Why Camden drew a line round Primrose Hill in 1971

The idea that a whole neighbourhood, rather than a single building, could be protected for its architectural interest is younger than most of the houses it protects. It arrived with the Civic Amenities Act 1967, which allowed local authorities to designate areas of special architectural or historic interest, the character or appearance of which it is desirable to preserve or enhance. That phrase, awkward as it is, remains the legal test applied to almost every planning decision made in NW1 today.

Camden used section 1 of that Act to designate the Primrose Hill Conservation Area on 1 October 1971. The boundary was later extended, on 18 June 1985, to take in the northern part of Erskine Road. A conservation area statement setting out the area's character was adopted in December 2000 and is still used by the council in assessing planning applications. Its description of the place is deliberately unromantic: a series of well laid out Victorian terraces, residential in character but with a number of local industries, its own shopping centres and a primary school, and unusually well provided with open space because of the hill itself.

Darwin Court and the demolition that started the committee

Designation on its own changes little without someone to police it. The Primrose Hill Conservation Area Advisory Committee was set up in 1972, following a campaign by the Camden Civic Society that was prompted by the demolition of a group of fine houses in Gloucester Avenue, on the site now occupied by Darwin Court. The loss was the argument: it demonstrated, locally and concretely, what happened in the absence of any formal scrutiny.

The committee has operated on much the same model ever since. It is made up of a dozen or so volunteers nominated by organisations formally agreed with the council, and it meets fortnightly to look at planning applications made within the area. Its comments go to the council's case officers and onto the public planning record, and at appeal it puts its advice directly to the government inspector. The bodies represented on it are a useful indication of the interests in play:

What designation actually controls

A common misconception is that conservation area status freezes a street. It does not. The statutory test is whether a proposal would preserve or enhance the character and appearance of the area, which is a judgement rather than a prohibition, and the Primrose Hill committee has interpreted it broadly enough to take positions on the retention of jobs, affordable housing and the mixed-use character that keeps local businesses viable.

What designation does change is the threshold at which permission is needed. Article 4 directions can remove specified permitted development rights from houses and flats in a conservation area, so that work which would need no application elsewhere requires one here; a number of such directions apply across Camden, and the council has been reviewing those attached to its conservation areas. Statutory listing sits alongside this as a separate and stronger control. In and around the Primrose Hill area that includes most of the houses in Chalcot Crescent and the terraces of Gloucester Crescent, all Grade II; the portals of the Primrose Hill railway tunnel, Grade II* since 1974; and the Hampstead Road Locks on the Regent's Canal, listed Grade II in 1992.

The committee also functions, in its own description, as the council enforcement team's eyes and ears on the ground. Recent reports have concerned removed parapets, unauthorised conservatories, altered shopfronts and unapproved external lighting: small changes individually, cumulative in effect, and precisely the sort of thing a designation is meant to catch.

The campaigns that shaped the streets

The committee's record is a fair summary of what local conservation activism in NW1 has actually consisted of. Earlier interventions included work on Hopkinson's Place and the community centre, evidence given in the Court of Appeal concerning the former Boys' Home Chapel, opposition to an expansion by Starbucks, and opposition to a proposal by London Zoo to take ten acres of Regent's Park. More recent campaigns have sought to keep Utopia Village as a hub for small businesses, to keep the Bibendum building in use as offices, education space and gallery, and to modify and restrict the plans brought forward for the Morrisons site.

Protections older than the conservation area

The most important act of preservation in the district long predates the 1967 Act. Eton College, which owned the hill as part of its Chalcots estate, had been planning to divide it into building plots since the 1820s. On a government recommendation, the Crown Commissioners offered to buy the land in 1838; it became Crown property in 1841, and in 1842 an Act of Parliament secured it as public open space. Everything that gives the surrounding terraces their value, including the view that draws people up the slope, follows from that single decision.

A later and quieter intervention had a comparable effect on the streets themselves. From the late 1960s a number of roads in the district were closed to motor traffic after a series of serious collisions, in a scheme designed to leave the area largely free of through traffic. Taken together, the 1842 Act, the 1971 designation, the 1972 committee and the road closures explain why NW1 looks as it does: not by accident of survival, but through a sequence of deliberate decisions, each argued for at the time.