Complex sentence: As families became seasonally established they began building cottages near the hotels; at first simple affairs replicating the rustic environment of the early camps, but later grander including in some cases housing for significant staff.
Split into simpler sentences: As families became seasonally established, they began building cottages near the hotels. At first simple affairs replicating the rustic environment of the early camps, but later grander including in some cases housing for significant staff.