The Building Scotland Regulations 2004

1
The Building (Scotland) Regulations 2004

• 2007 Revisions
• to
• Section 1 Structure
• Alec Millar

2
Little LARGE

• Single family dwelling
• PetronasTowers
• 452 m high
• 88 Floors

3
Coverage

• Standard 1.1 Structure
• Standard 1.2 Disproportionate Collapse
• Domestic/Non-domestic variations
• Small Buildings Structural Guidance

4
1.0 Introduction

• Background
• Latest changes
• Alternative approaches
• Eurocodes alongside BSs 2007-2010

5
Non-domestic relevant legislation

• Safety of Sports Grounds Act 1975
• Fire Safety Safety of Places of Sport Act 1987
• Guide to Safety at Sports Grounds
• Civic Government (Scotland) Act 1982
• Institution of Structural Engineers publications

6
Revised Standard 1.1 Structure

• Every building must be designed and
• constructed in such a way..,taking into account
  the nature of the ground, will not lead to
• (a) the collapse .of the building
• (b) deformations which would make the building
  unfit for its intended use, unsafe , or cause
  damage to other parts of the building...
• (c) Impairment of the stability of any part of
  another building

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Nature of the ground
8
Stability of another building

• Ground water
• lowering

• Increased foundation loads

New large building
Existing small building
W
W
Pressure bulb from W
Pressure bulb from W
Additional settlement
Lowered water table
9
Standard 1.2Disproportionate Collapse

• Every building must be designed and
• constructed in such a way that in the
• event of damage occurring to any part
• of the structure of the building the
• extent of any resultant collapse will
• not be disproportionate to the original
• cause.

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What is Disproportionate Collapse ?

11
What is Accidental Overloading ?
12
New Disproportionate Collapse Guidance

• Covers all buildings
• Risk based methodology
• Based on Structural Eurocode 1 Part 1-7
  Accidental Actions
• Updated British Standards

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Risk Based Approach

• Determine Building risk group
• Assess additional measures
• Design additional measures

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1.2.2 Domestic Risk Groups

• Houses max 4 storeys
• Garages/conservatories
• 2A Houses 5
  storeys
• Flats maisonettes max 4 storeys
• 2B Flats maisonettes 5- 15 storeys
• Buildings exceeding above limits

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1.2.2 Non-domestic Risk Groups

• Agricultural buildings
• 2A Hotels/ Offices max 4 storeys
• Shops max 3
  storeys
• Educational buildings max 1 storey
  
• 2B Hotels/ Offices/Shops max 15 storeys
• Hospitals max 3
  storeys
• Buildings exceeding above limits
• Grandstands gt 5000 spectators.

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1.2.3 Assess Additional Measures

• RG1 No additional measures
• RG2A Horizontal Ties
• RG2B Horizontal Vertical Ties
• or
• Max collapse area 15/ 70 m2
• RG3 Systematic risk assessment

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Risk Group 2A Horizontal Ties
18
Risk Group 2B Vertical Horizontal Ties
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Risk Group 2B Limits of Collapse

• Plan
  Elevation

Max collapse area Lesser of 15 or 70m2 not
beyond adjacent storeys
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1.2.5 Other sources of guidance

• National House Building Council
• UK Timber Frame Association
• Brick Development Association
• Steel Construction Institute

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Questions on Section 1
Cheryl Brolly 01506 600444 Alec Millar 01506
600426
cheryl.brolly_at_sbsa.gsi.gov.uk
alec.millar_at_sbsa.gsi.gov.uk
22
Small Buildings Guide

• Last revised June 1994
• Standards outdated
• Outdated construction
• Not accessible
• Prescriptive wording

23
Small Buildings Structural Guidance (SBSG)-
General

• Current BSs and BS ENs
• Rewritten as Guidance
• Within Domestic Technical Handbook
• Houses only
• Key factors
• Referral to specialists

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SBSG Latest Technical Changes

• Extra Geotechnical Foundation guidance
• Ground level differences
• Wall Ties
• New Wind and Snow Loads
• Timber Frame Walls
• Updated Timber Span Tables

25
New Snow Wind Maps

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Annex 1.A General

• Introduction
• Separate annexes
• Timber frame walls
• Overall scope
• 3 storey masonry
• 2 storey timber frame
• Overall flow chart
• Explanation of terms

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Annex 1.B Stability

• Expanded recommendations
• Robust 3D box structure
• Roof bracing

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Annex 1.C Foundations

• Strip foundations Stepped
  foundations

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Extra Foundations Guidance

• Eccentric Building
  Extensions

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Annex 1.D Masonry Wall heights
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Annex 1.D Masonry Walls

• Wall ties for wider cavities
• Stainless steel or non-ferrous wall ties
• Masonry strengths and diagrams
• Ground level differences

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Single storey, single leaf buildings

• Restricted to
• domestic extensions and
• within curtilage of dwelling
• More detailed diagrams on openings
• and piers and limitations

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Annex 1.E Timber Frame Walls

• Target users
• Limited to 2 storey houses
• 2.7m max panel height
• Masonry outer leaf
• Similar to Annex 1.D layout

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Timber member sizing
35
Wall sheathing
36
Example Site building data
37
Example Altitude/distance ß
38
Example- Racking resistance
39
Example- Internal walls
40
Example- Loadings
41
Example -Wall Studs
42
Example- Cripple Studs Lintels
43
Construction materials
44
Fabrication/composite action
45
Openings, notching drilling
46
Differential Movement

• Key factors
• Vertical movement
• Timber masonry
• Platform frame construction

47
Annex 1.F Timber Span Tables

• Grade C16 C24
• Notching drilling
• Dead load guidance
• Updating of flat roof floor joist tables
• Limited cut roofs

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Miscellaneous
49
Summary

• Standard 1.1 Structure
• - Nature of ground
• Stability of another building
• Standard 1.2 Disproportionate Collapse
• Domestic Non-domestic differences
• Small Buildings Structural Guidance

50
Questions on SBSG
Cheryl Brolly 01506 600444 Alec Millar 01506
600426
cheryl.brolly_at_sbsa.gsi.gov.uk
alec.millar_at_sbsa.gsi.gov.uk