Welcome to Marc t. Nielsen Interiors!
Since 1924, Marc t. Nielsen has built a reputation for exceptional design, quality craftsmanship, and personalized service. From interior design and color consulting to furniture restoration and antique sourcing, our team brings decades of experience to every project.
Since beginning her career as an interior designer in 1980, Valerie Steil has designed residences in diverse locations including Wisconsin, Indiana, Illinois, Michigan, Colorado, and Arizona. She has become a trusted voice on achieving livable interiors that are practical, comfortable, indicative of the spirit of the residents, and elegant as appropriate.
Valerie has learned to manage large complex projects, for a very discerning clientele, with the help of her capable staff, and knows the value and comfort of design that transcends time. She draws design inspiration from her extensive travels, constant reading, and her associations with other professionals, artists, musicians, cooks, and families, including their pets. Valerie walks through all the phases of the design process with confidence and grace while maintaining her humor, thus making what can be a stressful process easier, more fun and more relaxing.
Kathleen Cooper has been with Marc t. Nielsen Interiors since November of 2013. Originally from Chesterton, Indiana, she now lives in Valparaiso with her husband and daughter. Katie has a Bachelor’s of Fine Art in Interior Design from Harrington Institute of Interior Design in Chicago. She also enjoys painting and drawing in her free time, as well as making hand-drawn/painted renderings of custom furniture & interiors produced through MtN.
Margaret Collins joined the Marc t. Nielsen Interiors team in early 2026 as our new Operations Manager and Marketing Director. Margaret is a Valparaiso local and a recent graduate of Purdue University. In her position, she oversees operations and leads our marketing and communications efforts. In her free time, she is fond of knitting, painting, and spending time with animals.
Wild joined the Marc t. Nielsen Interiors team in 2016, after 9 years of living across the street. He works hard patrolling the grounds for rodents and pests, but he finds time to relax, be it by napping with Mia or watching the birds from his favorite lawn chair.
Mia started at Marc t. Nielsen Interiors in April of 2015. She is a rescue from Lakeshore Paws. Her favorite part of her job is greeting our guests, though she is very comfortable in her kennel by Valerie’s desk when we have a guest who is not necessarily a “fan” of dogs.
