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  • PublisherCIBSE
  • Product CodeGVA/15
  • Number of pages402
  • Publication DateMar 2015
  • ISBN9781906846541

GVA/15 CIBSE Guide A: Environmental Design 2015


PDF Format







PDF Format






GVA/15 CIBSE Guide A: Environmental Design 2015

Notice about delivery of hard copy publications during the current coronavirus situation

As a result of the coronavirus lockdown, we are only able to post hard copy publications every few weeks. Apologies for any inconvenience this may cause. To check on the status of your order, please email

Note: Corrections have been issued to Guide A. These are detailed in the table of 'Corrigenda and reprints' below. All such corrections made to date are incorporated in the downloadable pdf available from this page. The table also includes a link to allow you to download the latest Corrigenda, dated April 2019, as a separate document. As stated, both the downloadable pdf and latest hard copy both include all corrections issued to date.

Note 2An important standard relating to filters is referenced in this title, BS EN 779: 2012 'Particulate air filters for general ventilation. Determination of the filtration performance'. This replaced the previous 2002 edition, but is now itself withdrawn. It was superseded in July 2018 by BS EN ISO 16890 (in 4 parts).

The new classifications are based on expanded tests for particulates and there is no 1-to-1 relationship with the EN 779-based classes. There are implications for both new and existing HVAC systems and potentially for guidance on natural ventilation. In due course, CIBSE guidance will be updated to reflect this change but in the mean time, you should note it.

This Eurovent document provides a useful summary of the changes:


CIBSE Guide A: Environmental design is the premier technical/reference source for designers and installers of building services, especially low energy and environmentally sustainable buildings. This is the eighth edition, which comprehensively updates its predecessor. It also contains many significant changes in both format and content.

Chapter 0, Quality in environmental design, is new to the Guide and has been added to consider the quality of the environmental design. It identifies two specific requirements for achieving quality in building design, namely adopting a holistic approach to the design, and a system to assure the quality of the design calculations and decisions, i.e. a quality assurance procedure.

The other chapters in this Guide each deal with an individual aspect of environmental design, namely criteria for design (e.g. comfort criteria, weather data etc.) and methods of calculation such as fabric performance, heating and ventilation system sizing, methods for thermal comfort evaluation, energy demand etc.

The updated contents acknowledge and satisfy current UK legislation, specifically the 2013 Building Regulations Approved Documents L and F, and the recommendations of the Energy Performance of Buildings Directive. Additionally, the authors of each chapter have incorporated the latest published research and recognised best design practice to ensure that environmental design engineers and installation engineers can practise at the forefront of their profession.

Note: Chapter 2 of Guide A: 2015 supersedes TM34 Weather Data with Climate Change Scenarios (2004).

Corrigenda and reprints
PDF amended  September 2015 to incorporate corrections to prelim pages (iii), (iv) and (v); text pages 5-5, 5-62, 5-84, 6-4, 6-5, 8-8, 8-19; Appendix 5.A8 pages A8-4, A8-6.
PDF amended January 2016 to incorporate corrections to text pages 0-7, 0-8, 3-11, 3-12, 3-19, 3-37, 3-42, 5-101, 5-102, 5-103, 7-21, 8-7, 8-8.

Guide A Reprinted incorporating all previous orrections February 2016
PDF amended June 2016 to incorporate corrections to text pages 1-11, 3-33, 5-28, 5-33, 5-77, 5-97, 5-98.
PDF amended August 2016 to incorporate correction to page 5-84.

Guide A Reprinted incorporating all previous corrections October 2016.
PDF amended March 2017 to incorporate corrections to pages 4-28 and 4-29
PDF amended November 2017 to incorporate correction to page 6-8. 
PDF amended February 2018 to incorporate corrections to pages 5-13, 5-29, 5-33 to 35, 5-37, 5-56, 5-57, 5-62, 5-66, 5-72, 5-77, 5-86 and 8-12

Guide A Reprinted incorporating all previous corrections March 2018
PDF amended April 2018 to incorporate corrections to pages 0-10, 1-23, 2-35 and 4-10
PDF amended June 2018 to incorporate corrections to page 3-15

Guide A Reprinted incorporating all previous corrections May 2019
PDF amended July 2019 to incorporate corrections to pages 4-7 and 5-35.

Latest Corrigenda (v15) available here.

Guide A: Environmental Design Launch 

Video highlights and full audio recording are available from the launch event for CIBSE Guide A: Environmental Design 2015 held on 22nd July 2015 at the Grand Connaught Rooms, London featuring: 

Download slides

  • Guide A Steering Group Chair Derrick Braham 
  • Chapter 0 Quality in Environmental Design - Foroutan Parand 
  • Chapter 1 Environmental Criteria for Design - Fergus Nicol 
  • Chapter 2 External Design Data - Geoff Levermore represented by Derrick Braham
  • Chapter 3 Thermal properties of Building Structures – Brian Anderson represented by Michael Holmes
  • Chapter 4 Ventilation and Infiltration - Martin Liddament 
  • Chapter 5 Thermal Response and Plant Sizing - Chair Michael Holmes / Chair David Williams 
  • Chapter 6 Internal Heat Gains - David Arnold 
  • Chapter 7 Moisture transfer and Condensation, Chris Sanders represented by Michael Holmes
  • Chapter 8 Health Issues - Marialena Nikolopolou represented by Chair Derrick Braham

Supplementary files

As per the previous edition of Guide A, this edition is supported by a number of data files. These can now be accessed on-line from an index page here or as indicated below by Chapter.

Note: changes made by the Corrigenda of 24 Sep 2015 to Appendix A8 to Chapter 5 will be incorporated in these files.

Chapter 0, comprising:

  •    Blank PAMDOC and
  •    PAMDOC example

These can be accessed here

Chapter 2, comprising 

  • Annex: Solar radiation, long-wave radiation and daylight
  • World clear sky solar irradiance tables (by latitude)
  • External design data (Worldwide) with index of locations to 139 countries and nummerous locations within each
  • Figure 2.8 Wind roses for the UK
  • Table 2.9 Frequency of dry/wet bulb temperatures (June–September)
  • Table 2.12 Solar irradiation on inclined planes
  • Table 2.13 Solar irradiance on vertical and horizontal surfaces
  • Table 2.14 Sol-air temperatures
  • Table 2.19 Frequency of hourly wind speed by direction
  • Table 2.20 Frequency of hourly wind speed by temperature
  • Table 2.24 Predicted coincident dry and wet bulb temperatures (summer
  • Table 2.25 Predicted coincident dry and wet bulb temperatures (winter)

These can be accessed here

Chapter 5, comprising:

  •    Additional Appendices - ie A7, A8 (amended by Corrigena dated 24 Sep 2015), A9, A10, A11 and A12
  •    Table 5.16 Cooling loads (unshaded) (UK)
  •    Table 5.17 Cooling loads (shaded) (UK)
  •    Table 5.18 Banded weather data
  •    Table 5.X1 Cooling loads (unshaded) (worldwide)
  •    Table 5.X2 Cooling loads (shaded) (worldwide)

These can be accessed here

As an alternative, should it be required the whole set of Supplementary Files can be downloaded from here

Note: this is a large file so this may take some time to download


0 Quality in environmental design

0.1 Introduction

0.2 The design process

0.3 Design calculations quality plan

0.4 Sources of uncertainty

0.5 User issues

0.6 Performance assessment methods (pam)


1 Environmental criteria for design

1.1 Introduction

1.2 Notation and definitions

1.3 Thermal environment

1.4 Modelling thermal comfort

1.5 Environmental criteria

1.6 Additional factors potentially affecting comfort

1.7 Outdoor thermal comfort

1.8 Determination of required outdoor air supply rate

1.9 Visual environment

1.10 Noise

1.11 Vibration


Appendix 1.A1: Determination of predicted mean vote (pmv)

Appendix 1.A2: Measuring operative temperature

2 External design data

2.1 Introduction

2.2 Notation

2.3 UK near-extreme weather data

2.4 UK cold weather data

2.5 UK warm weather data

2.6 Wet and dry bulb temperatures

2.7 Worldwide weather data

2.8 Solar and illuminance data

2.9 Wind data

2.10 Climate change

2.11 Urban heat island effect


3 Thermal properties of building structures

3.1 Introduction

3.2 Notation

3.3 Heat losses from buildings

3.4 Roofs1

3.5 Ground floors and basements

3.6 Windows

3.7 Thermal bypasses

3.8 Linear thermal transmittance

3.9 Non-steady-state thermal characteristics


Appendix 3.A1: Moisture content of masonry materials

Appendix 3.A2: Thermal conductivity and thermal transmittance testing

Appendix 3.A3: Heat transfer at surfaces

Appendix 3.A4: Seasonal heat losses through ground floors

Appendix 3.A5: Application of the combined method to multiple layer structures

Appendix 3.A6: Calculation method for admittance, decrement factor and surface factor

Appendix 3.A7: Properties of materials

Appendix 3.A8: Thermal properties of typical constructions

4 Ventilation and air infiltration

4.1 Introduction and the role of ventilation

4.2 Ventilation and air quality

4.3 Ventilating heat loss

4.4 Ventilation systems

4.5 Natural and mixed mode ventilation

4.6 Methods for estimating air infiltration and natural ventilation


Appendix 4.A1: Basic pressure coefficient data

Appendix 4.A2: Summary of measured air leakage data

Appendix 4.A3: Air infiltration development algorithm (aida)

5 Thermal design, plant sizing and energy conservation

5.1 Introduction

5.2 Notation

5.3 The role of standards

5.4 Relationship to the design process

5.5 Design calculation quality plan

5.6 Thermal response

5.7 Calculation methods for thermal design

5.8 Heating plant sizing

5.9 Cooling plant sizing

5.10 Summertime temperatures in buildings

5.11 Building energy demand


Appendix 5.A1: Overview of calculation methods

Appendix 5.A2: Equations for determination of sensible heating and cooling loads

Appendix 5.A3: calculation of operative and mean radiant temperatures

Appendix 5.A4: Banded weather data

Appendix 5.A5: Glass and glazing systems

Appendix 5.A6: Example calculations

Additional appendices

6 Internal heat gains

6.1 Introduction

6.2 Benchmark values for internal heat gains

6.3 Occupants

6.4 Lighting

6.5 Personal computers and office equipment

6.6 Electric motors

6.7 Cooking appliances

6.8 Hospital and laboratory equipment

6.9 Heat gain from laboratory animals

6.10 Domestic appliances and equipment


Appendix 6.A1: Rate of heat gain from restaurant/cooking equipment

7 Moisture transfer and condensation

7.1 Introduction

7.2 Notation

7.3 Psychrometry of water vapour in air

7.4 Moisture content of materials

7.5 Mechanisms of moisture movement

7.6 Surface condensation and mould growth

7.7 Interstitial condensation

7.8 Inside and outside design conditions

7.9 Condensation calculations

7.10 Control of condensation


8 Health issues

8.1 Introduction

8.2 Thermal discomfort and health implications

8.3 Humidity

8.4 Air quality and ventilation

8.5 Visual environment

8.6 Water quality

8.7 Electromagnetic effects

8.8 Noise and vibration

8.9 Communities and health




Steering Committee

Chair: Derrick Braham (Derrick Braham Associates)

Members & authors: Brian Anderson (BRE Scotland); David Arnold (Troup Bywaters + Anders); Geoff Levermore (University of Manchester); Martin Liddament (VEETECH Ltd.); Fergus Nicol (Oxford Brookes University); Marialena Nikolopoulou (University of Kent); Foroutan Parand (AECOM); Chris Sanders (Glasgow Caledonian University); David Williams (Parsons Brinckerhoff Ltd.); Runming Yao (University of Reading)

Authors, contributors and other acknowledgements: Brian Anderson (BRE Scotland); Wayne Aston (Keysource Ltd.); Paul Baker (Glasgow Caledonian University); Colin Biggs (Nuaire Ltd); John Bradley (Positive Ventilation Ltd.); Kelly Butler (BEAMA Ltd.); Derek Clements-Croome (University of Reading); Robert Cohen (Verco); Matthew Colin (MC Building Physics); Malcolm Cook (Loughborough University); Richard Cowell (Arup); Yudish Dabee (Mott MacDonald); Michael Davies (University College London); Jill Dixon (Met Office); Sean Doran (BRE); Tim Dwyer; Matthew Eames (University of Exeter); David Fisk; John Fullwood (Met Office); Eulalia Jadraque Gago (University of Granada); Teresa Goodman (NPL Management Ltd.); Mehreen Gul (Heriot Watt University); Vic Hanby (De Montfort University); Mike Holland (Advanced Air Ltd.); Michael Holmes (Arup); Nick Howlett (Titon); Michael A Humphreys (Oxford Brookes University); Steve Irving; David Jenkins (Heriot Watt University); Mark Jentsch (Bauhaus-Universität, Weimar); Phil Jones (Welsh School of Architecture, Cardiff University); Haroon Junaidi (Adam Smith College, Glenrothes); Ludmilla Kosmina (BRE); Maria Li (Troup Bywaters + Anders); David Loe (lighting consultant); Frank Mills (Sinclair Knight Merz); Andrew Moore (Health and Safety Executive); Tariq Muneer (Napier University); Anastasia Mylona (CIBSE); Catherine Noakes (University of Leeds); Malcolm Orme (AECOM); John Parkinson (University of Manchester); Bob Peters (London South Bank University); Gerry Pettit (CBA); Peter Raynham (University College London); Peter Rogers (Cole Jarman); David Ross (AECOM); Paul Ruffles (Lighting Design & Technology); John Shelton (AcSoft Ltd.); Annalisa Simonella (Loud1Design Ltd.); Peter Tragenza (Sheffield University); Dane Virk (University College London); Richard Watkins (University of Kent); Mike Wilson (University of Westminster); Darren Woolf (Hoare Lea/Loughborough University); Andrew Wright (De Montfort University); Bill Wright (Wright Energy and Environment Ltd.)