Some houses are relatively quiet while others are downright talkative. Popping, banging or creaking, especially in the dead of the night, is startling -- but in most cases, those sounds are just your home's reaction to temperature changes. You can minimize some of the racket, and if the house is new, the noise probably will diminish over time.
Sheet-metal ducting is notoriously noisy. When the furnace kicks on and hot air rushes through a cold duct, the cool metal reacts by expanding, accompanied by loud bangs. If you've ever had a baking sheet pop in the oven while making cookies, it's the same principle. If the ductwork is accessible, you can cover it with insulation or place rubber pads where the ducts make contact with wood framing or pipes. If the ducts are not easy to get to, your remedies are limited. Ask an HVAC professional if fitting the existing ducts with acoustical duct liners is feasible or if adding flexible duct transitions in the main trunk lines will reduce the noise.
In new homes, roof trusses, or the wood used to frame the attic, often is _green_, meaning it still has a high moisture content. As it dries, it can shift and contract, triggering bangs loud enough to make you think a tree fell on the roof. Those noises should decrease during the home's first year or so. In older-home attics, unsettling bangs are more likely to be the sounds of trusses, joists, rafters and sheathing expanding or contracting as the roof heats up or cools down. Metal roofs are major offenders but shingled roofs also can be quite noisy. Installing venting in an unvented attic might help because fresh airflow allows the interior of the attic to cool at the same time the outside temperature drops, which decreases abrupt wood movement. Adding insulation might diminish the _echo effect_, created by a large open attic. Sound travels through solids, though, so the bangs still can reverberate through the home's framing.
Underfoot Creaks and Squeaks
When wood rubs against wood, it can make surprisingly loud retorts. In the same way a loose step on the stairs always creaks, so does any other spot where wood makes contact with wood when you cross the floor. If a loose wood plank is the problem, drill a starter hole and insert a finish nail to secure the plank tightly to the subfloor. Then fill the nail hole with wood putty that matches the wood.
Hot water flowing through cold copper lines results in expansion popping but there are other reasons for plumbing noises as well. If your pipes shudder and clank after turning off a faucet, the problem could be water hammer_, triggered by high water pressure that surges when a valve closes quickly. The pipes react by clunking against wood framing or against other pipes. If you can reach the pipes, covering them in foam tubing can make a big difference. Your plumber also can install _water hammer absorbers on water-supply lines to help maintain steady water pressure.