Additions come in all shapes and sizes. The smallest one we’ve done was a mere 8 by 10 feet. The largest one was over 3,000 square feet. We have done many in the 2,500 square foot range, too.
People ask me what the average square foot price for an addition will be, but the answer depends on what you are building. A simple sun room and a master suite addition have completely different square foot prices, because there are a LOT of variables involved.
A few peripheral things that can also affect the price include whether the addition will be built on a slab, whether it will have a crawl space, whether it will have a basement, and so on. What level of “finishes” will the addition have? Will it have hardwood floors? What type of windows and siding will it have? What about standard millwork or custom woodwork? These are all factors.
The single best thing you can do is to establish a budget for your addition. Find a contractor you like, check references, and visit at least one of their jobs. Choose an architect or have your contractor suggest one. Then your project can be accomplished within your budget (or it can’t, in which case you’ll have some choices to make).
I do some of my best work when I have the opportunity to confer with both the owner and his or her architect. My experience helps, too. If I’m involved from the earliest stages, I can make sure you don’t design a job that demands work outside your budget.