Matching Bricks for London Extensions: How to Identify, Source, and Match Victorian and Edwardian Brickwork

**London Stock Brick (the yellow-grey-brown bricks of most pre-1880 London terraces)**:

London Stock Brick is the defining brick of Georgian and early Victorian London — the yellow-grey-brown bricks visible in the vast majority of London terraces, warehouses, and public buildings built before approximately 1870–1880. Stocks are made from London Clay with the addition of chalk and ashes (the 'Spanish' or 'refuse' that gave stocks their distinctive mottled, variegated colour), fired at relatively low temperatures, which creates a soft, permeable, slightly irregular brick with a distinctive colour range from pale yellow through buff, brown, orange-brown, and dark grey-brown.

• *Key characteristics of London Stock Brick*:
• •Colour: highly variable — typically a mix of yellow, buff, brown, orange-brown, and dark grey-brown tones within the same wall. The variability is a key aesthetic feature — new bricks with uniform colour do not match stocks well
• •Dimensions: typically 225mm × 112mm × 65–70mm (roughly 9" × 4.5" × 2.5–2.75") — slightly larger than modern metric bricks (215mm × 102.5mm × 65mm). The coursing of original stock brickwork is often at a slightly different gauge than modern brickwork — a source of mismatch even when the brick colour is correct
• •Texture: rough, irregular surface with visible sand facing or wire-cut texture on many types; some stocks have a more uniform surface. The texture variation within a wall is another key characteristic of authentic stock brick
• •Mortar: original Georgian and Victorian stock brick walls were pointed in lime putty mortar — typically a 1:3 lime:sand mix (lime putty to sharp sand). The mortar colour is typically pale yellow to cream, buff, or light brown depending on the local sand used. NEVER use OPC-based mortar on original London stock brick walls — it is too hard; it cannot accommodate movement; and it can cause spalling of the softer stock bricks (the mortar must be softer than the brick)
• •Permeability: London stock brick is very permeable and breathable — it absorbs moisture and releases it. Extensions using modern dense wire-cut bricks or engineering bricks adjacent to stock brick can cause water to be driven into the stock brick rather than being shed — a common source of dampness and frost damage in poorly specified London extensions

*Where London stock brick is found*: pre-1880 terraces in Inner London (Islington; Hackney; Southwark; Lambeth; Camden; Hammersmith; Kensington; Chelsea; Westminster; Greenwich)

**Red London Brick (the red bricks of late Victorian and Edwardian terraces, approximately 1870–1914)**:

From approximately 1870, red bricks made from Midlands clays (particularly Staffordshire and Leicestershire bricks, including the famous 'Hawkins Red' and 'Staffordshire Blue') were increasingly used in London as the railway network allowed Midlands bricks to be transported economically. London Brick Company's Fletton brick (made from lower Oxford clay near Peterborough) also became widely used from the 1880s and dominated the post-First World War London housing market.

• *Key characteristics of late Victorian/Edwardian red brick*:
• •Colour: range from bright orange-red through medium red to deep red-brown. Some bricks have a sand-faced or rustic finish; others are smooth wire-cut; others are 'Multi' bricks with deliberate colour variation
• •Dimensions: 215mm × 102.5mm × 65mm (modern metric equivalent) — or near to it for late Victorian bricks. Edwardian brick dimensions are generally very close to modern metric, making coursing a less significant issue than with stocks
• •Texture: varies — rustic hand-made or sand-faced bricks have a textured, irregular surface (more commonly used in Arts & Crafts influenced London Edwardian terraces); smooth wire-cut bricks are more uniform
• •Mortar: late Victorian and Edwardian brickwork typically uses a mix of lime mortar and early OPC (ordinary Portland Cement), particularly after 1900. Mortar colour is typically buff, grey-buff, or slightly pink — less yellow than pure lime mortar on stock brick. Modern matching brickwork on Edwardian properties should use a slightly weaker cement:lime:sand mortar (e.g., 1:1:6 or 1:2:9 cement:lime:sand) or hydraulic lime mortar

*Where Edwardian red brick is found*: Inner and Outer London Victorian and Edwardian terraces (Ealing; Walthamstow; Lewisham; Tooting; Balham; Crouch End; Stroud Green; West Norwood; Chiswick; Richmond; Wimbledon; Surbiton)

**Inter-war London brick (1920–1939)**:

The dominant inter-war brick in London suburban housing is the London Brick Company (LBC) Fletton Brick — a smooth, slightly pink-orange wire-cut brick fired from lower Oxford clay. Fletton bricks are uniform, regular, and smooth compared with Victorian bricks. Fletton bricks are no longer in production — the LBC closed its last Fletton works in the 1980s. However, the very large quantities of Flettons produced means reclaimed stocks are still widely available.

*Identifying inter-war brickwork*: regular coursing; smooth wire-cut surface; slightly mottled pink-orange-cream colour (not as vivid red as Staffordshire bricks); typically cream or buff mortar joints.

**The challenge of brick matching in London**:

The main challenge with brick matching in London is that the bricks in most Victorian and Edwardian terraces are either: 1. No longer manufactured — London stock brick production effectively ceased in the early 20th century as the brick kilns in South and East London closed. No modern manufacturer produces a brick that replicates the variability, colour range, and texture of original London stocks 2. Out of production from the original source — Staffordshire and Midlands red bricks from specific Victorian-era kilns are no longer available as new production 3. Produced in small quantities by specialist manufacturers at significantly higher cost than standard new brick

*The three brick-matching strategies for London extensions*:

**Strategy 1 — Reclaimed matching bricks**:

Reclaimed bricks sourced from demolished London buildings are the most authentic match for London stock brick and red brick extensions. Reclaimed London Stock Bricks and reclaimed Victorian/Edwardian red bricks are widely available from London salvage yards.

• *Sources for reclaimed London bricks*:
• •Lassco (East London and Surrey): one of the largest London architectural salvage dealers; large stocks of reclaimed London stocks and Victorian red brick; delivers UK-wide
• •Retrouvius (North London): specialist in reclaimed architectural materials including brickwork
• •Southgate Building Materials (Palmers Green, North London): large stock of reclaimed bricks
• •Thornton Kay / Salvo network: online directory of UK salvage dealers with searchable brick stock
• •Local London salvage yards: in any year, numerous demolition projects in London produce reclaimed brick stock — asking the main salvage dealers what is currently in stock is the most reliable approach
• •Local brick reclamation: if a neighbouring property is being demolished, reclaimed bricks from the same terrace or from the same locality are the most authentic match. Approach the demolition contractor.

• *Considerations when sourcing reclaimed bricks*:
• •Quantity: allow 20–25% wastage on reclaimed bricks (damaged, broken, or unsuitable bricks within any batch). Order more than the net quantity required by at least 20%
• •Condition: inspect a sample before ordering. Key quality checks: no spalling faces (frost damage to the brick face — brick will deteriorate further if used in an exposed position); no deep mortar keying (brick has been pointed at the face — fine; brick with deep holes or channels where mortar has been applied is structurally weakened); salt efflorescence (white salt deposits on the face — may indicate the brick came from a chimney and contains sulphate contamination; do not use these in structural walls)
• •Sand-facing vs. cut face: some reclaimed bricks will have been cut in their original use (to create closers, specials, or cut bricks for reveals) — include an allowance for specials in the quantity estimate
• •Cost: reclaimed London stock bricks typically cost £0.80–£2.00 per brick (supply only); reclaimed Victorian red brick £0.50–£1.50 per brick. Prices vary significantly depending on rarity of the specific brick type and current availability

**Strategy 2 — New matching bricks from specialist manufacturers**:

A number of specialist brick manufacturers produce new bricks designed to match London historical brick types:

• *For London stock brick matching*:
• •Ibstock Beacon Hill Yellow Stock: the closest new-manufacture approximation to London stock brick — a soft mud-process yellow stock with colour variation from pale yellow to buff to brown. Widely used by London Boroughs and developers for conservation area extensions. Not a perfect match for all stock brick types — a sample panel should always be approved by the LPA conservation officer before proceeding in a conservation area application
• •Wienerberger London Stock Range: several products including 'New London Stock', 'Olde London Stock', and 'Imperial London Stock' — mottled yellow/buff stocks with varying degrees of colour variation
• •HG Matthews (Bellingdon Brick, Chesham): handmade soft mud bricks in colours approximating London stocks — premium product; very high quality; made from similar clay beds to original London stocks. Significantly more expensive than Ibstock stocks but much closer in appearance and texture to original Victorian stocks. Often specified for conservation area extensions where the LPA conservation officer requires a closer match than standard Ibstock products can provide
• •Petersen Tegl (Danish manufacturer): premium hand-formed bricks in various warm yellow/buff tones that approximate London stocks — used on high-spec conservation projects. Very expensive; not typically specified for standard residential extensions

• *For Victorian/Edwardian red brick matching*:
• •Ibstock Leicester Multi Red, Bingley Red Rustic, or Chilmington Red: common Ibstock products used for matching late Victorian and Edwardian red brick. The Multi Red products offer colour variation that helps blend with weathered Victorian brickwork
• •Wienerberger Terca Accrington Nori, Clanfield Red Rustic, or Stamford Red Multi: alternative Wienerberger products for red brick matching
• •HG Matthews: also produces red brick variants — premium quality
• •Reclaim-look new bricks: some manufacturers produce 'olde English' or 'rustic' bricks with textured, aged-looking surfaces designed to minimise the visual contrast between new and existing brickwork

**Strategy 3 — Blended approach (part new, part reclaimed)**:

A common practical approach for London extensions where the extension is visible but not in a conservation area: use a specialist new brick as the main specification but blend in a percentage of reclaimed bricks (15–25%) for colour variation and to reduce the uniformity of the new brickwork. This is significantly cheaper than sourcing the full quantity in reclaimed brick while producing better visual results than 100% new brick.

**Mortar specification for London brick extension matching**:

The mortar joint is at least as important as the brick colour in determining whether an extension matches the existing property. Key mortar matching decisions:

• *1. Mortar type*:
• •On original London stock brick (pre-1900): specify hydraulic lime mortar (NHL 3.5 or NHL 2) or lime putty mortar. Do NOT use OPC mortar — too strong; causes spalling of stock brick
• •On late Victorian/Edwardian red brick (post-1880): specify a weak cement:lime:sand mix (1:2:9 or 1:1:6) or hydraulic lime (NHL 3.5). Slightly stronger than pure lime but still weaker than modern OPC mortar
• •On inter-war (1920–1939) London Brick/Fletton: can use a standard cement:lime:sand 1:1:6 or 1:2:9 mix; avoid pure OPC mortar which creates visible bright grey joints inconsistent with weathered inter-war brick

• *2. Mortar colour*:
• •The sand used in the mortar largely determines the mortar colour. To match light buff/yellow mortar on London stocks: use light buff sand (silver sand or similar) with lime putty. To match darker buff/brown mortar: use yellow or brown builder's sand. Consider adding small quantities of brick dust or red ochre to adjust mortar colour
• •Never use standard bagged grey OPC mortar on matching brickwork — the grey colour of OPC mortar bears no resemblance to Victorian lime mortar

• *3. Joint profile*:
• •Victorian London stock brickwork: typically struck/flush or lightly weathered joints; sometimes recessed joints on higher-quality houses
• •Victorian/Edwardian red brick: typically struck or bucket-handle joints
• •Do NOT use 'strap' or 'ribbon' joints (wide projecting mortar bands) on Victorian or Edwardian London matching brickwork — this is a modern style inconsistent with historical brickwork

**Why brick matching matters in conservation areas**:

• In London conservation areas, the choice of external materials (including bricks) for a new extension is almost always a planning consideration — either as a planning condition on the planning permission, or as a design requirement in the Conservation Area Character Appraisal. A poor brick match can:
• •Result in a refusal of planning permission (if the officer or conservation officer considers the proposed material is too dissimilar to the existing property and the conservation area character)
• •Result in a planning enforcement notice requiring the external facing to be changed (if the extension is built in materials different from those approved in a materials condition or agreed in the planning permission)
• •Reduce the visual quality of the property in ways that affect value and future planning applications

**Conservation Area Character Appraisals and brick specifications**:

• Conservation Area Character Appraisals often contain specific guidance on appropriate and inappropriate materials for extensions in the conservation area. Common statements include:
• •'Extensions should be in matching or complementary London Stock Brick or similar soft mud yellow-buff brick'
• •'The use of modern machine-made red brick is inappropriate in this conservation area'
• •'Extensions should be faced in brick to match the existing dwelling, with mortar to match the colour and joint profile of the original brickwork'

LPAs may require a sample panel (a test panel of the proposed brick and mortar, built on site and approved by the LPA conservation officer before full construction commences) as a condition of planning permission. In conservation areas where the LPA is particularly strict, the planning condition may specify particular brick products by name (e.g., 'external brickwork shall match HG Matthews soft mud London Stock or equivalent product approved in writing by the Local Planning Authority').

**The sample panel process for London conservation area extensions**:

*What a sample panel is*: a small sample of the proposed brickwork — typically 1m² or larger — built on site (or sometimes at the contractor's yard if access is limited) using the proposed brick, mortar mix, and joint profile. The sample panel is inspected and approved (or rejected) by the LPA conservation officer before the main brick construction commences.

*Sample panel process*: 1. Planning condition specifies materials and requires a sample panel to be submitted and approved before commencement (or before external facing commences) 2. Contractor builds a sample panel of minimum 1m² (approximately 60 standard bricks) using the proposed brick and mortar mix 3. The sample panel is submitted to the LPA in a Discharge of Condition (DoC) application — including photographs and the brick/mortar specification 4. LPA conservation officer reviews the sample panel (typically by site visit to inspect the panel in situ) 5. LPA issues DoC approval (sample panel approved as the standard for the works) or requests modifications (different brick; different mortar colour; different joint profile) 6. Once the DoC is approved, construction can proceed to match the approved sample panel

*Time allowance for sample panel DoC*: 8 weeks from submission of the DoC application to LPA approval (the standard DoC determination period). In practice, conservation officer review can take 4–6 weeks — build this into the construction programme before the external brickwork commences.

**Practical briefing to the contractor for brick matching on a London extension**:

A written brief to the contractor should specify: 1. The required brick (manufacturer and product name; or 'reclaimed London stock matching sample from [supplier]') 2. The required mortar mix (cement:lime:sand ratio; or NHL lime mortar; specific sand colour) 3. The required joint profile (struck; flush; weathered; bucket-handle) 4. Whether a sample panel is required (and by when) 5. The planning condition reference for the materials approval (if applicable) 6. The requirement to match the coursing gauge of the existing brickwork (measure existing mortar joint thickness and brick dimension before ordering new bricks — this determines the target mortar joint thickness for the new work)

Without a clear written brief, a contractor may default to the cheapest available brick and standard grey OPC mortar — producing an obvious mismatch that is difficult and costly to remedy after the brickwork is complete.