Started working from home. That’s difficult for all the usual reasons. Moved to a small office, no warehouse. That was nice - but became cluttered quickly with all the product moving in and out as well as the ebb and flow of boxes of wire and other consumables. We are now in a nice industrial space with office, conference room and warehouse. I forsee being able to operate from this location for the next 5 years easily.
Bottom line, working from home when you have to in order to start out is fine, but get a dedicated office as soon as possible.
500 square feet or less works for a custom installation business doing less than $300k annually. When you get busier than that you should really get some more space. I would recomment 800-1500 square feet for companies doing $300-$1M. When you get to the $1M-$5M mark you then need to really dial in your operation and you will likely need 1500-2500 square feet to handle the people and products.
A showroom is an entirely different discussion. It depends on your business model. I think most A/V companies are not focused on retail and therefor a showroom doesn’t make sense. But for those that want to compete with the walk in consumer purchase market it’s a must.
Having a show house is a nice idea - but if your work covers a large geography that only helps when you’re selling near the show house. I vote for using a video tour of work you’ve done and having samples of keypads, remotes, etc. you can let them touch.