Thanks a lot! jon1270 Your pointed out the right problems; I don't know the answers for most of your questions. For size, I want about 500 square feet (unless additional will not cost proportionally). Exterior would be wood siding, to match the original. Shape? I would see a rectangle is most possible. Windows need to be good in order to save heating in winters. Interior material and wall surfaces would be just so-so; no need to be great. Floor is wood. Fireplace is not needed in the addition. I have no idea of foundation, basements things unless I ask a constructor to review it on-site to find out what is the best, Yes, it is on and on... I am thinking of paying a GC to be onsite to provide some estimates. Is this a good idea? Again thanks for the reply. Donald.

I think it is always a good idea to go to your town planning office and speak to someone about what would be required in terms of zoning and permits, and the schedules for obtaining those. Obviously it depends on the town, but our staff is very helpful in this regards. If your house is a typical one for the area they may also know of similar work other people have done which might give you ideas. And for us it was nice that when they saw who our architect was they were familiar with him - we needed a variance and that smoothed the process. Same thing for the contractor - our inspections have occurred without delay (fingers crossed).

My house had an existing sunroom, fully insulated and a full basement beneath. It is 8x13. The roof abutted our master bedroom. We added a bath room above it. Our existing roof was in good shape and our siding and roofing tiles were still available. No plumbing preexisted on this side of the house so trenches had to be dug in our front yard through walk way and driveway. Both of those cost close to $10 k to replace. Our costs without counting the architect, 5k, driveway and without having to reroof whole house and reside whole house( if we could not have matched roofing it would have added 7k) was $67,000. We provided and made our vanity out of an antique dresser thereby saving thousands and we painted walls, ceiling and wood work ourselves, estimated painting cost were $1900. We did no bath tub and very little frills. Here are pictures of before and after. We lost a lot of curb appeal bathroom is pretty basic but has great natural light.

You need both a defined budget and an architect it is hard to determine costs and benefits without actual plans. I worked with an architect when undecided between adding a fourth bedroom with a bath in the attic or just adding a small second floor addition above a ground level sunroom with foundation that was adjacent to our present master bedroom to add a bath. I paid for both plans than interviewed contractors and got precise bids. The smaller Sq foot plan cost 75k less than expanding into an unfinished attic would have but we did not get a fourth bedroom.