The Interior Design Course: Principles, Practices, and Techniques

Principles and Foundation of Interior Design

• Interior design is fundamentally a social activity that brings people together, facilitates effective communication of ideas, and allows the creative sharing of interests.
• The discipline transforms lives by making intangible spatial qualities real and tangible within immediate environments.
• The course structure mirrors a top design college curriculum, organized into self-contained two-page or four-page tutorial units covering theoretical, creative, technical, and professional topics.
• Core components of the curriculum include:
  • Tutorial units covering theoretical and practical concepts.
  • Set projects to test skills continuously.
  • Student examples to benchmark peer work.
  • Specially commissioned step-by-step photographed sequences for model making and technical drawing.
  • Professional case studies detailing practical briefs, budgets, and real-world execution.
  • Back-of-book resources including a comprehensive glossary, resource directory, and bibliography.

Chapter 1: Concept Development

Unit 01: Site Research and Building Study

• Research provides the fundamental context for understanding architectural sites, increasing knowledge, and discovering design solutions beyond simple problem-solving.
• Buildings embody personalities, values, beliefs, and qualities that must be observed and tapped into.
• The Project Guidelines:
  • Select an accessible building of interest.
  • Study its geometry, form, scale, proportions, details, materials, and functions.
  • Visualize the structure as a collection of horizontal and vertical planes.
  • Utilize cameras to document overall views, close-up details, and material textures.
• Timed Sketches:
  • Five-minute sketches: Expressive, lively drawings capturing core ideas and main features quickly using soft pencils or charcoal.
  • Detailed drawings: Time-intensive drawings providing accurate, detailed structural information using hard pencils ($2\text{H}$ or $4\text{H}$) for line control or ink for fine detailing.
• Site Considerations & Site Forces:
  • Observe how the building sits within the street and its relationship to surrounding architecture.
  • Evaluate external site forces such as adjacent busy roads, rivers, parks, or markets.
  • Use aerial perspectives with circulation arrows to establish relationships between public and private spaces.
• Architectural Research Checklist:
  • Solids and Cavities: Study overall geometry, including facades, doors, and window openings.
  • Scale and Proportion: Assess internal scale and proportion relative to the surrounding context.
  • Rhythm: Identify repetitions, ornamental details, or lines suggesting movement.
  • Texture: Investigate material usage and contrast.
  • Light and Shade: Document light patterns that enhance or alter design elements.
  • Colour: Explore applied and natural colours and their interior/exterior impacts.
• Documentation Methods:
  • Compile structured notes, photographs, perspective sketches, and diagrams in a working sketchbook.
  • Use spider diagrams for brainstorming initial architectural, social, or cultural themes.
  • Case Example (Privileged Nomadism): A London apartment shared by a brother and sister living as privileged nomads, featuring separate entrances ("his entrance" and "her entrance"), adaptable spaces, and minimal possessions for transient occupancy.

Unit 02: Building a Sketchbook

• A sketchbook is a personal, unique journal and an archive of mental processes, design influences, and visual references.
• It functions as an informal working tool to test ideas, record research chronologically, and document decision-making without fear of initial errors or strict critical judgement.
• Sketchbook Components:
  • Spatial Diagrams: Early line drawings, perspective sketches, and visual representations of spatial journeys.
  • References: Detailed project research, articles, case studies, and reference models.
  • Illustrations & Collages: Found imagery, layered pictures, and collages exploring texture, colour, mood, and immediate material relationships.
  • Design Criteria: Sets of prioritized rules, qualities, and essential ideas generated to guide design choices.
• Sketchbook Deconstruction Project:
  • Stage 1: Select site research drawings and photographs; photocopy and enlarge key structural fragments (window facades, stairs, doors, junctions).
  • Stage 2: Deconstruct geometries down to bare lines or planes; combine fragments and overlay collages using varied media to depict form, shape, texture, and color.

Unit 03: Making a Sketch Model

• Sketch models provide a quick, expressive, three-dimensional method to explore spatial scale, light, texture, and form.
• Modelling prioritizes loose, ambiguous spatial exploration over realistic finishes.
• Essential Model-Making Equipment:
  • Utility Knife: Sturdy metal handle for heavy-duty cutting through thick board, wood, and sheet metal.
  • Scalpel: Lightweight, extremely sharp knife for precise cuts, small details, and curves.
  • Plastic-Cutting Blade: Specialized blade for scoring and cutting acrylics and plastics.
  • Cutting Mat: Protective, self-healing surface for safe cutting.
  • Rulers & Squares: Non-slip steel ruler (backed with masking tape) as the primary cutting edge; engineering or T-square ($100\text{ mm}$ / $4\text{ in}$) for right-angled cuts and alignment.
  • Adhesives & Fixings: White Polyvinyl Acetate (PVA) glue for paper/card edge-to-face joints; balsa cement for wood-to-wood; specialized acrylic solvent for acrylics; hot glue gun for messy, quick structural joints (metals); spray glue for paper/card mounting in well-ventilated areas; straight pins for supporting setting joints.
• Modelling Materials:
  • Card stock, foam board, balsa wood, sheet metal, tracing paper, acrylic, wire.
• Project Execution:
  • Select an architectural fragment from sketchbook research (e.g., refracted light walkway).
  • Construct a structural framework (Stage 1), apply clad/slotted surface textures (Stage 2), and analyze/adjust spatial qualities (Stage 3).
  • Produce a sequence of 3–4 sketch models exploring contrasting materials, colours, and textures.
  • Document and photograph models against dark backgrounds from human eye-level perspectives.

Unit 04: Developing an Idea

• Idea generation requires keeping the design process open, fluid, and intuitive without rushing to premature conclusions.
• Sources of inspiration include paintings, literature, physical objects, evocative memories, or abstract concepts.
• Concept Board Development Project:
  • Select 5 evocative words; research their exact dictionary definitions.
  • Stage 1: Brainstorm word associations using visual spider diagrams.
  • Stage 2: Source specific, abstract, architectural, and atmospheric images representing these words.
  • Stage 3: Juxtapose selected words and images on an $C$ ($17 \times 22\text{ in}$) or international $\text{A2}$ ($16.54 \times 23.39\text{ in}$) board using spray adhesive.
  • Stage 4: Formally present the concept board to peers/clients for feedback.

Case Study 01: Modern Restaurant (ARTEC)

• Brief: Redesign an empty metropolitan shell into a modern Italian restaurant accommodating 48 diners on a good-to-moderate budget. Food quality is the primary design driver.
• Design Strategy & Stages:
  • Stage 1 (Brainstorming): Derived key concept words from menu dishes: Modern, Balanced, Farmhouse, Warm, Rustic, Simple, Intimate, Earthy, Style, Honest, Cozy, Clean.
  • Stage 2 (Concept Board): Presented collaged tearsheets, magazine images, and light fitting photos to convey a "modern rustic" atmosphere.
  • Stage 3 (Preliminary Sketch): Produced rapid, energetic freehand perspective sketches on-site for the unpaid client pitch.
  • Stage 4 (Presentation Perspective): Rendered scale perspectives displaying exact materials, custom furniture, slate, stone, wood, and ambient mood lighting.
  • Stage 5 (Floor Plan): Created CAD scale floor plans showing complete furniture arrangements, circulation routes, light sources, and washroom details.

Case Study 02: Interior to Exterior (Fieldhouse Associates)

• Brief: Add a kitchen/dining extension with doors opening to a garden for a professional couple interested in 1930s and 1950s Art Deco architecture on a small budget.
• Execution Details:
  • Constructed a micro-building featuring a copper roof designed to weather over time from dull brown to a lustrous green patination.
  • Installed a curved glass, steel-framed bay window to wrap around a custom interior seating area.
  • Designed bespoke banquette seating with muted soft leather upholstery and shiny aluminium accents, directly referencing streamlined Art Deco styles.
  • Separated functional utility kitchen spaces from garden relaxation areas for smooth spatial circulation.

Chapter 2: Design Realization

Unit 05: Drawing Materials

• Paper Types:
  • Typo Detail Paper: Inexpensive, highly transparent paper for sketching, layout planning, and field survey notes.
  • Tracing Paper: Expensive paper reserved for final presentation drawings. Standard weights: $28\text{ lb}$ (general purpose) and $42\text{ lb}$ (high quality).
• Pencils & Lead Holders:
  • Wooden Lead Pencils: Sharpened with a blade for superior line quality. Hard leads ($4\text{H}$, $2\text{H}$) give precise control for medium-to-hard lines; $F$ or $H$ leads are used for finished drawings and lettering; soft leads ($HB$) create bold lines but smear easily.
  • Lead Holder Pencil: Requires skill; line weights are varied by pulling and rotating the pencil simultaneously. Always pull lines (bottom-to-top, left-to-right); never push.
  • Mechanical Clutch Pencil: Uses fixed lead diameters ($0.3\text{ mm}$, $0.5\text{ mm}$, $0.7\text{ mm}$, $0.9\text{ mm}$) providing consistent line width without sharpening.
• Technical Drawing Equipment:
  • Technical Pens: Precision ink pens with tubular metal nibs (widths: $0.18\text{ mm}$, $0.25\text{ mm}$, $0.3\text{ mm}$, $0.5\text{ mm}$). Stored nib-upward; work left-to-right and top-to-bottom.
  • Drawing Board & Parallel Motion: Drafting table equipped with a straight-edge parallel motion bar for true horizontal parallel lines. Cleaned using lighter fluid or mild cleansers.
  • Adjustable Set Square: Large $300\text{ mm}$ ($12\text{ in}$) acrylic triangle with bevelled edge used against the parallel motion for vertical ($90^\text{o}$) and angled lines.
  • Scale Ruler: Triangular ruler for metric scale conversions ($1:5$, $1:10$, $1:20$, $1:50$, $1:100$). All dimensions must be noted in millimetres ($\text{mm}$) or metres ($\text{m}$).
  • Curves & Templates: Circle templates for small circles/arches; compasses for large ink circles; acrylic French curves and rubber flexi-curves for organic shapes.
  • Erasers & Accessories: White erasers for pencil; putty erasers for tidying; plastic erasers/scalpels for ink scraping; eraser shields for precise deletion; drafting brushes for debris removal.

Unit 06: Human Dimensions

• Scale, Ergonomics, and Proportion:
  • Scale: Perception of spatial dimensions relative to human size. Dominant or oversized spaces (churches, skyscrapers) evoke awe or intimidation.
  • Proportion: Mathematical and geometric ratio systems that establish visual harmony, balance, and visual relationships regardless of absolute size.
  • Ergonomics: The science of designing spaces, furniture, and products to fit human physical dimensions, movement, comfort, and operational needs.
• Human Body Proportions:
  • The standard human body is measured as 7 equal units, with the head representing $\frac{1}{7}\text{th}$ of total height.
  • Standard standing eye level is approximated at $1,500\text{ mm}$ ($5\text{ ft}$).
• Ergonomic Design Examples:
  • Paperclip: Simple, functional, stays flat.
  • Hard Hat: Safety headgear designed for construction environments.
  • Spectacle Frames: Tailored to fit facial contours comfortably.
  • Supermarket Trolley: Stackable, high-capacity retail tool.
  • Swiss Army Knife: Compact, housing multiple miniature functional tools.
  • Frying Pan: Heat-conducting body paired with a heat-resistant handle.
  • Suitcase: Hardwearing, load-bearing with latches and handles.

Unit 07: Architectural Drawing Conventions

• Orthographic Projection (2D Drawings):
  • Plan: A horizontal cross-section taken through a building at waist height—$1,200\text{ mm}$ ($4\text{ ft}$)—with the upper section removed. Shows room layouts, wall thicknesses, door swings ($90^\text{o}$ angle), window locations, and stairs. Overhead features (beams, mezzanines, skylights) are depicted with dotted lines.
  • Elevation: An un-cut vertical view displaying the exterior facade, doors, windows, and architectural details.
  • Section: A vertical cut through the length (long section) or width (short section) of a building. Discloses internal spaces, floor levels, staircases, and ceiling heights. Structural cut points are drawn with heavy lines.
• Drawing Standards and Conventions:
  • Line Weights:
    • Heavy ($0.5\text{ mm}$, $0.7\text{ mm}$, $0.8\text{ mm}$, $1.0\text{ mm}$): Outlines, structural walls, and primary cut-through points.
    • Medium ($0.25\text{ mm}$, $0.35\text{ mm}$): Non-structural elements, doors, stair treads, and furniture.
    • Fine ($0.1\text{ mm}$, $0.18\text{ mm}$): Surface details, tile patterns, floorboard lines, glass, and door swings.
  • Section Arrows & Scale Bars: Section cut locations are indicated outside the plan boundary using numbered arrowheads showing view direction. Scale bars ensure accurate dimension reading if drawings are resized.

Unit 08: Survey and Freehand Drawing

• Surveying Equipment:
  • $30\text{-yard}$ tape measure, pocket tape measure, folding rod, carpenter's rule (for pitches/angles), ledger-size vellum paper pad, pencils, camera, compass (for North point).
• Step-by-Step Survey Procedure:
  • Stage 1: Obtain existing historical or planning drawings to use as preliminary references.
  • Stage 2: Schedule a site visit; allocate at least a half-day ($0.5\text{ day}$) for thorough access.
  • Stage 3: Walk through the site to note spatial proportions and physical obstructions.
  • Stage 4: Prepare freehand field sketches. Pace out length-to-width ratios, draw structural walls, indicate door/window openings, overhead beams (long dashes for overhead, short dashes for hidden lower elements), floorboard direction, and the North point.
  • Stage 5: Draw dimension lines outside the plan layout. Work systematically in a clockwise direction.
  • Stage 6: Execute measured running dimensions with two people (one holding zero-end, one calling out measurements). Running dimensions originate from a single corner point continuously down a wall to eliminate cumulative additions. Record wall recess depths and diagonal measurements across non-square rooms.

Unit 09: Technical Drawing

• Drafting Sequence for Plans:
  • Stage 1: Tape tracing paper onto the drawing board. Lay out light pencil construction lines for main spatial outlines using the parallel motion bar and set square.
  • Stage 2: Draw heavy lines over construction lines to establish structural wall thickness, columns, and pillars.
  • Stage 3: Carve out wall openings for doors, windows, fireplaces, and stairs.
  • Stage 4: Add intermediate line weights for non-structural partitions, doors, and furniture. Add fine line weights for tile patterns, floorboards, and glass.
  • Stage 5: In-fill structural cut walls with solid ink or hatching (pouche) for high contrast, and finalize pencil draft with ink tracing pens.
  • Stage 6: Project vertical guidelines directly from the completed plan to construct corresponding section drawings.

Unit 10: Making Presentation Models

• Model Construction Specifications:
  • Base Plate: Construct on flat Medium-Density Fibreboard (MDF) to prevent warping ($6\text{ mm}$ / $\frac{1}{4}\text{ in}$ MDF for $100\text{ mm}$ square models; $12\text{ mm}$ / $\frac{1}{2}\text{ in}$ MDF for $600\text{ mm}$ square models).
  • Base Finish: Mount pre-cut floor finish papers or wood veneers using spray adhesive or impact adhesive applied to both surfaces. Prick plan layout coordinates through tracing paper onto the base plate using a scalpel tip.
  • Wall Fabrication: Use foam board, heavy card, balsa wood, or acrylic. Cover materials in advance with self-coloured papers (colors appear paler at model scale due to aerial perspective).
  • Concealed Butt Joints (Rabbets): Cut through top skin and polystyrene foam core of foam board using a scalpel; peel foam away from bottom paper skin to form a clean overlapping corner joint.
  • Curved Walls: Score a series of equally spaced parallel slices through the outer paper skin and foam layer; bend carefully and cover with paper using spray glue.
  • Wall Assembly: Glue walls sequentially directly onto the baseplate with PVA; maintain true vertical $90^\text{o}$ alignment using engineering squares while drying.
  • Windows: Execute sandwich construction. Cut identical window openings in an inner card wall and outer card wall. Sandwich a full-length sheet of clear acetate or $1\text{ mm}$ acrylic between them using double-sided tape.
  • Staircases: Build a pair-of-strings card jig to align treads and risers. For cantilever stairs, hold steps in the jig until glued. For spiral stairs, draw plan circles on card, mount steps onto a horizontal newel jig with a bird's-mouth joint using balsa cement, and rotate as each step sets.
  • Model Landscape & Detail Features: Trees spun from fine wire; cliffs/rocks made from florist cork bark; water depicted using dark shiny paper, varnish, or acrylic sheet.
  • Photography: Photograph models at exact scaled eye levels using natural or artificial lighting, wide-angle lenses, and high-contrast black-and-white or colour film.

Unit 11: Axonometric and Perspective Drawing

• Axonometric Drawing:
  • Orthographic 3D projection showing true plan, section, and elevation in one single view.
  • Orientations: Plan lines rotated to $45^\text{o}/45^\text{o}$, $60^\text{o}/30^\text{o}$, or $90^\text{o}$ angles to the horizontal (totaling $90^\text{o}$).
  • Step-by-Step: Mount true plan at chosen angle; overlay tracing paper; project vertical heights straight up from plan points using set square and scale ruler; ink using varying line weights.
• Perspective Drawing:
  • Realistic 3D visual depicting exact spatial views from a specific human viewpoint and eye level.
  • Setup: Position true plan at top of board and selected elevation below it.
  • Eye Level: Standard standing eye level drawn at $1.5\text{ m}$ ($5\text{ ft}$); lower for seated views (exposing ceilings); higher for bird's-eye views (exposing floor layouts).
  • Vanishing Point (VP): Formed by extending the viewer's position line vertically to intersect the eye-level line.
  • Cone of Vision: Set at $60^\text{o}$ total ($30^\text{o}$ on each side of central viewer line). Objects outside this cone suffer visual distortion.
  • Depth Construction: Establish a Measuring Line by transferring viewer-to-wall distance horizontally from the elevation. Connect Measuring Line to eye level to mark the Measuring Point (MP). Project width, height, and depth points to VP and MP.

Unit 12: Computer-Aided Design (CAD)

• Role and Function:
  • CAD software operates as a drafting, modelling, calculations, and spatial simulation tool, allowing designers to test complex form, lighting, economic, and environmental criteria.
• CAD System Elements:
  • 2D Objects: Lines (variable thickness, color, styles, arrowheads), arcs, circles, polygons, planar shapes, structural symbol grids.
  • 3D Objects: 2D planar shapes extruded upward into 3D walls, floors, or roofs; predefined 3D volumes; wire-frame rotations; animated walk-through simulations.
• Software Categories:
  • Professional Programs: AutoCAD (industry standard for construction/drafting), Microstation (architectural), Vectorworks (design/technical).
  • Domestic / Entry-Level Software: SmartDraw, 3Dspacer (simple layout tools pre-loaded with furniture/fixture libraries).

Case Study 03: Flexible Space (Brook Fieldhouse Associates)

• Brief: Remodel a two-bedroom riverside flat into a flexible home studio/office for a home-working designer.
• Design Solution:
  • Incorporated built-in storage exceeding $15\text{\%}$ of total flat volume, with $75\text{\%}$ hidden behind closed panels.
  • Removed a non-structural stud partition wall between the second bedroom and sitting area; replaced it with three sliding partition panels to establish an $\text{L-shaped}$ open floor plan $6\text{ m}$ ($20\text{ ft}$) wide.
  • Integrated a fold-down wall bed, allowing the studio office space to convert into a second bedroom at night.
  • Replaced patio doors with folding glass panels to connect interior spaces to riverside views.
  • Installed backlit wall panels raised off the floor and ambient wall lighting (removing central ceiling fixtures).

Case Study 04: Updating the Dated (Forster, Inc.)

• Brief: Transform a small, dated penthouse bathroom into a luxurious, glowing light feature on a small budget.
• Design Solution:
  • Extended bathroom footprint into a large hallway using a semi-circular curved wall feature.
  • Constructed curved wall from a laser-cut stainless steel frame clad in a double skin of translucent polypropylene and transparent acrylic.
  • Inserted orange and yellow coloured film panels inside the wall frame, illuminated at the base by dimmable neon tube lights.
  • Finished floor with cool blue glass mosaic tiles contrasting with blue walls; concealed exposed bath plumbing with custom stainless steel detail plates.

Chapter 3: Design Projects

Unit 13: Creating a Brief

• A brief defines the project scope, parameters, aims, and restrictions, organizing design tasks into structured phases.
• Three Project Stages:
  • Stage 1 (Evaluation): Site analysis, data gathering, identifying inherited fixed restrictions ("givens").
  • Stage 2 (Analysis): Evaluating client requirements, lifestyle needs, practical and impractical desires.
  • Stage 3 (Synthesis): Integrating conceptual ideas, physical realities, legal constraints, and financial limits into a clear design scheme.

Unit 14: Writing a Client Profile

• Designers must interpret true underlying user requirements, which often differ from what non-designer clients explicitly ask for.
• Maintain structured communication, record meeting notes, and obtain written client signatures for all specification revisions.
• Client Profile Criteria:
  • Age, gender, occupation, economic status, lifestyle values, hobbies, and family dynamics.
• Commercial Checklist Requirements:
  • Evaluate corporate branding/logo integration, staff hierarchy, user spatial requirements, work patterns, and work schedules.

Unit 15: Writing a Design Proposal

• A design proposal is a written strategy and mission statement outlining how the interior scheme will meet brief criteria.
• Proposal Section Structure:
  • Location & Site Description: Contextual factors, site research, structural findings.
  • Brief Analysis: Client requirements converted into concrete design criteria.
  • Design Concept & Strategy: Phased explanations of proposed spatial modifications accompanied by diagrams, freehand sketches, and technical drawings.
• Checklist Execution:
  • List existing elements to keep, elements to strip out/remove, and new architectural elements to introduce.

Unit 16: Planning Your Design

• Spatial Planning Tools:
  • Bubble Diagrams: Abstract spatial diagrams using varied bubble sizes and connecting paths to map spatial hierarchy, functional zone ratios, and circulation paths.
  • Sketch Elevation & Section Drawings: Testing ceiling adjustments, raised platforms, and stair approaches.
• Project Realization Workflow:
  • Stage 1: Execute site survey and build a $1:20$ or $1:50$ scale card model.
  • Stage 2: Plan spatial layout based on client profile, positioning plumbing/electrical services and maximizing natural light.
  • Stage 3: Produce rendered scale final plans, axonometrics/perspectives, and a physical sample board of specified finishes.

Case Study 05: Retail Shop (Forster, Inc.)

• Brief: Create a directional interior showcase for contemporary fashion garments in a boutique retail shop on a small budget.
• Design Strategy:
  • Treated the interior as a stark white-cube gallery.
  • Custom-built garment display trees made from floor-to-ceiling powder-coated steel tubes, each featuring 3 hanging tiers.
  • Mounted full-length wall mirrors behind display trees to create an optical illusion of a floating fashion forest.
  • Designed a flexible, modular cashier station built from white-sprayed fibreboard topped with white laminate.
  • Varied interior white textures: tongue-and-groove timber cladding on one wall, smooth white plaster on others, white shag-pile rug over a softwood stockroom partition, hospital curtain rails for fitting rooms, and a white polished concrete floor.

Case Study 06: Coffee House (Forster, Inc.)

• Brief: Create a brand identity and interior scheme for a coffee house chain located within a raw, industrial double-height urban shell on a small-to-medium budget.
• Design Strategy:
  • Retained raw industrial elements: exposed breeze blocks, distressed peeling paint, and unpolished concrete.
  • Created eclectic seating combining second-hand sofas, chairs, and custom $25\text{ mm}$ ($1\text{ in}$) plywood tables topped with striped coloured laminates.
  • Fabricated steel star ceiling frames suspending custom lampshades constructed from actual coffee cups.
  • Constructed a central cast-concrete service bar counter topped with solid walnut block-work.

Chapter 4: Building Construction

Unit 17: Building Components

• Floors:
  • Horizontal load-bearing planes carrying live loads (people, moveable furniture) and dead loads (weight of structural materials).
  • Timber floors use linear joists laid on their short sides; concrete floors utilize in-situ poured concrete or precast planks on steel joists.
• Walls:
  • Vertical planes providing separation, thermal insulation, and acoustic attenuation.
  • Load-bearing walls: Support upper structural weights.
  • Partition stud walls: Non-structural timber/metal frameworks clad in drywall/plasterboard, housing electrical conduit and insulation.
• Windows & Doors:
  • Windows: Fixed, casement, sliding, double-hung sash, or pivoting frames made of wood, aluminium, or steel.
  • Doors: Panel, sash, louver, French, glass panel swinging, sliding, folding, revolving, or pivoting doors. Fire-resistance ratings range from 30 minutes to 4 hours.
• Stairs:
  • Vertical circulation systems (straight-run, $\text{L-shaped}$, curved, spiral, winding, $180^\text{o}$ return $\text{U-shaped}$) requiring safety balustrades and landing spaces equal to stair widths.
• Material Surface Finishes:
  • Wood: Ash (oiled), Maple (lacquered/unfinished), Olive ash, Cherry (oiled), American elm, Yellow pine, Red oak (oiled), Yew, Siberian larch.
  • Concrete: Acid-etched, polished plaster, moulded, combed.
  • Stone: Grisdevilette limestone (acid-washed), Lunel (polished), Frog eye limestone, Broughton Moor slate (sanded), Marron Emperador limestone, Blue marble, Blue Savoy marble, Brown marble.
  • Metal: Stainless steel (relief, stripe, red/blue embossed, square relief), flexible wire weave, chunky woven bars.

Unit 18: Building Materials

• Structural Mechanics:
  • Tension: Natural pulling/stretching force that lengthens a structural member.
  • Compression: Natural pushing/squeezing force that shortens a structural member.
  • Strength/Weight Ratio: Structural efficiency calculated by comparing material load capacity against self-weight.
• Material Properties:
  • Wood: Softwoods (pine, spruce) are cheap and quick-growing; hardwoods (oak, mahogany, teak, iroko) are dense and durable. Wood has high strength/weight stiffness but must be certified by the Forest Stewardship Council (FSC) for sustainability.
  • Glass: Toughened or laminated glass used for partitions, floors, stairs, and doors. Finishes include acid-etching, sandblasting, frosting, enamelling, laminating, and tinting.
  • Steel: Structural alloy of iron and carbon; adding nickel produces rust-proof stainless steel. High strength/weight ratio makes it ideal for beams, columns, and suspension cables, though it requires fireproofing and anti-corrosion coatings.
  • Concrete: Mixture of cement, sand, stone aggregates, and water. Reinforced concrete incorporates internal steel bars/mesh to handle tensile forces.
• Green Design Principles:
  • Maximize solar heat gain, reduce excessive glazing, specify low embodied-energy materials, implement grey-water recycling systems, and install low-volume dual-flush WC cisterns.

Unit 19: Services

• Water Supply & Drainage:
  • Water is sourced from reservoirs or underground wells, filtered, chlorinated, and chemically softened.
  • Distributed via pressure head through street mains to internal storage cisterns.
  • Appliance waste and toilet soil discharge into lateral branch runs, down vertical collecting stacks, to underground sewers.
• Electricity Supply:
  • Enters underground to a mains fuse box and distributes across isolated sub-circuits (heavily-loaded appliance circuits vs lightly-loaded lighting circuits).
  • Earthing wires protect users; bathroom switches must use external wall switches or internal insulating pull-cords.
• Gas Supply:
  • Mains natural gas passes through an entry stopcock, pressure governor, and meter.
  • Distributed internally via $25\text{ mm}$ ($1\text{ in}$) copper pipes reducing to $15\text{ mm}$ ($rac{1}{2} ext{ in}). Pipes must never pass through bedrooms or unventilated wall voids.\n* **HVAC (Heating, Ventilation, and Air Conditioning)**:\n * Central heating uses boilers to circulate heated water through pipe networks to radiators.\n * Mechanical ventilation draws in fresh air, extracts stale air via fans through networks of ducts, and incorporates heat-recovery systems.\n\n## Unit 20: Lighting\n\n* **Lighting Metrics & Properties**:\n * *Lux*: Standard unit measuring light quantity/illuminance level within a space.\n * *Color Rendering*: The capacity of a light source to reveal surface colors accurately compared to natural daylight.\n * *Surface Reflectance*: Light surface colors reflect light and raise ambient illumination; dark surfaces absorb light.\n* **Lamp Types**:\n * *Incandescent*: Filament glows when heated; provides warm color temperature and full spectrum rendering, but has low energy efficiency and short life.\n * *Fluorescent*: Phosphor coating inside tube reacts to electric current; highly efficient with variable color rendering.\n * *Halogen*: Incandescent variant containing iodine/bromide gas. Low-voltage (12 ext{-volt}$) halogen lamps feature thick filaments producing intense light compared to$240 ext{-volt} versions.\n * *High-Intensity Discharge (HID)*: Current passes through gas vapors (low-pressure sodium for yellow street lights; high-pressure mercury for white light).\n * *LEDs & Fibre Optics*: Maintenance-free, cool-to-touch lighting sources driven by low current or magnetic fields.\n\n## Unit 21: Colour and Interiors\n\n* **Colour Theory Basics**:\n * *Primary Colours*: Red, Yellow, Blue.\n * *Secondary Colours*: Orange (Red + Yellow), Green (Yellow + Blue), Violet (Blue + Red).\n * *Tertiary Colours*: Red-Orange, Blue-Green, etc.\n * *Hue*: The identity of a specific color along the spectrum.\n * *Value (Tone)*: The relative lightness (high value/tint) or darkness (low value/shade) of a color from white to black.\n * *Chroma (Saturation/Intensity)*: The purity or strength of a hue relative to neutral grey.\n* **Colour Harmonies**:\n * *Monochrome*: Single-hue color scheme utilizing varied values and chromas.\n * *Contrast*: Incorporates small accent pops of complementary colors opposite on the color wheel.\n * *Complementary*: High-contrast schemes pairing opposite wheel colors (e.g., Red vs Green, Violet vs Yellow).\n* **The Munsell Colour System**:\n * Albert Munsell's notation system categorizing color along 3 dimensions:\n 1. *Hue*: Measured around a 10-hue horizontal circle (5 principal hues: Red, Yellow, Green, Blue, Purple; plus 5 intermediate hues).\n 2. *Value*: Measured along a vertical pole divided into 10 steps from Black (0$) at the base to White ($10) at the top.\n 3. *Chroma*: Measured horizontally outward from the vertical grey axis, showing saturation strength steps.\n\n## Unit 22: Textiles and Fabrics\n\n* **Natural & Mixed Fibres**:\n * Cotton, silk, wool, linen. Blends enhance durability (e.g., wool/nylon, silk/cotton, cotton/viscose).\n* **Utility Fabrics**:\n * Heavy woven cottons, denim, canvas, hemp, hessian, jute, jacquard, ripstop, Teflon-coated fabrics, and Tyvek.\n * Rated commercially using mechanical rub tests measuring abrasion resistance.\n* **Luxury Fabrics**:\n * Raw silk, velvet, chenille, wool mohair, silk voile, organza, gold quilt, metal silk, ottoman, jumbo corduroy, handwoven silk, and silk taffeta.\n* **Sheers & Modern Synthetics**:\n * Lace, laser-cut fabrics, raffia sheers, felt appliqué, organza.\n * Synthetic fibres: Acrylic, viscose, polyester (stain-resistant, fire-retardant, and durable).\n\n## Unit 23: Creating a Directory\n\n* **Directory Filing System**:\n * *Address Book*: Categorized index listing supplier contacts across flooring, lighting, carpentry, paints, soft furnishings, and electrical goods.\n * *Product Literature*: Lever-arch binders organizing trade catalogues.\n * *Samples*: Box files containing fabric, laminate, metal, stone, and timber physical samples.\n * *Trade Magazines*: Indexed files housing industry journals for aesthetic references.\n\n## Unit 24: Writing a Specification\n\n* A specification forms a legal contract binding the designer, client, and contractor.\n* **Specification Drafting Phases**:\n * *Stage 1*: Divide project by rooms and trade headings (strip out, scope of work, services, finishes, joinery, decoration, electrical).\n * *Stage 2*: Specify individual trade responsibilities.\n * *Stage 3*: Include standard mandatory header clauses:\n * "All work is to be carried out to appropriate standards in accordance with ICC and local standards."\n * "Contractor to advise on schedule and discuss with supervising officer..."\n * "Contractor's responsibility to ensure site safety, security, and cleanliness..."\n * "Do not scale drawings. All dimensions to be checked on site."\n\n## Unit 25: Creating a Sample Board\n\n* Sample boards assemble physical materials, finishes, furniture tearsheets, and lighting specs onto a single presentation board.\n* **Presentation Styles**:\n * *Pure Samples*: Minimalist board featuring unadorned material swatches.\n * *Impressionistic Presentation*: Creative montage mixing photographs, drawings, and swatches.\n * *Linear Presentation*: Structured grid lining up samples alongside descriptive labels.\n\n## Case Study 07: Large-Scale Residence (Forster, Inc.)\n\n* **Brief**: Expand storage solutions for a city banker's 3.3 ext{ m}$($11 ext{ ft}) high warehouse apartment accommodated for two residents.\n* **Design Solution**:\n * Built two massive floor-to-ceiling floor-standing wedge storage units made from rac{3}{4} ext{ in}$($18 ext{ mm}) Medium-Density Fibreboard (MDF) clad in American black walnut veneer and cream plastic laminates.\n * Fitted wedge units with bottom yellow dimmable fluorescent strip lighting to make the mass float off the floor.\n * Fabricated custom entertainment furniture boxes (drink box, TV box, sound system box) built from Buffalo board (truck-lining plywood) featuring acrylic Prada-esque corner tabs, stainless steel push latches, and magnetic fittings.\n\n## Case Study 08: Living as an Event (Procter-Rihl)\n\n* **Brief**: Build a contemporary residence ("Slice House") on a narrow urban corner site for a history lecturer, focusing on spatial luxury over expensive materials.\n* **Design Solution**:\n * Designed tilting, folding walls and forced perspective corridors (sloping ceiling height down to 1.8 ext{ m}$/$6 ext{ ft}).\n * Constructed a continuous 7 ext{ m}$($23 ext{ ft}$) folded steel plate kitchen counter featuring$2 ext{ m}$($6 ext{ ft } 6 ext{ in}) cantilevered floating ends serving as dining and courtyard tables, incorporating an integrated triangular stainless steel sink.\n * Built an upper-floor glass-tank swimming pool suspended over the lower living space, acting as an ambient light filter during the day and a glowing coloured light fitting at night.\n * Fabricated a ext{U-shaped}$stair constructed from an$8 ext{ mm}$($\frac{5}{16}\text{ in}) accordion-folded steel plate painted deep aubergine on its underside.\n\n# Chapter 5: Professional Practice\n\n## Unit 26: Preparing Your Portfolio\n\n* A portfolio represents a designer's professional identity, presenting selected design projects.\n* **Layout Specifications**:\n * Maintain a unified page orientation (landscape or portrait).\n * Design facing double-page spreads as complementary pairs.\n * Utilize horizontal hang-lines to structure visual flow, narrative rhythm, and text placement.\n * Use storyboards to organize page sequences prior to final assembly.\n\n## Unit 27: Writing a C.V. and Covering Letter\n\n* **Curriculum Vitae (C.V.) Rules**:\n * Length: Maximum of 1–2 printed pages.\n * Format: Chronological C.V. (education, work experience listed in reverse date order) or Skills-Based C.V. (categorizing technical, managerial, teamwork, and drafting skills).\n * Phrasings: Use active action verbs (*developed*, *organized*, *supervised*, *researched*); avoid passive language (*assisted*, *helped*).\n* **Covering Letter Rules**:\n * Always address letters directly to named individuals (avoid "Dear Sir or Madam").\n * State the specific position applied for, cite the job advertisement source, highlight relevant achievements, and reference background research on the firm.\n\n## Unit 28: Design Roles\n\n* **Design Team Hierarchy**:\n * *The Client*: Project head and financial controller holding ultimate approval power.\n * *The Designer / Design Team*: Spatial translators and project managers executing brief designs according to professional codes of conduct.\n * *Materials Manager / Quantity Surveyor*: Prepares bills of materials, monitors material cost changes, and forecasts cash flow projections.\n * *Main Contractor*: Manages site work, timelines, trade workers, and sub-contractors.\n * *Specialist Consultants*: Structural engineers, HVAC specialists, lighting designers, and IT consultants.\n* **Project Management Structure Types**:\n 1. *Minor Project*: Designer and contractor report directly to client.\n 2. *Management Contractor*: Contractor directs all sub-contractors directly.\n 3. *Construction Management*: Client contracts directly with all sub-contractors and consultants.\n\n## Unit 29: The Design Industry\n\n* **Employment Comparison**:\n * *Freelancing*: Low overheads, tax deductions, working from home; trade-offs include irregular hours, lack of space, and blending personal/work lives.\n * *Setting Up a Practice*: Professional standing, dedicated client meeting spaces, ability to command higher fees, standard office hours; trade-offs include high overheads, complex business accounting, and commercial risk.\n* **Professional Accreditation**:\n * Degree standard: Bachelor's degree from a FIDER-accredited (Foundation for Interior Design Education Research) institution.\n * Professional Qualification: Passing the NCIDQ (National Council for Interior Design Qualification) examination.\n\n## Unit 30: Setting Up on Your Own\n\n* **Business Practice Fundamentals**:\n * Gain prior industry experience within established firms before independent practice.\n * Generate clients via word-of-mouth recommendations, supplier showroom listings, trade directory ads, and recruitment agency listings.\n * Develop an explicit design identity and brand philosophy.\n * Maintain strict administrative filing, daily time management, structured project billing, and open bank/client communications.\n\n# Back Matter Resources\n\n## Key Glossary Terms\n\n* **Axonometric**: Paraline 3D projection keeping plan geometry true while projecting vertical heights up.\n* **Bubble Diagram**: Abstract visual planning map depicting spatial hierarchy, room sizes, and circulation relationships.\n* **Building Regulations**: Codified statutory codes ensuring health, safety, structural integrity, and energy standards.\n* **CAD**: Computer-Aided Design software for drafting, 3D modelling, and render simulations.\n* **Concept Board**: Presentation board compiling images, textures, and words to convey design directions.\n* **Cone of Vision**: The 60^ ext{o}$$ field of view visible in perspective drawing without edge distortion.
• Dead Loads: Static self-weight of structural building materials, walls, roofs, and fixed elements.
• Ergonomics: The science of fitting environments and products to human physical dimensions and movement.
• Live Loads: Dynamic, temporary weights imposed on structures by occupants, furniture, and environmental forces.
• Munsell System: A precise color notation space measuring Hue (spectrum circle), Value (black-to-white axis), and Chroma (saturation strength).
• Orthographic: 2D scaled architectural drawings comprising plans, elevations, and sections.
• Section: Vertical cut drawing through a structure revealing interior spaces, wall profiles, and ceiling heights.
• Vanishing Point (VP): Point on the perspective horizon line where parallel receding lines converge.

Professional Design Organizations

• ASID: American Society of Interior Designers (USA).
• BIDA: British Interior Design Association (UK).
• BITA: British Interior Textiles Association (UK).
• CSD: The Chartered Society of Designers (UK).
• IIDA: International Interior Design Association (Global).
• NCIDQ: National Council for Interior Design Qualification (North America).