Heating, Cooling, Lighting

Placeholder page for the supporting reference Heating, Cooling, Lighting, part of the Examitect reading list for the ExAC.

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HCL at a glance

The quick facts an Intern Architect needs before opening the book for the first time.

Full titleHeating, Cooling, Lighting: Sustainable Design Methods for Architects (commonly cited title; verify against your copy)
AuthorNorbert Lechner (commonly attributed; verify against your copy)
PublisherJohn Wiley & Sons (commonly cited publisher; verify against your copy)
Current edition on Examitect's study plan4th Edition
LanguagesEnglish
Primary audienceArchitecture students and practising architects who need a working understanding of environmental systems from a design perspective rather than an engineering one
ExAC relevanceSupplementary resource on Examitect's ExAC study plan for six categories across Section 1 (Design and analysis) and Section 3 (Sustainability and final project). Not cited for Sections 2 or 4.
Where to accessThrough your institution's library or directly from the publisher. Check with your firm or provincial association for access options.

Why HCL matters for the ExAC

HCL is a supplementary reference on Examitect's ExAC study plan, not a primary one. That distinction matters for how you allocate study time: the primary resources carry the heavier exam load. But supplementary references show up on the reading list for a reason, and HCL is there because the ExAC tests environmental reasoning, not just code compliance.

The categories where HCL appears are site and environmental analysis, coordinating engineering systems, schematic design, design development, building science and systems, and sustainable design literacy. In each case, Examitect's study plan cites specific chapters rather than the entire book. That tells you where to focus: chapters 5 and 11 for site questions, chapters 3 and 12 through 14 for engineering coordination, chapters 2, 7, and 8 for sustainable design, and chapters 15 and 16 for lighting-related design development topics.

If an ExAC question asks you to evaluate a design option against passive solar performance, select an appropriate shading strategy for a given orientation, or explain how a building's climate zone should inform glazing decisions, HCL is the reference that builds the reasoning behind the answer. The primary reference (usually CHING or the NBC) may identify the requirement; HCL explains why it works.

ExAC sections

See the ExAC sections table below for study-plan coverage.

What Heating, Cooling, Lighting is

Heating, Cooling, Lighting (HCL) is a textbook that explains how buildings gain and lose heat, how natural and mechanical systems control thermal comfort, and how daylight and electric light work together to illuminate space. What sets it apart from a standard mechanical engineering text is its audience: the book is written for architects, not engineers. It explains system behaviour in physical and spatial terms, using building form, orientation, glazing ratios, shading geometry, and material properties as the primary design levers.

The 4th edition is structured around the three subjects in its title. The heating portion covers passive solar strategies (direct gain, thermal mass, shading), climate analysis, and the mechanical systems that supplement passive approaches. The cooling portion addresses passive cooling techniques such as natural ventilation and earth cooling, then transitions to active mechanical systems. The lighting portion covers daylight fundamentals, daylighting design strategies such as light shelves and toplighting, and electric lighting systems. Because the subjects interact, the book treats them as a whole: the glazing ratio that maximizes winter solar gain also creates summer overheating risk, and managing that tradeoff is precisely what architects need to understand.

Inside HCL: chapter overview

The 4th edition spans roughly 19 chapters (verify against your copy). Based on widely available descriptions of the book's structure and the chapters cited in Examitect's study plan, the content falls into four broad areas.

AreaChapters cited in Examitect's study planWhat it covers
Fundamentals and climate Chapters 1, 2 Sustainable design principles, climate classification, solar geometry, and the relationship between climate data and building strategy. Cited for schematic design (Ch 1) and sustainable design literacy (Ch 2).
Passive and active heating Chapters 3, 4, 5 Solar radiation fundamentals, passive solar strategies (direct gain, thermal mass, Trombe walls, sunspaces), site planning for solar access. Chapter 5 is cited for site and environmental analysis; chapters 3 and 4 for building science and systems.
Passive cooling, ventilation, and active systems Chapters 7, 8, 11, 12, 13, 14 Passive cooling strategies, natural ventilation design, site microclimate, and mechanical HVAC systems. Chapters 7 and 8 are cited for sustainable design literacy; chapter 11 for site analysis; chapters 12 through 14 for coordinating engineering systems.
Lighting and integration Chapters 15, 16, 19 Daylighting principles, daylighting design strategies (sidelighting, toplighting, light shelves), electric lighting systems, and design integration. Chapters 15 and 16 are cited for design development and building science; chapter 19 for schematic design.

If you are short on time, chapters 5, 11, and 12 through 14 carry the most weight for engineering coordination questions. Chapters 2, 7, and 8 are the core sustainable design chapters. Chapters 15 and 16 are your go-to for daylighting and lighting integration questions in design development.

Key HCL terms every ExAC candidate should know

HCL introduces vocabulary that the ExAC uses in environmental and systems questions. Learn these terms early so you are not parsing the question when you should be choosing the answer.

TermWhat it means in practice
Passive solar heatingA design strategy that collects and stores solar heat through building form, orientation, glazing, and thermal mass, with no mechanical equipment.
Thermal massHeavy materials (concrete, masonry, water) that absorb daytime solar heat and release it at night, moderating indoor temperature swings.
Solar heat gain coefficient (SHGC)The fraction of incident solar radiation that passes through a glazing assembly. High SHGC is useful for passive heating; low SHGC limits summer overheating.
Passive coolingStrategies that remove heat from a building without mechanical refrigeration: cross ventilation, stack ventilation, earth tubes, and shading.
Natural ventilationAir movement driven by wind pressure or buoyancy (the stack effect) rather than fans. Requires carefully placed openings and pressure differences.
DaylightingThe controlled use of natural light to illuminate interior spaces, reducing electric lighting energy use and improving occupant comfort.
Climate zoneA geographic classification based on temperature, humidity, and solar data, used to select appropriate passive and active strategies for a project location.
Solar orientationThe positioning of a building relative to the sun path. Optimizing orientation (long axis east-west in Canada) reduces heating loads and simplifies shading design.
Heating degree days (HDD)A cumulative measure of how cold a climate is over a year. Used to compare heating demands between locations and to size heating systems.
Cooling degree days (CDD)A cumulative measure of how hot a climate is over a year. Used to estimate cooling loads and compare active system requirements between locations.
Light shelfA horizontal projection inside or outside a window that reflects daylight deeper into a room while shading the lower glazing zone from direct sun.
Shading coefficientA measure of how effectively a shading device reduces solar heat gain through a glazed opening compared to an unshaded reference glass pane.

How HCL compares to other ExAC references

HCL is a depth reference for environmental systems. Use this comparison to decide what to read for which kind of question.

ReferenceWhat it's forHow HCL relates
HCLPassive and active strategies for heating, cooling, and lighting, explained from an architect's design perspective.The reasoning layer. HCL explains why a design decision affects thermal or lighting performance.
CHING (Building Construction Illustrated)The primary reference for building science, assemblies, materials, and detailing across Sections 1 and 3.CHING shows you what a wall assembly looks like. HCL tells you how that wall gains and loses heat. Both are cited for building science in Section 3; CHING is primary, HCL is supplementary.
CHOPThe primary practice reference for project delivery, engineering coordination, and every project phase.CHOP covers the architect's role in coordinating engineering consultants. HCL gives you the technical vocabulary to understand what the mechanical and electrical engineers are proposing.
NBC 2020The model building code for structural, fire safety, envelope, and energy compliance. Primary for all of Section 2.The NBC sets Part 5 environmental separation requirements and Part 6 energy provisions. HCL explains the physical principles behind those requirements. Neither replaces the other.
NECBEnergy compliance requirements for buildings above Part 9. The primary reference for ExAC category 5.25.The NECB prescribes values (R-values, SHGC limits, lighting power density). HCL explains the principles that underpin those values. Reading HCL helps you reason through NECB compliance scenarios.
The Architect's Studio CompanionA supplementary reference that covers structural and mechanical systems in condensed form, cited alongside HCL for engineering coordination categories.Both are supplementary for engineering coordination. The Studio Companion is more of a quick reference for system types; HCL goes deeper on passive design and climate analysis.

How to study HCL for the ExAC

  • Do not read HCL cover to cover. Examitect's ExAC study plan cites specific chapters for each category. Start with those chapters, not with chapter 1.
  • Read the HCL chapters for a category after you have covered the primary resources for that category. HCL deepens what CHING or the NBC introduces; it rarely stands alone on an exam question.
  • For site and environmental analysis, read chapters 5 and 11 alongside CHING pages 1.02 through 1.44. Build a unified mental model of how site, climate, and solar access intersect.
  • For engineering systems coordination, read chapters 12 through 14 and connect each system type (HVAC, radiant, ventilation) to the space planning and ceiling coordination implications you will encounter at work and on the exam.
  • For sustainable design, read chapters 2, 7, and 8 alongside the LEED and BC Energy Step Code references cited in Examitect's study plan. HCL provides the physical reasoning; the other references provide the rating and compliance frameworks.
  • For each passive strategy you read about, sketch the corresponding design move. Active recall through sketching moves faster than re-reading when you're short on time before exam day.

ExAC sections HCL supports

Examitect's ExAC study plan lists HCL as supplementary for the categories below. Chapters are listed as cited in the study plan.

ExAC section and categoryHCL chapters citedRole on Examitect's study plan
Section 1: Site and environmental analysis
(categories 2.1, 2.2, 2.3)		Chapters 5, 11Supplementary. Covers solar access, site microclimate, and climate-responsive siting principles alongside primary references CHING and CHOP.
Section 1: Coordinating engineering systems
(categories 3.1, 3.2, 3.3)		Chapters 3, 12, 13, 14, 16Supplementary. Covers heating and cooling system types, ventilation principles, and lighting systems, alongside primary references CHING and CHOP.
Section 1: Schematic design
(category 6.1)		Chapters 1, 19Supplementary. Covers sustainable design intent and design integration, alongside primary references CHING and CHOP.
Section 1: Design development
(category 7.1)		Chapters 15, 16Supplementary. Covers daylighting and lighting system integration during design development, alongside primary references CHING and CHOP.
Section 3: Building science and systems
(category 8.2)		Chapters 2, 3, 4, 15Supplementary. Covers climate fundamentals, passive solar principles, and daylighting basics, alongside primary references CHING and CHOP.
Section 3: Sustainable design literacy
(categories 13.1, 13.3)		Chapters 2, 7, 8Supplementary. Covers climate change and design response, passive cooling, and sustainable architectural strategies, alongside primary references CHING and CHOP.

HCL does not appear in Examitect's study plan for Section 2 (Codes) or Section 4 (Construction and practice). Focus your HCL time on Sections 1 and 3.

Tips for Intern Architects reading HCL

HCL is a textbook written for architecture students, but it's also a practical reference for working architects who need to communicate with mechanical engineers and make informed design decisions during Internship in Architecture Program (IAP) work. Here's how to get the most out of it.

Tip 1, read by category, not by chapter order. Start with the chapters cited for the ExAC categories you are working on. Chapter 12 (mechanical systems) will land differently after you have read CHING chapter 11 (building systems) than it will if you open HCL cold at chapter 1.

Tip 2, connect each principle to a building you know. When HCL describes how a south-facing clerestory admits low winter sun, picture a building you have worked on or visited. The physical principle sticks faster when it has a spatial anchor. The ExAC tests recognition of those principles in new project situations, not memorization of definitions.

Tip 3, sketch the passive strategies, don't just read them. Passive solar heating, cross ventilation, light shelves, and solar shading all have spatial logic. Sketching each strategy, even crudely, forces you to understand the geometry. That understanding is what the ExAC tests when it gives you a plan or section and asks you to evaluate a design option.

Tip 4, learn the Canada-specific climate context. HCL covers climate zones that span heating-dominated, cooling-dominated, and temperate conditions. Most Canadian cities sit firmly in heating-dominated zones with significant diurnal temperature swings. Pay attention to how the book discusses strategies for cold climates specifically, and note where Canadian climate assumptions differ from the US-centric examples.

Tip 5, use your IAP projects as a reading guide. If you are working on a project with a meaningful daylighting strategy, read the daylighting chapters now. If you are coordinating with a mechanical consultant on an HVAC system, read the systems chapters now. The overlap between current IAP work and HCL reading produces much faster retention than reading in isolation.

Tip 6, pair HCL with NECB when studying energy performance. The National Energy Code of Canada for Buildings (NECB) sets the numbers. HCL explains why those numbers matter physically. Reading them together closes the gap between code compliance and design reasoning, which is exactly where ExAC sustainable design questions live.

Common ExAC scenarios where HCL is the answer

These question types draw on the reasoning HCL builds. If you see one, your first instinct should be to ask "what physical principle applies here."

  • A schematic design shows a building with a large south-facing glazed wall and no shading. The design team claims it will be energy-efficient. Which climate condition would make this claim defensible, and which would expose it as a problem?
  • A mechanical engineer proposes a forced-air HVAC system for an office building. The architect wants to evaluate natural ventilation as an alternative. What site conditions and building configuration factors need to be assessed first?
  • A client asks why the proposed design includes high clerestory windows on the south wall instead of floor-to-ceiling glazing. What are the daylighting and thermal performance arguments for the clerestory approach?
  • During design development, the interior designer proposes a dark ceiling finish in the main office. The architect is concerned about daylighting performance. What is the specific technical reason for the concern?
  • The project is located in a climate with hot summers and cold winters. The design includes significant thermal mass in the floor slab. When is that mass a benefit, and when does it become a liability?
  • A sustainability consultant recommends adding exterior shading to the west facade of an office building in a Canadian city. What solar geometry principle supports that recommendation, and how does it differ from the south facade treatment?
  • The NECB compliance path requires the project team to limit glazing SHGC on west and east facades. The architect wants to understand why west and east faces are treated differently from south. What is the reasoning?

How Examitect reinforces HCL

HCL is a supplementary reference, which means ExAC questions tied to it are scenario-based: you won't be asked to recall a formula, but you will be asked to choose the design response that reflects sound environmental reasoning. Examitect's question bank includes questions on passive solar design, natural ventilation, daylighting strategy, and climate-responsive site planning, all drawn from the categories where HCL appears on Examitect's study plan. Each answer explanation identifies the physical principle at work and points you to the relevant source material so you can re-read the specific pages you need.

You also get full-length mock exams that mirror ExAC pacing across all four sections, so you can see how HCL-related questions appear alongside primary-reference questions in a realistic test format. Try a few sample questions first, then check pricing when you're ready for the full bank.

HCL and ExAC FAQ

Heating, Cooling, Lighting is a textbook on sustainable environmental systems design for architects, commonly attributed to Norbert Lechner and published by Wiley. The 4th edition covers passive and active strategies for thermal comfort and daylighting, presented from an architect's perspective rather than an engineer's.

Supplementary. On Examitect's ExAC study plan, Heating, Cooling, Lighting is listed as a supplementary resource for six categories across Section 1 and Section 3. The primary references for those categories are CHING and CHOP. HCL provides additional depth on environmental systems and passive design reasoning.

Based on Examitect's ExAC study plan, the most frequently cited chapters are 1, 2, 3, 5, 7, 8, 11, 12, 13, 14, 15, 16, and 19. Chapters 5 and 11 are cited for site and environmental analysis; chapters 3, 12, 13, and 14 for engineering systems coordination; and chapters 2, 7, and 8 for sustainable design literacy.

The National Energy Code of Canada for Buildings sets prescriptive and performance compliance thresholds. Heating, Cooling, Lighting explains the physical principles behind those thresholds: how solar gain, thermal mass, natural ventilation, and daylighting work in practice. Understanding the principles helps you reason through NECB compliance questions and sustainable design scenarios on the ExAC.

No. Examitect's ExAC study plan cites specific chapters rather than the entire book. Focus on the chapters tied to the categories you are studying. For Section 1 site analysis and engineering coordination, concentrate on chapters 3, 5, 11, 12, 13, 14, and 16. For Section 3 sustainable design, concentrate on chapters 2, 7, and 8.

Building Construction Illustrated (CHING) covers the full spectrum of building construction: structure, assemblies, materials, and detailing. Heating, Cooling, Lighting goes much deeper on environmental systems, passive design strategies, and daylighting. For engineering coordination and sustainable design questions, HCL provides more detailed reasoning. For assembly and detailing questions, CHING is the primary reference.

Read the relevant HCL chapters after you have covered the primary resources for each category. HCL gives you a second angle on topics already introduced by CHING and the NBC. Pair your HCL reading with Examitect practice questions that reference this source so you see how the concepts appear in exam-style scenarios.

Keep exploring

Other ExAC reference books.

Heating, Cooling, Lighting is a supporting reference on Examitect's ExAC study plan. These are the primary references you should cover first.

CHING

Building Construction Illustrated. The primary reference for building science, assemblies, and site analysis across Sections 1 and 3.

CHOP

Canadian Handbook of Practice. The primary reference for practice management, project delivery, and every project phase in Sections 1, 3, and 4.

NBC 2020

National Building Code of Canada. The primary reference for every category in ExAC Section 2, including envelope and energy provisions.

NECB

National Energy Code of Canada for Buildings. Sets the energy compliance requirements that HCL helps you understand from first principles.

RSMeans

Construction cost data for elemental estimating and cost-management questions in Section 1.

All supporting resources

See the full list of supplementary references on Examitect's ExAC study plan, including where each one appears by category and section.