Tract housing has one advantage when it comes to diagnosis: the problems repeat. Streets here went up in batches, each batch built to what was normal at the time, with the same framing details, the same attic access, and the same duct layout house after house. If your neighbor has a cold back bedroom, there is a fair chance you do too, and for the same reason. We connect homeowners across Salt Lake County with insulation contractors who have been in these houses many times. Call 801-644-9000.
A production builder solves each detail once and then repeats it down the block. That is efficient, and it means the shortcuts repeat as well. In a run of similar homes we tend to find the same short list: an attic hatch with nothing on it and no weatherstripping, a dropped ceiling over the hallway or a soffit above the kitchen cabinets that opens straight into the attic, insulation that stops before it reaches the top of the wall shared with the garage, and heating ducts run through the attic with their joints sealed lightly or not at all.
That repetition is useful to you. If a neighbor has had work done, ask what was found rather than only what it cost, because the findings will probably apply to your house too. It also means a contractor familiar with the neighborhood can tell you before going up what he expects to see, then confirm or correct it once he is in there. What you want from an inspection is a list of specific locations with specific problems, not a general recommendation to add more of something.
Homes built in the decades after the war were insulated according to what was expected then, which was less than what is expected now and focused almost entirely on the ceiling. Walls received whatever fit in a shallow cavity, if they received anything. Air sealing was not really a step anybody performed as its own task. That is less a defect in the house than a snapshot of ordinary practice at the time, and these houses have generally held up well. It does mean there is usually real room to improve, and that the attic is where improvement is easiest.
Where it gets less straightforward is the walls. Cavities may be narrow, there may be blocking partway up, and the exterior finish determines both how the work gets done and what it costs to put right afterward. Sometimes that is worth doing. Sometimes the money goes further sealing and topping the attic and dealing with the garage wall, and the walls can wait until siding is replaced. Anyone who tells you to do everything at once in a house like this is selling to you rather than diagnosing the house.
In many of these homes the heating ducts run through the attic, above the insulation, in a space that sits close to outdoor temperature most of the year. If those ducts leak at the seams, at the plenum, or at the boots where they meet the ceiling, the system pushes conditioned air into the attic and draws attic air back into the house. You feel that as weak airflow at the far registers, rooms that never catch up with the thermostat, and more dust than seems reasonable. No amount of insulation over the ceiling changes any of it.
So this is worth saying plainly: a good deal of what gets sold as an insulation problem is not one. If your registers blow weakly, if the system runs almost constantly, or if one room is comfortable and the next is not despite similar exposure, have the duct system looked at before you add material overhead. Sealing and properly burying the runs, or repairing sections that have come apart, may do more than anything else on the list. A contractor who checks the ducts while he is up there is doing you a favor.
Usually. The common method is drilling a series of small holes, filling each cavity through them, and patching afterward. How well it works depends on what is already in the wall, whether framing or blocking divides the cavity into sections, and how the exterior is finished. In houses built in runs, a contractor who has done one on your street can generally predict what he will find. Ask to see how the patching is going to look before you agree to it.
Often, since houses built together share their weak points. Confirm it rather than assume it. Your house may have had a different owner, a different remodel, a bath fan rerouted, or an attic somebody already topped off. Have someone go up and look at yours specifically. A neighbor's good result is an excellent reason to inspect, but it is not a substitute for inspecting.
Generally yes, because once material has been blown over them they are much harder to reach. Sealing the joints and boots, reconnecting anything that has separated, and then burying the runs under the insulation is the right order of operations. If the duct system has never been looked at, start there. In houses like these it is often where the comfort complaint actually originates.
Cold rooms, drafts, ice at the eaves, or an attic you have never been in. Any of it is a place to start.