Brick and Stone in Architecture 11/9/25
Passive House recap
Passive House standard aims to design buildings that are healthy, comfortable, and affordable, while requiring as little energy as practical and eliminating the performance gap between design intent and the constructed building. It targets translating proposed designs into real performance.
Five design basics (as highlighted in Elvira Berral's talk):
Orientation and form: the shape of the building; more compact shapes are more efficient; orientation relative to sun and wind matters.
Insulation: emphasis on continuous insulation to wrap the building shell.
Draught freeness / air tightness: minimizing unintended air leakage is crucial, especially in Wellington where drafts are an issue.
Windows and doors: insulation performance of openings; opportunities to improve insulation at these junctions.
Ventilation: cross-ventilation or mechanical ventilation; ensures indoor air quality and avoids overheating.
Continuous insulation: the insulation shell should be uninterrupted to minimize temperature differences across the building envelope, reducing moisture risk and heat loss/gain.
Continuous air or vapor control (vapor barrier): a continuous layer to prevent moisture/ water vapor from entering the structure. Usually placed on the inside of the structure to prevent moisture from inside (from occupants, cooking, showers, boiling kettles) from penetrating the wall.
Practical implications: design principles are good practice in general; aim to reduce the performance gap and improve overall building performance.
Earth and brick recap (recap of earth forms and brick fundamentals)
Earth materials come in two broad forms: unfired and fired.
Unfired earth: rammed earth, mud bricks, cob (clay/fiber composites that are compacted or piled).
Fired earth: tiles and bricks; terracotta tiles as fired clay products.
Adobe (a clay-rich earth brick) is a specific fired/earth product with a distinct clay composition.
Earthen materials can vary significantly in color and texture depending on the clay pit; this leads to a high degree of color differentiation in bricks and tiles.
Bricks and tiles are usually produced to near-standard sizes and can be locally manufactured near clay pits. They are strong in compression and durable, making them a common choice historically.
Terracotta: Italian for baked earth; a common fired brick/tile material.
Bricks are joined with mortar; bricks and tiles can form arches due to their compression strength. This leads to masonry construction, which is a simple technique of stacking masonry units (brick, stone, concrete blocks).
Masonry units are stacked; bonds connect the units; mortar binds them.
Mortar types:
Cement mortar: a mixture of sand, cement, and water; cement is a fine powder and provides the adhesive paste when mixed with sand and water. Cement is also used as an additive in concrete.
Lime mortar: uses sand, ground lime, and water; typically more breathable and less carbon-intensive than cement mortar.
Bricks: fired bricks have fire resistance and relatively uniform size (though not strictly standardized across all bricks). They are often produced locally; bricks are processed from crushed clay, ground, and formed into bricks; some bricks in the lecture are engineered bricks with internal cavities that provide insulation in addition to bonding.
Engineered bricks (e.g., Austrian-made bricks): extruded bricks with internal cavities that include insulation, providing both structural and insulating properties.
Special brick members: bricks can be molded for usability in window sills and jams to manage water flow, often called sills or jambs.
Bonding and nomenclature (brickwork terminology):
Bed joints: horizontal mortar joints between bricks.
Head joints: vertical joints between bricks.
A horizontal row is referred to as a course (the transcript uses the term “coarse,” which is likely a mispronunciation).
A vertical stack of bricks is a wythe (the transcript uses “white,” likely a mispronunciation).
A single brick’s components: bed (the bottom face), header (the brick’s end that is oriented toward the face of the wall), and stretcher (the brick’s face length).
Brick bonds (to lock layers and improve wall strength and aesthetics):
Running bond: all stretchers aligned in each course with continuous rows of bed joints; common for simple walls but leaves vertical mortar joints at each course.
Flemish bond: alternating headers and stretchers in each course, producing small vertical gaps and a distinctive pattern.
English bond: alternating courses of all headers and all stretchers; stronger against vertical cracking due to alternating courses.
Common bond: typically two or three courses of stretcher bonds followed by a course of headers; commonly used in the US.
The “header” in a course helps lock the wall together by tying courses.
The lecture emphasizes that many bonds aim to minimize vertical rows of mortar (weak points) by overlapping joints, which improves wall stability and durability.
Common growth patterns (visual patterns of bonds) vary; Flemish is common for aesthetic variation; running bond is common for speed; English and common bonds are used for structural strength and aesthetic variety.
Mortar layer thickness: a typical mortar layer should be around ; this is considered a sweet spot for mortar layers to avoid excessive mortar that can weaken the wall.
Cavity walls (introduced in the nineteenth century): a double-skin brick wall with a minimum air gap between two brick faces to manage moisture and ventilation. Two walls are connected by metal ties; the cavity allows moisture to disperse and be ventilated at the base through perforations in the mortar (reed poles).
Double shell walls (modern variation): the cavity is filled with insulation, creating a wall system with bricks (or brick-like insulation blocks) on the exterior and interior sides, with insulation in the middle. The outer brick skin can be decorative while the inner skin bears load, connected by ties.
Reasons for double-shell construction: aesthetic desire for brick on both faces, improved insulation, and reduced heat transfer while maintaining the look of a single material.
Notable example: Colombo Museum in Cologne by Peter Zumta (Zumta). The building uses handmade bricks to differentiate new construction from old site ruins, with brick screens stacked to control light and create atmosphere.
In New Zealand, masonry is often used as an infill or facade rather than for structural load-bearing purposes; aesthetics, cost, and reduced weight are additional reasons for using masonry with other structural systems (concrete/steel).
Masonry as façade element: bricks can form decorative curtain-wall façades (non-structural), such as the Tate Modern, where bricks coat the surface and are fixed to an underlying steel/concrete structure with anchors and insulation.
Robotics and AR in brick construction: research includes robotic bricklaying to improve efficiency and precision, as well as augmented reality (VR/AR) to plan and visualize brick stacking in the field.
Ceramic tiles as façade material: variations in ceramic tile profiles can be used on facades; tiles can be glued or mortared to walls; complex tile patterns are possible.
Amsterdam project: 3D-printed ceramic tiles used to mimic traditional Dutch row-house façades, enabling new patterns and textures while maintaining a tile-based system.
Stone: properties, types, and construction
Stone is a natural material, extremely strong in compression, durable, and inherently heavy and expensive to extract/transport.
Stone characteristics:
High compressive strength, limited tensile strength (not good in tension).
Each stone piece is unique with its own material properties.
Cold to the touch with high thermal conductivity and thermal mass, enabling significant heat transfer and storage.
Major rock types in architecture:
Igneous: formed from volcanic activity; very hard and durable (examples: granite, quartz, lava stone, and scoria).
Sedimentary: formed from sediment deposition and compaction; relatively softer and less durable (examples: sandstone, limestone).
Metamorphic: rocks altered by heat/pressure from other rocks; examples include marble and slate.
Quarrying and extraction: quarrying is an invasive, largely destructive process requiring heavy machinery; a granite quarry in Vermont is cited as an example to illustrate scale.
Local NZ examples: NZ Parliament Building uses Takaka marble from the Kairouro Quarry for columns/walls and Coromandel granite for steps/basement, demonstrating local material sourcing.
Stone in architecture: can be load-bearing (stone masonry) or used as cladding; stone masonry is similar in concept to brick masonry but uses irregular, non-standard natural blocks; making standard units from stone is more labor-intensive than with bricks.
Stone masonry types:
Rubble masonry: unsquared stones; very organic and varied in shape.
Random rubble: irregular courses without a clear pattern.
Coarse rubble: some horizontal courses formed through stacking.
Ashlar masonry: well-cut rectangular blocks; can be uniform or varying sizes; may be random ashlar or coarse ashlar.
Stone masonry without mortar (dry stone): stones fit together without cement; durable in some ancient examples (Inca walls) but generally vulnerable without joints.
Stone as cladding in modern architecture: often applied as a surface skin over a structural wall (concrete or masonry) with insulation layers behind it.
Notable examples of stone cladding and massing:
Ningbo Historic Museum (by Wang Xu): uses layered stone in a facade to reveal relics of old structures; involves a bearing concrete structure with an outer stone facade.
Oslo Opera House (by Snøhetta): stone panels form a uniform exterior skin; the building appears as a shell reaching into the sea, with a public plaza surrounding it.
Cistercian Abbey Church in Texas: massive limestone blocks (each about 2,300 kg) create a monumental massing; the design separates the roof from the wall to create a floating sensation.
Perelman Performing Arts Center (New York): stone can be monolithic and monumental, yet translucent when cut thinly; backlighting reveals the patterns of the individual stone pieces.
Contemporary research and fabrication: modern approaches include 3D printing or robotic-assisted brick/stone assembly; Gramazi & Kola (ETH Zurich) explored using a twisted/stacked wire-like reinforcement between stones to create a load-bearing, lightweight system that can be tested for structural capacity.
Stone as a cultural and sustainable material: emphasizes understanding intrinsic properties, climate, culture, and sustainability; encourages poetic and design exploration while respecting traditional craftsmanship.
Detailed notes on stone and brick details
Stone masonry details (examples in the talk):
Steel structural walls with stone cladding; mortar bed; marble sheets fixed with metal clamps to create a uniform surface.
A modern massing example demonstrates the massiveness of stone with a clean, monolithic surface.
Notable mass and size: the Cistercian Abbey Church uses enormous limestone blocks; each block weighs approximately .
The thermal and acoustic qualities of stone surfaces can contribute to interior atmosphere, especially when used in large, grand spaces.
The use of stone for load-bearing and cladding invites a conversation about structural integration: often, modern buildings decouple the structural system from the stone veneer to optimize weight, insulation, and performance.
Connections to broader themes and implications
Material choice reflects a balance of aesthetics, performance, cost, and sustainability; brick and stone offer different capabilities for structure, enclosure, and facade expression.
The discussion acknowledges that masonry is not purely a structural decision; it heavily influences the look, texture, and historical continuity of a building.
The use of masonry can be strategic for cultural storytelling (e.g., Zumta’s Colombo Museum reuse of old ruins with new bricks) and for contextualized design (local materials, local patterns).
Modern techniques (robotics, AR, 3D-printed tiles) suggest a future where brick and stone can be produced and assembled with higher precision and novel patterns, expanding the range of possibilities while retaining traditional material logics.
Practical takeaways for practice and exams
Understand the differences between brick types (fired vs unfired), brick bonds, and the practical implications of bond choice on wall strength and weatherproofing.
Recognize the role of mortar and its thickness as a critical factor in wall performance and durability.
Be able to explain cavity walls and double-shell walls, including their purposes (moisture management, insulation, aesthetics).
Know the key stone categories (igneous, sedimentary, metamorphic) and their typical architectural uses, advantages, and limitations.
Distinguish between stone masonry types (rubble vs ashlar) and the implications for texture, construction complexity, and appearance.
Understand how stone can function as both load-bearing and cladding, and how modern practice often pairs stone with other structural systems.
Be aware of how contemporary technologies (robotics, AR, 3D-printed elements) are shaping masonry practice.
Reflect on ethical, cultural, climate, and sustainability considerations when selecting masonry materials and detailing; consider how design can honor local craft traditions while exploring new performance potentials.