Conservation areas/14B

Sloane Square Conservation Area

Twenty seven acres around the square, where the Cadogan estate rebuilt the Georgian stock in red brick in the 1870s. The roofs largely survived, which is unusual, and the appraisal treats that survival as the thing most at risk.

Principal streets

Sloane Square · Sloane Gardens · Lower Sloane Street · Sloane Terrace · Sloane Avenue · Draycott Place · Culford Gardens · Cadogan Gardens · Cliveden Place · Eaton Terrace · Bourne Street · Wilbraham Place · Sedding Street · D'Oyley Street · Blacklands Terrace · Lincoln Street

Two Registers, One Area

The area is twenty seven acres and its designation history is layered: the square and its surrounding streets were designated in 1985, incorporating three small enclaves transferred from Hans Town that had been designated in 1971, with later additions. The appraisal was adopted in November 2017.

Sloane Square, Sloane Street, Lower Sloane Street and parts of the King's Road were largely built up by about 1800, and two routes on the ground can be traced on Rocque's map of 1740: the King's Road and Cliveden Place, and Blacklands Terrace, which was the southern part of Black Land Lane.

The defining event is the same as in Hans Town, and for the same reason. When Holland's leases expired the Cadogan Estate demolished many Georgian properties, and the appraisal is direct about the consequence: a significant shift from the Georgian aesthetic of the streets to the Pont Street Dutch architecture seen over much of the area today. The estate's requirement was that all buildings should be in the revived Queen Anne style and constructed of red brick.

So the area reads in two registers. The earlier terraced houses in stock brick and stucco with six over six sashes, best seen around Eaton Terrace and Bourne Street where the earliest survivors date from about 1830. And the later Victorian and Edwardian terraces and mansion blocks in red brick with terracotta, stucco or stone dressings under slate or red tile. The appraisal groups the latter as the Red Streets: Lower Sloane Street, Sloane Gardens, Draycott Place and Culford Gardens.

The Roofs Survived, and That Is the Point

Most RBKC appraisals record what has been lost from their rooflines. This one records what has not, and treats it as the thing most at risk.

The area is fortunate to have retained the vast majority of its original roof forms intact. They are of great heritage significance and make a strong positive contribution, particularly where they are present as a group providing consistent rooflines and terminations to the buildings.

The dominant form is a pitched clay tile roof with dormers and large decorative Dutch gables carrying the red brick facade upward, running along Sloane Gardens, Lower Sloane Street, Cadogan Gardens, Culford Gardens and Draycott Place, with turret features and cupolas at intervals. Butterfly roofs survive on the earlier buildings, best seen behind numbers 79 to 93 Bourne Street.

The appraisal is careful to distinguish original mansards from later ones, which is useful when arguing precedent. The mansards on the Georgian properties at numbers 2 to 20 Eaton Terrace are later, and replaced London butterfly roofs. So are those at number 2 Sloane Terrace and number 149 Sloane Street, which are designed differently, with more substantial dormers built with masonry piers and pedimented roofs.

On additions the test is the familiar one: a roof extension that stands alone in a group of unaltered roofs, or that differs in design, has a negative impact. There is also a broader warning against upward extension of any kind. Increasing the massing of the buildings with additional storeys would quickly destroy the harmonious effect and lead to oppressive and shadowed surroundings.

Glazing Patterns, Street by Street

This appraisal is the more detailed of the two on windows, and it names the streets, which means the correct pattern can be established before a survey.

Six or more panes to a sash, on the Georgian and early to mid Victorian terraces: numbers 79 to 93 Bourne Street, numbers 2 to 24 Eaton Terrace and numbers 1 to 7 Sloane Avenue, the last of these built in the twentieth century but to the earlier pattern. Eight over eight appears in Bourne Street.

One over one on the late nineteenth and early twentieth century houses, sometimes with the top sash split by glazing bars, seen to good effect along Sloane Gardens and Lower Sloane Street. More intricate designs at numbers 1 to 21 Draycott Place, where the upper panes are split into geometric patterns and the windows introduce arched heads, mullions and side hung casements. Leaded lights in side hung casements are less common, at numbers 19 and 25 Cadogan Gardens and Wyndham House on the square.

The colour is treated as structural rather than decorative. The predominantly white window joinery is called a vital element of these designs, and the appraisal states that colour, material and pattern of window joinery are all so important to the character of these streets that further erosion has to be resisted.

On replacements it objects to more than plastic. uPVC and aluminium disregard the original joinery and fail to replicate profiles, glazing bars and leaded lights. Double glazing of larger one over one sashes distorts the panes in changing atmospheric conditions and draws undue attention in the street scene, and tinted glass does the same. Both are described as discordant elements in a uniform terrace.

Six over Six and Larger
Georgian and early Victorian. Bourne Street, Eaton Terrace, and Sloane Avenue's twentieth century terrace.
One over One
Late Victorian and Edwardian. The Red Streets: Sloane Gardens and Lower Sloane Street.
Geometric Upper Panes
Numbers 1 to 21 Draycott Place, with arched heads, mullions and side hung casements.
White Joinery
Treated as a vital element of the design rather than a decorating choice.

Terracotta, Pointing and the Things That Get Painted

The material palette is the Queen Anne one: red brick with buff and red terracotta, faience, stone and stucco dressings, lime mortar, slate and clay tile, painted timber and cast iron.

Terracotta is the material most often damaged here, and the appraisal is specific. Painting red terracotta detracts from the building's appearance, creating a uniform flat finish that does not reflect the true colour and textured surface of the natural material. It notes the same problem in front basement areas, now widely painted out in white to reflect light, and done to different heights along a terrace so that it draws attention in the street.

Painting brickwork is named at numbers 1 to 7 Sloane Avenue, where the terrace has been harmed by painting at lower and upper ground floor levels and by the painting of decorative stone details. Number 7 is now the only house in the group remaining in its original state, apart from its modern tiled entrance steps.

Pointing and cleaning follow the borough pattern. Heavy weather struck pointing widens the joint, hardens the edges and darkens the building, putting the emphasis on the joint rather than the brick, and unsympathetic repointing has lost the original struck, tuck and flush forms. Cleaning damages the fabric and loses the patina of age, and a single heavily cleaned house makes the whole terrace less harmonious.

One construction detail is worth recognising rather than replacing: number 50 and numbers 25 to 43 Draycott Place have brown glazed bricks at street level beneath the upper ground floor windows, included in the original design so that walls directly adjoining the street could be washed down easily.

The Church, the Store and the River

Three buildings carry the area, and two of them are nationally important.

Holy Trinity on Sloane Street is Grade I, built between 1888 and 1890 by John Dando Sedding in red brick with stone panels and banding, Arts and Crafts Gothic. Its eight light traceried west window was never glazed as intended and remains plain; its enormous east window is by Edward Burne-Jones and William Morris. The appraisal notes that the visual primacy of its west front turrets depends on the low buildings immediately to the north, which it calls a relationship of great importance to the setting of the listed building.

Peter Jones is Grade II star, built between 1932 and 1936 by William Crabtree, and admired for its curtain walling, thin mullions, centrally pivoted windows and the splayed corner to the King's Road. Cadogan Hall, the former First Church of Christ Scientist on Sloane Terrace, is Grade II, built between 1904 and 1909 in a simplified Byzantine manner with stained glass by Arild Rosenkrantz.

The River Westbourne crosses Sloane Square station in an iron aqueduct above the tracks, which is why the platform bar was once nicknamed the drink under the river. It is joined by the Ranelagh sewer at that point. Anything below ground in this area has to reckon with both.

Two other things are worth knowing. The square's present form is modern: until the mid twentieth century the roads criss-crossed it, and the replanning begun in the 1930s was implemented after the war. And the area came very close to something else entirely. In the 1960s Cadogan proposed a forty year programme with tower blocks, a two storey shopping block over the square, and blocks of twenty six and thirty storeys, dismissed after a public inquiry.

The area, in brief

Designated
1985, enclaves from 1971
Appraisal adopted
November 2017
Extent
27 acres
Original roof forms
Largely intact

From RBKC's Sloane Square Conservation Area Appraisal, adopted 23 November 2017, and the Proposals Statement of 1991. Article 4 coverage is derived from the national planning data register, because RBKC's own per-area direction documents currently return the council's cyber incident notice. Only the borough-wide basement direction and the commercial to residential direction touch this area.

Questions

What Owners Here Ask

Can we add a mansard?
Harder here than in most of the borough, because the roofs largely survived. The appraisal treats that survival as significant in its own right and objects to any extension that stands alone in a group of unaltered roofs or differs in design. It also warns more broadly that additional storeys would quickly destroy the harmonious effect and lead to oppressive and shadowed surroundings.
Our mansard looks original. Is it?
Possibly not, and the appraisal names the cases. The mansards on the Georgian houses at numbers 2 to 20 Eaton Terrace are later and replaced London butterfly roofs, as are those at number 2 Sloane Terrace and number 149 Sloane Street. They are distinguishable by their more substantial dormers built with masonry piers and pedimented roofs.
Can we paint the terracotta?
It is specifically identified as harm. Painting red terracotta creates a uniform flat appearance that does not reflect the true colour and textured finish of the natural material. The same objection is made to painting out front basement areas in white, particularly where it is done to different heights along a terrace.
Is there an Article 4 direction here?
Only the borough-wide basement direction and the commercial to residential direction on the shopping frontages. Nothing removes householder rights over windows, doors or roofs across the area. Standard conservation area controls still apply, and so does the appraisal itself as a material consideration.

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