Supporting Reference

Heating, Cooling, Lighting for the ExAC

Heating, Cooling, Lighting: Sustainable Design Methods for Architects, by Norbert Lechner (4th edition, Wiley, 2015), is the architect's guide to passive and active environmental systems. The 2026 ExAC Preparation Guide does not name it, and publishes no chapter-level citations for any book, so the chapter mapping on this page is Examitect's own: we treat it as supporting reading for six categories across Section 1 and Section 3, covering site analysis, engineering coordination, building science, and sustainable design.

Try a free ExAC practice question See plans

Heating, Cooling, Lighting overview

HCL at a glance

Full titleHeating, Cooling, Lighting: Sustainable Design Methods for Architects
AuthorNorbert Lechner
PublisherJohn Wiley & Sons, Inc.
Edition referenced4th Edition (2015)
Structure19 chapters organized around three themes: heating, cooling, and lighting
LanguagesEnglish
Primary audienceArchitecture students and practising architects who need a working knowledge of environmental systems from a design rather than an engineering perspective
ExAC relevanceNot named in the official ExAC Preparation Guide. Examitect treats it as supporting reading for six categories across Section 1 (Design and analysis) and Section 3 (Sustainability and final project), and does not map it to Sections 2 or 4.
Where to accessThrough John Wiley and Sons, university and college libraries, and many architecture offices. Check with your firm.

Why HCL matters for the ExAC

HCL is not one of the four primary reference documents the 2026 ExAC Preparation Guide names, so Examitect treats it as supporting reading. That distinction matters for how you allocate study time: the primary references carry the heavier exam load. But supplementary references are on the list for a reason, and HCL is there because the ExAC tests environmental reasoning, not just code compliance.

The six categories where HCL appears are site and environmental analysis, coordinating engineering systems, schematic design, design development, building science and systems, and sustainable design literacy. The chapter mapping below is Examitect's own, since the Preparation Guide publishes no chapter citations, and it lets you target your reading by category instead of reading the whole book.

When a question asks you to evaluate a design for passive solar performance, choose an appropriate shading strategy for a given facade orientation, or explain why climate zone affects glazing decisions, HCL is the reference that builds the physical reasoning behind the answer. The primary references may identify the requirement; HCL explains why it works.

How to study HCL for the ExAC

  • Read by category, not chapter order. Examitect's mapping names specific chapters for each category; start with those, not with Chapter 1.
  • Read HCL chapters after you have covered the primary references for each category. Chapter 5 (Climate) lands differently once you have read CHING site pages; Chapter 16 (Mechanical Equipment) is more useful after CHING Chapter 11.
  • For site analysis, pair Chapter 5 (Climate) and Chapter 11 (Site Design, Community Planning, and Landscaping) with CHING to build a unified mental model of climate, site, and solar access.
  • For sustainable design, read Chapters 2, 7, and 8 alongside the NECB. HCL explains the physics; the code provides the compliance framework.
  • Sketch each passive strategy as you read it. Direct-gain solar systems, Trombe walls, natural ventilation paths, and light shelves all have spatial geometry you need to recognize under exam conditions.
  • Pair HCL reading with Examitect practice questions. Each scenario question shows you how a concept appears in an exam context and confirms whether you understood the chapter or just read it.

ExAC sections HCL supports

  1. Section 1

    Design and analysis. HCL is supplementary for four Section 1 categories: site and environmental analysis (Ch 5, 11), coordinating engineering systems (Ch 3, 12, 13, 14, 16), schematic design (Ch 1, 19), and design development (Ch 15, 16).

  2. Section 3

    Sustainability and final project. HCL is supplementary for two Section 3 categories: building science and systems (Ch 2, 3, 4, 15) and sustainable design literacy (Ch 2, 7, 8). HCL is not cited for Section 2 or Section 4.

Inside HCL: 19 chapters across heating, cooling, and lighting

The 4th edition is organized around the three subjects in its title. Each part moves from passive strategies to active mechanical systems, so the physical principles precede the engineering. The table below maps chapters to the ExAC categories they serve. The mapping is Examitect's own; the Preparation Guide cites no chapters for any book.

Chapter group Chapters in Examitect's mapping Content and ExAC categories served
Design foundations and climate Ch 1, 2, 3, 4, 5 Ch 1 (Heating, Cooling, and Lighting as Form-Givers in Architecture) frames environmental systems as generators of architectural form (schematic design). Ch 2 (Sustainable Design and Energy Sources) covers sustainability frameworks, climate change, and energy source comparisons (sustainable design literacy). Ch 3 (Basic Principles) explains heat transfer: convection, radiation, thermal resistance, time lag, and thermal mass (engineering coordination, building science). Ch 4 (Thermal Comfort) covers the psychrometric chart, metabolic rate, and adaptive comfort models (building science). Ch 5 (Climate) provides regional climate classification, dividing the United States and Canada into seventeen climate regions, with climate data tables for US reference cities and design strategies for each climate type (site and environmental analysis).
Solar geometry, passive solar, and photovoltaics Ch 7, 8 Ch 7 (Passive Solar) covers direct-gain systems, Trombe walls, sunspaces, and heat-storage materials, with design guidelines and sizing examples (sustainable design literacy, building science). Ch 8 (Photovoltaics and Active Solar) covers PV system sizing, building-integrated PV, solar hot-water collectors, and active solar applications (sustainable design literacy). Ch 6 (Solar Geometry) underpins both chapters with sun-path diagrams and solar access tools but is not called out separately in our mapping.
Shading, passive cooling, and site design Ch 11 Ch 11 (Site Design, Community Planning, and Landscaping) covers solar access planning, site selection for passive performance, microclimate management, and vegetation strategies (site and environmental analysis). Ch 9 (Shading and Light Colors) and Ch 10 (Passive Cooling) cover shading device design, passive cooling, and natural ventilation in depth; those chapters are not called out separately in our mapping but support the engineering coordination categories.
Lighting: natural and electric Ch 12, 13, 14 Ch 12 (Lighting) covers vision, illumination levels, brightness ratios, glare control, and the biology of light (coordinating engineering systems). Ch 13 (Daylighting) covers daylight factor, sidelighting, toplighting, advanced window strategies, and glazing materials (engineering coordination, design development). Ch 14 (Electric Lighting) covers lamp types, luminaires, controls, maintenance, and energy standards (coordinating engineering systems).
Thermal envelope, mechanical systems, and integration Ch 15, 16, 19 Ch 15 (The Thermal Envelope: Keeping Warm and Staying Cool) covers heat loss, heat gain, solar reflectivity, insulation strategies, and envelope performance criteria (building science, design development). Ch 16 (Mechanical Equipment for Heating and Cooling) covers heating systems, heat pumps, geo-exchange, and air-conditioning for both small and large buildings (engineering coordination, design development). Ch 19 (Checklist for Designing Integrated Sustainable Buildings) is a consolidated design tool covering site, form, windows, daylighting, shading, and envelope (schematic design).

If you are short on time, focus first on the chapters with the highest category overlap. Chapters 3, 12, 13, 14, and 16 carry the engineering coordination categories. Chapters 2, 7, and 8 carry sustainable design literacy. Chapters 5 and 11 carry site analysis.

Key HCL terms every ExAC candidate should know

HCL introduces vocabulary that appears in ExAC environmental and systems questions. Learn these 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. Direct gain, Trombe walls, and sunspaces are the three main systems covered in Chapter 7.
Thermal massHeavy materials (concrete, masonry, water) that absorb daytime solar heat and release it at night, moderating indoor temperature swings. Sizing and placement are covered in Chapter 7.
Solar heat gain coefficient (SHGC)The fraction of incident solar radiation that passes through a glazing assembly. High SHGC supports passive heating in cold climates; low SHGC limits overheating in cooling-dominated climates. The NECB sets no prescriptive SHGC limit: it controls fenestration by maximum overall thermal transmittance and by fenestration and door to gross wall area ratio, and SHGC appears only as a modelling input in the Part 8 performance path.
Passive coolingStrategies that remove heat from a building without mechanical refrigeration: cross ventilation, stack ventilation, earth tubes, evaporative cooling, and shading. Covered in Chapters 9 and 10.
Natural ventilationAir movement driven by wind pressure or buoyancy (stack effect) rather than fans. Requires carefully placed openings and pressure differentials. Design principles in Chapter 10.
DaylightingThe controlled use of natural light to illuminate interior spaces, reducing electric lighting energy use and improving occupant comfort. Strategy, metrics, and glazing options in Chapter 13.
Daylight factorThe ratio of interior illuminance to simultaneous exterior illuminance under an overcast sky, expressed as a percentage. The standard metric for evaluating daylighting adequacy in a space.
Climate zoneA geographic classification based on temperature, humidity, and solar data, used to select appropriate passive and active strategies. Chapter 5 divides the United States and Canada into seventeen climate regions and provides climate data tables for US reference cities.
Solar orientationThe positioning of a building relative to the sun path. In Canada, placing the long axis east-west maximizes south-facing glazing and simplifies shading design. Covered in Chapter 5 and Chapter 11.
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. Canadian cities typically have significantly higher HDD values than comparable US cities.
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. A design development tool covered in Chapter 13.
Shading coefficientA measure of how effectively a shading device reduces solar heat gain through a glazed opening relative to an unshaded reference glass. Useful when comparing exterior overhang and screen options.

Tips for Intern Architects reading HCL

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

Tip 1, read by ExAC category, not by chapter order. The chapters mapped to building science (Ch 2, 3, 4, 15) are spread across very different parts of the book. Going straight to those chapters after your primary reading is faster than starting at Chapter 1 and hoping you hit the right material.

Tip 2, connect each principle to a building you know. When Chapter 7 describes how a south-facing clerestory admits low winter sun while a deep overhang blocks summer 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 in new project situations, not definition recall.

Tip 3, sketch the passive strategies. Passive solar heating, cross ventilation, light shelves, and solar shading all have spatial geometry. Sketching each strategy, even crudely, forces you to understand the orientation, the openings, and the section logic. That understanding is exactly what ExAC scenario questions test.

Tip 4, adapt the US climate data to Canada. Chapter 5's climate region map covers the United States and Canada, but its climate data tables use US reference cities only; there are no tables for Canadian cities. Most Canadian locations are firmly heating-dominated. The book's US-centric examples often assume milder winters; adjust those design guidelines when applying them to a Canadian context.

Tip 5, use your IAP projects as a reading guide. If you are currently coordinating with a mechanical consultant on an HVAC system, read Chapter 16 now. If the project has a daylighting strategy, read Chapters 13 and 14 now. HCL chapters read alongside current work produce significantly faster retention than reading in isolation months before the exam.

Tip 6, pair HCL with the NECB when studying energy performance. The National Energy Code of Canada for Buildings (NECB) sets the compliance numbers: maximum overall thermal transmittance by heating-degree-day zone, a maximum fenestration and door to gross wall area ratio, and lighting power allowances. HCL explains why those numbers exist physically. Reading them together closes the gap between code compliance and design reasoning, which is where ExAC sustainable design questions live.

Common ExAC scenarios where HCL is the answer

These question types draw on the reasoning HCL builds. When you see one, ask yourself which physical principle applies before looking at the answer options.

  • 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 approach for the south facade?
  • The project is on the NECB prescriptive path, which caps the fenestration and door to gross wall area ratio and sets a maximum overall thermal transmittance for fenestration by heating-degree-day zone, but puts no limit on solar heat gain coefficient. The architect still wants to control solar gain on the west and east facades. What is the physical reasoning for treating those faces differently from the south?

How HCL compares to other ExAC references

HCL is a depth reference for environmental systems reasoning. Use this comparison to decide what to read for each type of question.

ReferenceWhat it is forHow HCL relates
HCL Passive and active strategies for heating, cooling, and lighting, explained from an architect's design perspective. The physical 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 explains how that wall gains and loses heat. Both are cited for building science in Section 3; CHING is primary, HCL is supplementary.
CHOP The 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 2020 The model building code for structural, fire safety, envelope, and energy compliance. Primary for all of Section 2. The NBC sets the environmental separation requirements in Division B Part 5, and its energy provisions for housing and small buildings sit in Section 9.36. Part 6 is Heating, Ventilating and Air-conditioning, and energy requirements for larger buildings come from the NECB. HCL explains the physical principles behind those requirements. Neither replaces the other.
NECB Energy compliance requirements for buildings above Part 9. The primary reference for ExAC energy categories. The NECB prescribes maximum overall thermal transmittance (U-value) for opaque assemblies and for fenestration by heating-degree-day zone, a maximum fenestration and door to gross wall area ratio, and interior and exterior lighting power allowances. It sets no SHGC limits: SHGC appears only as a modelling input in the Part 8 performance path. HCL explains the principles that underpin those values, which helps you reason through NECB compliance scenarios.
The Architect's Studio Companion A 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 a quick reference for system types; HCL goes deeper on passive design and climate analysis.

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 Examitect maps HCL. Each answer explanation identifies the physical principle at work and points back to the relevant chapter so you can re-read the specific pages you need.

Full-length mock exams 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 Examitect's plans when you are ready for the full question bank.

FAQ

HCL FAQ

Heating, Cooling, Lighting: Sustainable Design Methods for Architects is a textbook by Norbert Lechner, published by John Wiley and Sons (4th edition, 2015). It covers passive and active strategies for thermal comfort and daylighting across 19 chapters, written from an architect's perspective rather than an engineer's.

Supplementary. The 2026 ExAC Preparation Guide names four primary reference documents, CHOP (2020 edition), the Internship in Architecture Program, NBC 2020 and NECB 2020, and Heating, Cooling, Lighting is not among them. Examitect treats it as supporting reading for six categories across Section 1 (Design and analysis) and Section 3 (Sustainability and final project), where CHING and CHOP do the heavy lifting. HCL provides additional depth on environmental systems and passive design reasoning.

In Examitect's mapping, the chapters that carry the most weight are 1, 2, 3, 4, 5, 7, 8, 11, 12, 13, 14, 15, 16, and 19. Chapter 5 (Climate) and Chapter 11 (Site Design) are cited for site and environmental analysis; Chapters 3, 12, 13, 14, and 16 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 those principles helps you reason through NECB compliance questions and sustainable design scenarios on the ExAC.

No. Examitect's mapping targets specific chapters rather than the entire book. For Section 1 site analysis and engineering coordination, concentrate on Chapters 3, 5, 11, 12, 13, 14, and 16. For Section 3 sustainable design and building science, concentrate on Chapters 2, 3, 4, 7, 8, and 15. Chapter 19 is a short integration checklist worth reading for schematic design.

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 physical reasoning. For assembly and detailing questions, CHING is the primary reference.

Read the relevant HCL chapters after you have covered the primary references 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 can see how the concepts appear in exam-style scenarios.

Keep exploring

Other ExAC reference books.

Heating, Cooling, Lighting is a supporting reference. These are the core references to 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.

Yardsticks

Hanscomb Yardsticks for Costing. Canadian elemental cost data by building type and region, for Section 1 Cost Management.

All supporting references

See the full list of supporting references in Examitect's mapping, including where each one appears by category and section.