Technical Guidance Documents are published to accompany each part of the Building Regulations indicating how the requirements of that part can be achieved in practice.
Current Edition
Technical Guidance Document L - Conservation of Fuel and Energy – Dwellings (2022)
TGD L DEAP Example A (381.7 KB)
TGD L DEAP Example B (381.1 KB)
TGD L DEAP Example C (381.15 KB)
TGD L DEAP Example D (382.39 KB)
TGD L DEAP Example E (377.81 KB)
TGD L DEAP Example F (382.25 KB)
Previous Editions
Technical Guidance Document L- Conservation of Fuel and Energy – Dwellings (2021)
This document is from 2021.
Technical Guidance Document L- Conservation of Fuel and Energy – Dwellings (2019) (2.34 MB)
This document is from 2019.
Technical Guidance Document L- Conservation of Fuel and Energy – Dwellings (2017) (1.46 MB)
This document is from 2017.
Technical Guidance Document L - Conservation of Fuel & Energy - Dwellings (2011) (985.88 KB)
This document is from 2011.
Technical Guidance Document TGD PartL - Conservation of Fuel and Energy - Dwellings (2007) (1.73 MB)
This document is from 2007 and was reprinted in 2008.
Technical Guidance Document L - Conservation of Fuel and Energy Dwellings (2002) (696.1 KB)
This document is from 2002 and was reprinted in 2005.
Technical Guidance Document L - Conservation of Fuel and Energy (1997) (1.28 MB)
This document is from 1997.
Technical Guidance Document L - Conservation of Fuel and Energy 1991 (1.09 MB)
This document is from 1991.
Supplementary Documents
Technical and practical implications of the new Part L Dwelling & Part F 2019 - Presentation (3.2 MB)
This document is from 2019.
Heating & Domestic Hot Water Systems for Dwellings– Achieving Compliance with Part L & Energy Performance of Buildings Regs 2019 (2.2 MB)
This document is from 2019.
Acceptable Construction Details
These Acceptable Construction Details (ACDs) focus on thermal bridging and airtightness. This guide will help appropriate persons to achieve the performance standards in the Building Regulations Technical Guidance Document L 2021 – Conservation of Fuel and Energy – Dwellings.
The guide is presented in 2 Parts. Part 1 discusses the general theory of insulation continuity and airtightness in construction. Part 2, in seven separate sections, provides indicative detail drawings of thermal insulation and airtightness provisions for specific construction interfaces.
Part 1
Introduction and general theory of insulation continuity and air tightness
Acceptable Construction Details TGD PartL Building Regulations 2021- Introduction
Part 2
Acceptable Construction Details
Acceptable Construction Details TGD PartL Building Regulations 2021- Cavity Wall Insulation
Acceptable Construction Details TGD PartL Building Regulations 2021- External Wall Insulation
Acceptable Construction Details TGD PartL Building Regulations 2021- Internal Wall Insulation
Acceptable Construction Details TGD PartL Building Regulations 2021 - Timber Frame Insulation
Acceptable Construction Details TGD PartL Building Regulations 2021- Steel Frame Insulation
Acceptable Construction Details TGD Part L Building Regulations 2021- Hollow Block Insulation
Acceptable Construction Details TGD PartL Building Regulations 2021- General
Previous Acceptable Construction Details
Acceptable Construction Details TGD PartL Building Regulations 2011- Introduction (3.12 MB)
This document is from 2011.
Acceptable Construction Details TGD PartL Building Regulations 2011- Cavity Wall Insulation (6.09 MB)
Cavity Wall Insulation
Acceptable Construction Details TGD PartL Building Regulations 2011- External Wall Insulation (4.82 MB)
External Wall Insulation.
Acceptable Construction Details TGD PartL Building Regulations 2011- Internal Wall Insulation (3.71 MB)
Internal Wall Insulation.
Acceptable Construction Details TGD PartL Building Regulations 2011 - Timber Frame Insulation (3.42 MB)
Internal Wall Insulation.
Acceptable Construction Details TGD PartL Building Regulations 2011- Steel Frame Insulation (4.52 MB)
Steel Frame Insulation.
Acceptable Construction Details TGD Part L Building Regulations 2011- Cavity Block Insulation (4.03 MB)
Cavity Block Insulation.
Heating and Domestic Hot Water Systems for Dwellings (1.16 MB)
Achieving Compliance with Part L 2008
Amendment to Heating & Domestic Hot Water Systems for Dwellings (56.22 KB)
This document was published on October 29, 2008.
Acceptable Construction Details TGD PartL Building Regulations 2011- General (968.7 KB)
General Details.
This is the supporting document referred to in Par 1.4.1 of Technical Guidance Document L - Dwellings 2007. It is a source of guidance on the means of complying with the requirements of the Building Regulations for space heating systems and hot water systems.
Guide to the Condensing Boiler Installment Assessment (345.12 KB)
Procedure for Existing Dwellings.
This document contains the detailed guidance referred to in paragraph 2.2 of Technical Guidance Document L - Dwellings 2007 to assess specific situations where the provision of condensing boilers is not practicable. It is also included as an appendix in the document "Heating and Domestic Hot Water Systems for Dwellings - Achieving Compliance with Part L".
Dwellings Energy Assessment Procedure
The Dwellings Energy Assessment Procedure (DEAP) methodology required to show compliance of dwellings with Regulation L2(a) of Part L, as amended by the Building Regulations (Amendment) Regulations 2005 (S.I No. 873 of 2005), and contained in the May 2006 Edition of TGD L, can be accessed and downloaded from the Sustainable Energy Authority of Ireland's website.
The following are links to databases which also support the DEAP procedure:
