Many folks add on a Sun Room to their home. They can be very nice additions to a home and functional as well. However, think carefully before you add on such a room, as a screen porch may be a much cheaper and more desirable alternative.
A screened porch, is, as the name implies, a roofed structure with a screened enclosure, open to the elements. A Sun Room is a glassed-in structure, often with sliding doors with screens, that is enclosed. The two are radically different beasts, and you should think carefully before choosing one over the other.
The temptation is, when screening in a porch, or if you have a screened porch, is to "covert" it to a Sun Room, three-season room, Florida room, or the like. In many cases, this can be readily accomplished by replacing the screen sections with sliding glass door panels.
Or, if you are building a screen porch, the salesman may suggest building a Sun Room instead, on the premise that "you will get more use out of it" and that the incremental cost is not that great, and it will add value to your home. The salesman will say the room will be "like a screened porch" if you open up all the windows. But the salesman is wrong on all counts.
I recently was given a book by a friend, on smaller homes, and the editor of that book made a good point. People glass-in screened porches, and then try to make them into living space. They quickly realize that the space is hot in the sun and cold at night or in cold weather. So the owner puts in space heaters and an air conditioner, and suddenly, they have a room that is a utility bill nightmare to heat and cool.
They then move their furniture out into the Sun Room, leaving the living room or family room as this unused space between - a space that is just walked through and not used, and ends up as a wasted-space junk accumulator in the house. And of course, they end up putting the TeeVee out there, as it ends up being the place they hang out. But the light through all that glass reflects off the TeeVee screen, so they put curtains or other window treatments over the windows, effectively making the Sun Room into a dark room.
So, what started out as a screened porch - a nice spot to sit in the shade, out-of-doors, away from the bugs, ends up turning into this nightmarish addition made of a conductive material, nearly impossible to heat or cool, and kept dark with window shades.
And of course, the homeowner, now in this situation, starts to think, "Gee, maybe what we need is a screened porch built off this porch!" and the whole process repeats itself all over again, with the house becoming one addition after another.
Let porches be porches, the author suggested, and it made a lot of sense to me. The point of a porch is to be in the environment, in the outdoors, not in an enclosed space or indoors. Once you "glass in" a screened porch, it becomes something that is not a porch. And the room leading to it becomes useless.
A screened porch, on the other hand, is a quasi-outdoor space, used only when the weather permits, and as such, does not end up dominating the home. The living room remains the living room, and the porch remains a porch.
As I noted, over the years, we have built three of these "aluminum rooms" and one is under construction as we speak. The screened porch is probably the most cost-effective of the three. There are advantages and disadvantages to all types, but the screened porch has a lot of advantages over the Sun Room:
1. Cost: A screened room can be less than half the cost of a Sun Room, as screened panels are very cheap to make. Our first sunroom, 18' x 24' cost $28,000 back in 2000, and used double-insulated glass, a 6" foam panel ceiling, and a complete deck underneath. Our next room, about 10' x 15', cost $10,000 with single-pane glass, a 3" expanded paper panel roof, and no foundation work required, back in 2002. Our present room, about 15' x 15', with a simple "pan" roof, screening, and two doors, will run about $6000 with some concrete and prep work. Screened rooms are far less expensive to build, that is clear.
2. Permitting: A Sun Room is living space and as such required building permits, which take time and cost money to obtain, as drawings are needed, along with permit applications. Codes must be followed and inspections made. A building permit, of course, is just a tip-off to the county to have your home re-assessed, so expect your property taxes to increase as well.
3. Electric: As living space, a Sun Room requires outlets about every 6 feet on all walls. For exterior walls, this often means floor outlets. You also need lighting and a switch as you enter the room. So add the cost of an electrician to the mix as well.
4. HVAC: Again, the temptation is to "expand" the season of a three-season room by adding heat or air conditioning, and as an all-glass and aluminum room, this gets expensive. We used strip heaters in one room (the most expensive way to heat possible) and in the winter, the aluminum frame around the double-paned glass would ice over - sometimes inches thick. In the summer, we used a 220V 25,000 BTU air conditioner (window unit) installed in the base panel. It was loud and consumed a lot of energy and really didn't cool the room all that well. Trying to make these types of rooms into living space is a task in expensive futility.
5. Little Increase in Resale Value: The Sun Room salesman might argue that adding such a structure increases resale value of the home, but that is a largely specious argument. Really expensive Sun Rooms might add some value (stick-built type) but then again, perhaps less than 50 cents of the construction cost - perhaps less. So you spend $50,000 putting a pretty amazing Sun Room on your home, and it increases the value of your home only incrementally - perhaps $25,000. A $10,000 screened porch adds maybe $5,000 in value, so you end up spending a lot less, in real terms.
Now, don't get me wrong, we enjoyed our Sun Rooms. But we found that the cheaper the room, the more we enjoyed it. The monster sunroom was nice, but it was never a real living space, other than for occasional parties. And as a screened room, it was too "indoorsy" to act as a porch.
We also learned, the hard way, that it is very easy to over-improve a home. While you might think you are "adding value" to your home by adding on a Sun Room, all you are doing is pissing away money, in terms of recovered cost. The addition to the home will not add as much value as you spent on putting it on. Over a decade or more, perhaps you may eventually recover the cost, if inflation increases the value of the home, but even then, perhaps not. If you want a house with a Sun Room, you are better off just buying such a home, rather than spending tens of thousands of dollars adding on to your existing one.
We build the screened room we have today to replace a screened tent over our hot tub (a portable tub known as SoftTub). Viewed in that light, it is a nice room at an attractive price, providing us with a place to sit on warm evenings (or during the day) and a way to enjoy the outdoors at our home, without being carried away by the bugs we have here. A Sun Room or glassed-in room would have cost considerably more and provided less of what we really wanted. And since the hot tub tends to slosh water, we would have felt that having it "indoors" was a bad idea - and ended up building a screened room to contain that.
Let porches be porches! The beauty and enjoyment of a porch is that it is not a three-season or all-weather enclosure, but rather a room for use when the weather is pleasant - a way of enjoying the outdoors. If you build a Sun Room, bear in mind that you will not have that enjoyment, as the room will be indoor space.
UPDATE: Photos of the finished room can be found here. We are very happy with the room, the speed of construction, and the low cost. The best feature is being "outdoors" without the bugs. And no, a glassed-in room doesn't provide that effect. They are nice, but more like being in a fishbowl..