been taking advantage of the superiority of spray foam insulation for many years now. Spray foam has the advantage of being an excellent air barrier; it performs the jobs of air sealing and insulating in one step.
Federal buildings are typically in use for very extended periods of time and therefore can fully appreciate the superior lifespan of spray foam insulation. Additionally, because spray foam provides a higher R value per inch of thickness it helps to reduce wasted spaces that would be necessary for less efficient insulating products.
Also, scientists have concluded that spray foam is the most practical and successful approach for insulating both cavity and solid masonry walls. Both high density closed-cell and medium density open-cell foam create excellent air barriers and eliminate the need for separate air sealing measures.