Yes, and for most homes in Chafford Hundred, heritage rules won't get in the way. Most of the estate is too young to be listed. The one conservation area is at Purfleet. The ground needs more care than the planners do. Clay will give you more trouble than history.
Historic England lists 32 buildings across the area this page covers: 4 at grade I, 1 at grade II* and 27 at grade II. Listing protects the whole building, inside and out, so almost any change to one needs listed building consent from Thurrock Council on top of planning permission, and a replacement window can mean a conversation with a conservation officer. Very few of the 32 are on the late twentieth-century estate. People have lived on this land since the Middle Stone Age, and the quarries that came much later dug out most of the ground they lived on.
There is one conservation area in the area covered, at Purfleet. Inside it, the council can expect extra consents for changes that would be routine elsewhere, such as demolition, work to trees and alterations that change how a street looks. A buyer on the estate itself is unlikely to be affected. A buyer in Purfleet should find out which side of the boundary the house is on.
There are 3 scheduled monuments in the area, the strictest tier of heritage protection. They matter for land on or near one and to nobody planning a rear extension in a cul-de-sac.
Thurrock Council's register shows 1,007 planning applications here between April 2024 and June 2026, including 478 in the last twelve months. That shows plenty of people are altering their homes, and the council's planners have seen most ideas from this estate before. A loft or a side extension here will have a precedent a few streets away.
The ground is the real constraint. The national geological survey puts the area at shrink-swell class 3, and about 99% of it reaches that class. This is a published hazard rating for clay that swells when wet and shrinks when dry, which moves foundations that are too shallow. In practice, an extension here needs a structural engineer to set the foundation depth, and building control will expect the design to account for the clay. That is a cost for the budget, and nothing to panic about. Get an engineer's opinion on the foundations before the architect draws anything.
In practice, most houses here can use permitted development rights for modest rear extensions, loft conversions and outbuildings within the national size limits, with no heritage overlay to remove those rights. Anything larger, anything at the front, or anything on a listed building or in the Purfleet conservation area needs a planning application. Many homes here are flats, and flats have no permitted development rights for extensions, so a flat owner needs permission, and on a leasehold flat the freeholder's consent as well, for most changes.
Freedom to extend in Chafford Hundred is about average. Heritage barely gets involved, but the clay and the paperwork mean nothing here is completely straightforward.