Short answer: To build muscle with strength training, you need roughly 0.7–1 gram of protein per pound of bodyweight per day — for a 154-lb (70 kg) person, that's about 112–154 grams. When cutting while trying to preserve muscle, the target can run a bit higher, up to around 1–1.1 g/lb, because a calorie deficit on its own raises the risk of muscle loss. Beyond roughly 1.1–1.4 g/lb, extra protein gives almost no additional benefit for muscle growth.
Short answer: Muscles grow at home under the same rules that apply in a gym: consistent training that gets progressively harder, enough protein, and enough sleep. Without a barbell, you create that challenge with resistance bands, a loaded backpack instead of dumbbells, and a slower tempo on each rep. The 4-week program below uses three full-body sessions a week, about 45 minutes each, with a clear way to get harder every week.