Return to the Old House Forum | Post a Follow-Up

Adding a sun/screen porch to an old house

Posted by lavender_lass (My Page) on
Wed, Sep 1, 10 at 13:17

The old farmhouse we have was built in two stages. The original house is from 1904 and is 22' deep. The addition is from the 1950s and is 33' deep. This leaves an L-shape on the back of the house, where I'd like to add a sun/screen porch.

I don't want a solarium with a glass roof, just a porch with windows on two sides, with screens, that has a solid floor, roof and siding. The heat can be baseboard heat on a separate thermostat, electrical is not big problem and I don't need any plumbing.

The room is for a sitting area and a table with a few chairs, mainly for tea. I'll have a hutch for dishes and tea accessories and lots of plants. The idea is to use lightweight upholstered and wicker pieces, along with the wood table, to be able to expand the table and rearrange the furniture, in case we need a larger dining area. We don't do this very often, but for holidays and family get togethers, it would be great to be able to seat 8-10 people.

Does anyone have any pictures or suggestions? The roofline will be a little tricky, but should be no big problem. It's kind of an added on look anyway, so another gable will not look out of place. If anyone else has done anything like this, I'd love to learn about your experiences. Thank you!

Follow-Up Postings:

RE: Adding a sun/screen porch to an old house

What side of the house is this on? This makes all the difference, IMO, because of the impact on sun exposure. It's most neutral on the north or northeast sides. I wouldn't do this, ever, on the south, and would cautious, too, on the west because of heat.

A second consideration would be making sure both the massing and trim details are appropriate in style and scale, so it doesn't have that add-on look to it. So many porches do, and they later fall into the category often lamentedd here as something that needs to be torn off by subsequent owners.

Filling in the ell completely will change how your house looks and is experienced on the outside, if that matters. Losing the negative space formed by the intersection between the two bjuildings will make a change for the worse, at least as seen from outside. However, this can be mitigated by not filling the entire void, i.e. making the new area neither as wide nor as deep as it could be.

I presume this is under the eave, not gable, end of the house, the new roof will have to positioned well to avoid upsetting the proportions of the elevation.

On the good side, you will create a useful emergency escape route from the second floor windows.

I recommend making a scale model, or even a temporary full-scale mock-up on site in order to assess the impact on light in the current rooms.

RE: Adding a sun/screen porch to an old house

Hmmm, in cold parts of the country, a south facing sun porch is a blessing, bringing in the low southern sun as it traverses a cold sky in the winter. I think it depends a lot on the latitude where it can be well sited.

A western exposure is of course difficult, but with shade cloth and shutters and low-e glass, it can be dealt with.

Until you decide to build a sun porch, note exactly where the sun is at sunrise and sunset on the two equinoxes and the two solstices. It will be invaluable information. You might find out that your house is not oriented EXACTLY north/south/east/west, but some degrees off the cardinal directions.

RE: Adding a sun/screen porch to an old house

Actually, the house faces due southeast. The road in front of our house is a diagonal on the map, so the porch would be on the west corner...with light from the southwest and the northwest. The southwest light may be blocked by a garage some distance away, but with climbing roses or other vines growing along the side. I'd like to block the strong winds from that side and have some added privacy from our only neighbors and the road.

ML is right, when you live in the north, winter cold is more of a concern than heat in the summer. With the screens, I can open those and have a ceiling fan. Still debating on whether to include a woodstove, but that may be easier and cheaper than baseboard heat.

RE: Adding a sun/screen porch to an old house

A sunroom or porch with a western exposure may become extremely hot during the summer, although as you point out you can mitigate that somewhatby opening windows, fans and of course, the old fashioned favorite of slatted blinds (though covering the windows with slatted blinds all day somewhat defeats the light-trapping effect of a sun room). On the plus side it will protect the main house from excess heat during the hottest months when the sun is high in the northwest late in the afternoon. You may be surprised how extremely hot a west/northwest-facing sunroom can get on a long, clear day in July - in can be brutal! The downside of a northwestern orientation for a sun room is that in the winter it will get only reflected light, no direct solar gain, which may make it a chilly space.

You didn't mention whether you plan to have the space separated from the main house by walls and doorways. That would be best, because otherwise the sun-room temps, good or bad, will be a challenge to the indoor climate and the heating and cooling devices you are using. If you can close off the space when needed you can take advantage of any favorable temperature exchange, while limiting the unfavorable conditions, especially at night in the winter, or late afternoon in the summer.

In response to the suggestion that is a good thing to locate a sunporch on southern expoasure in the north: Acually having a sunporch on the southern exposure is the worst in a cold, northern climate. Not because the space doesn't get warmed directly by the sun during the day, of course it does. The problem comes when the sunporch changes the way light penetrates into the main house, creating a cave effect in the interior making it feel cold and dark in the winter. The net effect of this is to degrade the existing space in favor of the more marginal, and harder to heat, sun trap space. People often get confused by this idea, since we all know that designing a house with good passive solar orientation is great thing. It's good for energy savings, and it makes rooms very attractive and livable. But it falls down when the sun trap space projects beyond the main vertical elevation of the largest massing of the structure. This then creates the depressing, energy wasting space in the (now) deeper interior. You have to evaluate the siting on a case by case basis, as a rule, the more directly southern the exposure, the worse it is. In general, I think an eastern facing sun room is probably best in the south, and a western one (as long as it can be isolated by doors and walls) is the best choice in the north.

As far as the OP's thoughts about heating: most add-ons like this will present very complicated problems for a wood stove chimney which must be tall enough to rise above nearby taller parts of the house. From the OP's descrition of the dimensions it sounds hard to find a suitable place for such a chimney. It's always possible there's an existing location that could be used, but generally wood stove chimneys don't draft well (with all the attendant safety and air quality issues of poor draft) unless they are up in the clear. You might however consider either a propane/gas or pellet burning stove, both of which can usually be directly vented through the walls with a minimum of fuss. Electrtic heat is probably the simplest and cheapest to install, but not usually the cheapest to run. But if you are not sure how much you will use the space, then it might be a good initial choice as a trial, as the DV stoves can usually be easily added later.

I'd still recommend you create a scale model of the space and the main house (easy to do with cardboard from boxes and tape) and do a mock up. Make it big enough (at least a couple of feet) so you can look in and through it and experience the change of light you are proposing. If you like it, then you will be happy with the results, at no cost other than an afternoon spent making the model. Just make sure when you are standing outside looking through the model that it is oriented exactly the same as your house.


RE: Adding a sun/screen porch to an old house

I agree with Liriodendron, lol - I was thinking of the chimney/vent issue before he, (she? -sorry!), got to it, and had the pellet stove idea in mind - then there it was.

We installed a pellet stove a while back, for the reason mentioned. (Well, the house was dang cold & bills were HOT - that was why, lol). We went pellet instead of wood stove because we could NOT spend $$ having original chimney repaired and lined. Direct vent outside was the only way to go, for us. We were able to centrally locate it on 1st floor by, (please don't yell at me), removing an original window & frame and covering with plywood panels which DH was able to vent through without drilling vent holes into the side of house. Yes, it looks like crap right now, but we've stored the window so that it can be put back. Seemed like the least destructive option.
My only words of caution - don't let salespeople talk you into "more stove" than you need. Ours is in center of 1st floor, and directly under the air intake for furnace. With the stove blower on, we can pretty much just turn the furnace fan on & be warm w/out furnace heat kicking on. In a smaller space, without serious air-flow to the rest of the house, I can see a "sauna" situation happening. Yep, even on lowest settings. We've rarely had ours above 5, max is 10.

I agree, also, with the other postings regarding aesthics & all - but I've read enough of your posts before to know you wouldn't do anything that would look "wonky", lol! (Gee, like maybe a painted exterior plywood panel w/stove pipes coming out? I'm just embarrassed, now...).

RE: Adding a sun/screen porch to an old house

Geez... aesthetics! Missed typo earlier - went back & caught it now? I'm exhausted, and have a huge knot from lumber falling onto my head. True to form, for me. (I shouldn't work alone, lol!).

Sorry! :-)

RE: Adding a sun/screen porch to an old house

I added a porch on the west side of one of our houses and it's wonderful. We insulated the floor, the solid parts of the walls and the roof, and used sliding doors on the west and north sides with a big fixed window on the south side. It can be used without heat for at least nine months of the year here in the north east. In the summer we open the glass doors and simply leave the screen doors closed to allow air to move through it. It's lovely in there.

RE: Adding a sun/screen porch to an old house

Your porch sounds wonderful sunnyflies, can you post a picture? I'd love to see it!

RE: Adding a sun/screen porch to an old house

Sunnyflies- I'd like to see a picture, too! It sounds exactly like the porch I'd like to have :)

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Old House Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here