My son-in-law built a deck onto their home and made it about 3 times as big a I thought it ought to be. Guess what? I was wrong. The deck has been a marvellous addition to their home and it is a real party place. They have since put in a pool and had to cut the deck back a little, but it was easy to adapt. Also, they have put an outdoor kitchen in a gazebo at the corner of the deck. I would say, bigger is better. Lots of seating, table and chairs, propane heater covered area -- all take lots of room. Have fun with the design.

We're planning our deck now too. Our house is a 1 story smaller home. We originally thought a concrete slab 10'x 30' along the back of the house would be plenty when the house was built. Not realizing that there would be 2 sets of steps from french doors in the family room and bedroom. My husband thought adding 5' would work and then I asked him to move things where we would want them - ie the rectangular patio table, grill etc. We so far expanded to 25'x 40' and have used the orange landscape paint to draw the outline on the grass. At this point it is still under discussion.

The size really doesn't have that much to do with the size of the house but more with how you intend to use the patio. 12'x12' are the minimum dimensions to accommodate an outdoor patio dining set that seats 6 and still feel "comfortable". Less than that and you will start to feel cramped in the space or that chair legs may fall off the surface.

And you will probably want room to accommodate the BBQ and perhaps some lounge furniture as well. Allow enough additional space for adequate circulation across the patio without running into furniture. And maybe a container planting or two to spruce it up. In short, if used for entertaining it should have no less than the square footage of an interior dining room. Err on the side of generosity :-)

My enclosed (fenced on 3 sides, house on the 4th) patio is approximately 16 feet wide and 35 feet long. Part of this total space is taken up by largish deck-like landings from the house down to grade. With a 4 person dining set and a couple of lounge chairs and side table and an assortment of container plantings, it is none too big.

I agree, bigger is better! You can always fill up empty space, but you can't always expand.

I had a deck built across the back of my house. I wanted it to be at least 13 feet deep, but the builder talked me down to 12' since that's a normal size for wood. I regret that decision, since the 12 feet doesn't really give me room for a table for 4-6 people AND space to walk by comfortably. So I added room in the garden for the larger table, and now have a smaller table with 2-3 chairs on the deck.

Also, if you're going to barbeque, you'll probably want storage space nearby. And more 'counter space' either near the barbeque and/or near the table.

I read once that since the sky will be the 'ceiling' of your outdoor room, a bigger floor space than you would normally have for an inside room feels more comfortable.

If you don't already have your outdoor furniture, take your indoor furniture out on a nice day, and arrange it so it's comfortable, and then measure the space you have used up. (Don't forget to add space for pots and planters.) I bet you'll be surprised at the dimensions.

Daphne in Tacoma

using indoor furniture for outdoor like patio is not too good idea. Because we know well the indoor furniture is not designed as well as like outdoor pieces of furniture, particularly about durability issue.

Here is a link that might be useful: chair