1) It is advisable to insulate and air-seal the exterior walls of the unfinished rooms, at least down four feet from grade. This will save heating costs and eliminate condensation and the mould it feeds. To cut costs, you can use expanded polystyrene (EPS) and cover it with intumescent paint.

2) There are a variety of sleek metal and plastic doors/covers for exactly that purpose that pop off for service.

3) There's no more need to have access to pipes in basement ceilings than there is to pipes running through the walls and ceilings in the upper floors. However, do be sure to cover the pipes in foam sleeves to prevent "sweating" in summer. This is a frequent omission that you can spot by the line of water spots on the basement ceilings.

4) Put the plates on top of the XPS. The foam board provides a thermal break and keeps moisture off the wood or light steel studs.

5) The new door has to meet the Code for an exterior door. Exterior doors are typically not fire-rated.

6) Not sure what you mean by "freestanding heat". Electric baseboards work fine. But in the long run it would likely be cheaper to run new lines to radiators in the basement. (I'm assuming you have water/steam heating.)

7) In almost all basements, a mechanical dehumidifier is necessary to keep humidity levels below 50% RH in the summer.

Here is a link that might be useful: Building Science Corp. on Renovating Basements

Thanks for the suggestions. I have a few follow ups to some of the items.

1) With the EPS is that a controlled spray that fills out to a certain level so it appears consistent? I suppose I am still confused as to where the wall between the finished and unfinished rooms meet if that since there will be a difference in temperature if it will cause any condensation or mold to form?

2)Good suggestion on the coverings of the pipes. I do have about 80% of them covered but will finish the rest before the ceiling goes up. The access for the ceiling pipes is mainly due to there being a number of shutoff valves for exterior faucets and such that need to be turned off for the winter freeze.

6) Just meant a freestanding heat unit such as an infrared heater. This may or may not work due to there being multiple rooms. The reason I hadn't considered water (I do have cast iron steam heating) was due to the cost of adding a second zone off the existing and I am concerned about taking up any other room in the ceiling. Currently there are a large number of pipes in the basement ceiling that will require soffits.

Thanks

1) Expanded polystyrene (EPS) comes in boards similar to XPS. However, it has a lower R value per inch, so you need more of it to get the same initial insulation value. (However, its R Value doesn't drift lower as does XPS, meaning that eventually the difference is not as great.) The extra space used by the EPS isn't usually as much of an issue in storage or unfinished space.

Insulating the foundation walls of the unfinished rooms will keep them warm enough to prevent condensation. It's not temperature difference alone that creates condensation; it's warm air meeting a cold surface.

2) Access ports, panels and doors are available in many sizes and shapes. If you can't find them locally, lots online.

6) Electric baseboards are relatively cheap to install. However, in all the finished well-insulated basements I have done, I've never even needed to use them.

Round Access Port

This post was edited by worthy on Fri, Sep 13, 13 at 21:56

The new Owens Corning Finishing System I saw advertised covers the walls with removable panels to give you full access to the pipes. Not sure if this is necessary, but there is apparently a product to do this if you want to.