Value can be expressed a couple different ways- A sheer increase in property value as reflected on an appraisal OR increased value in terms of the marketability of your home should you sell it. Of course, an appraisal is very statistic-driven, looking at such features of a home as neighborhood sales data, number of bedrooms and bathrooms, finished square footage, etc. As a realtor, I will speak to the value which comes from marketability, or in other words will a 4th bedroom make your home more valuable/desirable to potential home buyers? In my experience, buyers often favor a home that has 4 or more bedrooms. Not only do you appeal to buyers that need the extra bedroom to accommodate their family, but oftentimes buyers seek an extra bedroom that can be used as a guest room, home office, playroom or exercise room. With the set-up you described in your lower level (full bath, full kitchen, separate entry), I think a 4th bedroom might be a particular asset, as it could be marketed as a suite- for perhaps a teenager or in-laws. Just be cautious that you do not finish all your extra storage space- buyers love that too!
Carol,You have several options: There are many online real estate sites that can give you an estimate of value. I've found these sites, much like tax assessments, are based on a few data points such as sq footage, number of bedrooms, neighborhood sales data. In the matter of my own home, I found the estimates to be extremely low.You could hire a local real estate appraiser. They will establish market value of your home based on a very complete comparison of your home vs. similar homes that have sold in the area. This will be an expense of around $400-$500.Another option would be to have a local Realtor visit your home and give you an estimate. Like an appraiser, they will evaluate sales data from similar homes in the area that have recently sold. A Realtor can not only give you an idea of the market value, but also what you could, in their professional opinion, likely get if you were to sell. This is not always the same number as the market value- as the potential sales price would also factor in how many other homes are for sale in the area, how does your home's features and condition compare to competing homes for sale, what price points has the market not shown to bare (expired listings), etc. This is free and there is no obligation to use the Realtor's services. An evaluation can be done over the phone, but will not be as accurate as an in-home visit.
In today's real estate market we have two choices- appeal to buyers who are out for a "deal" (competing with distressed sales, such as short sales and foreclosures) or appeal to buyers who want a reasonably priced move-in ready home that has been well maintained. Buyers looking for a deal will be motivated by nothing other than the price of the house. Buyers that are in the market for a move-in ready home have very high expectations and usually several homes to choose from, so it's critical you partner with your agent to get the home in top condition and focus your marketing efforts on establishing value and demonstrating that you took a great pride of ownership in the home. Assuming your home will not be a distressed sale, some of items you can focus on that will get the biggest "bang for your buck" will be* Make sure the home is free of wall-paper or taste specific paint colors- neutral is always best.* Declutter and depersonalize- make sure there aren't family pictures everywhere which makes a buyer feel like they are a guest in your home instead of picturing their own family living there.* Have your carpets professionally cleaned, and stretched if needed.* Focus on your "curb appeal"- weeding flower beds, spreading fresh mulch, and setting out some brightly colored flowers in a pot on the porch will not only increase the perceived value of a home but will likely result in more showings. You don't have to figure it out on your own. There is no cost or obligation to have a Realtor come out to the home to give you an honest evaluation, our real estate team visits several homes per week and provides this service.