Growing demand: South Shore rents are highest since dot-com era

Landlords of high-end office properties in the Quincy-Braintree area are asking for rents not seen since the dot-com era, as even higher rents in downtown Boston and MetroWest drive tenants to buildings south of the city.

Some landlords are seeking rents in the mid- to upper-$20-per-square-foot range. And those prices could be topped by a large speculative office project rising in Braintree, in a reflection of developer Thomas Flatley's faith in the market's continuing vitality.