Design and Specification

Question 1

What is Modern Methods of Construction

Answer 1

‘Modern Methods of Construction’ (MMC) is a wide term, embracing a range of offsite manufacturing and onsite techniques that provide alternatives to traditional house building.

Question 2

What are some examples of Modern Methods of Construction

Answer 2

• Modular construction whereby three-dimensional units are produced in a factory
• Non-structural pods (typically fully-fitted kitchens or bathrooms) which are incorporated within load-bearing structures;
• Panelised systems which are transported to site as flat panel units.
• Sub-assemblies and components such as roof frames and floor cassette

Question 3

What are some key peices of documentation relating to Modern Methods of Construction

Answer 3

2005 - The National Audit Office published ‘Using modern methods of construction to build homes more quickly and efficiently’

2017 - The National House Building Council (NHBC) launched an online MMC hub.

2018 - a forward-thinking solution to the UK housing crisis

Question 4

What is the RICS report a forward-thinking solution to the UK housing crisis

Answer 4

The RICS has released a paper calling on government and the construction industry to embrace Modern Methods of Construction (MMC)

Question 5

What are some Criticisms of Modern Methods of Construction

Answer 5

• Difficulty of defining the precise meaning of ‘modern methods of construction’
• A shift in risk - All risk will lie with one or two cotractors rather than a series of smaller contractors especially with modular units.
• The House of Lords Science & Technology Committee enquiry “undermine investment in British Manufactured masonry products that are preferred by consumers”
• Chemistry building at the University of Nottingham fire a fire occoured when the building was 70% complete. Gaps between the modular units were identified as being a factor as to why the fire was not contained

Question 6

What is cross laminated timber

Answer 6

CLT is planed and kiln-dried to reduce moisture content, then stacked into layers at 90 degrees to the layer below, gluing the lamellas together. CLT has been in use since the mid-1990s. There are some variations of this including dowel laminated timber, panels and beams.

Question 7

What are some advantages of CLT compared to steel or concrete

Answer 7

Lightweight - CLT is approximately 720kg/m3 whereas concrete is approximately 2400 kg,

Reduced carbon - Embodied Carbon +976 tonnes CLT , +2,000 tonnes Concrete of a CLT flat,

Larger spans - Used for sportcenters such as Richmond Olympic Oval and bridges such as Accoya Glulam Bridge at Sneek

Question 8

What is a universal beam

Answer 8

A Universal Beam is primarily used a horizontal load bearer. The section is often taller than a Universal column.

Question 9

What is a universal column

Answer 9

A column is designed to support a compressive load. The web section is similar or equal in width and height to the flange sections. The web is a bit thicker in a column. Meaning it can be used as a beam.

Question 10

What is a Rolled steel Joist

Answer 10

Traditionally specified before BS 4-1:2005 Hot rolled rather than extruded. This can be identified by slightly slopped flanges due to manufacturing process.

Question 11

What is Modular construction

Answer 11

‘Modular construction’ is a term used to describe the use of factory-produced pre-engineered building units that are delivered to site and assembled as large volumetric components or as substantial elements of a building

Question 12

What are the benifits to Modular construction

Answer 12

Safer Construction - Eliminates most onsite hazards due to being mostly off site. The only significant hazard remaining is working at height.

Reduced Construction Schedule

Reduced Waste - When building in a factory, waste is eliminated by recycling materials, controlling inventory and protecting building materials

Improved Air Quality - completed in a factory-controlled setting using dry materials, the potential for high levels of moisture being trapped in the new construction is eliminated.

Imporved Qulaity Assurance - Achieved through repetition, inspection and operating in a factory-controlled environment

Question 13

What are the disadvantages to Modular construction

Answer 13

Smaller Rooms - Due to the limatitions of transportations the room sizer are limited

Transportation Challenges - Difficulty transporting and handling modules due to their large weight and size can be costly and challenging within the confines of a small constructioin site.

No design changes - Due to the nature of modular construction alterations are near impossible and expensive.

Question 14

What are the types of load on a building

Answer 14

Dead loads refer to the structure’s self weight and generally remain constant during the structure’s life.

Live loads, Live loads, also known as imposed loads, are usually temporary, changeable and dynamic. These include loads such as vehicle traffic, occupants, furniture and other equipment.

Enviromental loads

Question 15

What are enviromental loads

Answer 15

Wind loads may not be a significant concern for small, massive, low-level buildings, but it gains importance with height, the use of lighter materials and the use of shapes that my affect the flow of air, typically roof forms.

Snow Loads are calculated by the projections made by snow at different parts of the structure, The amount of snow load depends on the height of building, size & shape of the roof, the location of building e.t.c

Earthquake Significant horizontal loads can be imposed on a structure during an earthquake. Buildings in areas of seismic activity need to be carefully analysed and designed to ensure they do not fail if an earthquake should occur.

Thermal loads All materials expand or contract with temperature change and this can exert significant loads on a structure. Expansion joints can be provided at points on long sections of structures such as walls and floors.

Ground movement such as heave and settelment can be design out by IS 1904 (1986): Code of practice for design and construction of foundations in soils.

Question 16

How are loads catagorised

Answer 16

Concentrated loads (or point loads): Single loads that act over a relatively small area, such as column loads.

Line loads: Loads exert a load along a line, such as a partition’s weight on the floor.

Distributed (or surface) loads: These exert a load over a surface area, such as the weight of floors and roofing materials.

Question 17

What are grades of OSB

Answer 17

OSB 1 - General purpose boards for furniture
OSB 2 - Load-bearing boards for dry use
OSB 3 - Load-bearing boards for wet use
OSB 4 - Heavy-duty load-bearing boards for wet use

Question 18

What is OSB

Answer 18

An engineered wood-based panel consisting of three tiers of timber strands. (The outer 2 are orientated one way and the inner layer at 90 degrees to that)

Question 19

What types of waterproofing systems are there

Answer 19

BS 8102:2009 indentifies three types;

• Type A - Barrier protection
• Type B - Structurally intergrated protection
• Type C - Drained protection

Question 20

What are some considerations for concrete repair

Answer 20

Impact on surrounding area - sand blasting
Weather - wind, temperature, rain
Contamination - marine environment
Rienforcement protection - corrosion inhibitor

Question 21

What are some considerations when specifying cavity barriers

Answer 21

Heat loss - meet part L
Water ingress - wind driven rain, surface grooves
Fire protection - 30 min fire barrier
Cavity width - cut on site for varying widths
Sustainablility - minor impact on SAP calculation
Zero maintenance

Question 22

What are some considerations when specifying stair nosings

Answer 22

Profile - bull nose/rake/straight
Slip resistant - classification high/moderate/low
Floor covering - carpet/vinyl/ none
Colour - specified light reflectance value (contrasting)

Question 23

What are some considerations when specifying roof lights

Answer 23

Use class - 3, fragile. 0, unrestricted access
Sound reduction - double/triple glazing
Thermal performance 
Slip resistance 
Testing method - hard body/soft body

Question 24

What are some considerations when specifying EWI

Answer 24

Thermal performance - insulation thickness
Substrate - load bearing capacity, anchors, wind
Location - Marine enviroment, Galvinized mesh
Fire - Building height
Colour

Question 25

How do you ensure Legislative compliance

Answer 25

Adhere to the following peices of legislation;

• The Town and Country Planning Acts
• Public health (BuildingRegulations)
• Construction (Design and Management) Regulations
• Control of Asbestos Regulations 2012

Question 26

How would you check if a material is hazardous

Answer 26

Refer to the product data sheet. Failingthat contact the manufacturer directly.

Question 27

What is RIBA Stage 0 Strategic definition

Answer 27

The client’s business case and strategic brief are assessed to ensure they have been properly considered’ and the scope of the project is defined.

Question 28

What is RIBA Stage 1 Preparation and briefing

Answer 28

Involves developing the information that the design team will need to commence the design process at Stage 2. Broad specification is provided by the client such as;

• Space requirements
• Outline budget cost
• Quality asperations
• Time requirements

Question 29

What is RIBA Stage 2

Answer 29

Outline specifications including;
The design concept.
Outline specifications.
Schedules of accommodation.
A planning strategy.
The cost plan.
Procurement options.
Programme and phasing strategy.
Buildability and construction logistics.

Question 30

What is RIBA Stage 3 Spatial coordination

Answer 30

It suggests that a spatially coordinated design is a: ‘Design in which the client’s Spatial Requirements and the spaces required for any Building Systems;

• Plant and M&E space allocation
• Structural design
• Internal layout

Question 31

What is RIBA Stage 4 Detailed design

Answer 31

Develop stage 3 without major spatial amendments including;

• Accoustic requirements
• Dimensions
• Fire requirements
• Aestetic requirements
• Thermal performance
• Corrosion resistance requirements
• Moisture resistance requirements
• Relevant standards
• Manufacturers and Products
• Workmanship standards

Question 32

How do you produce specifications

Answer 32

We produce specifications using a software called NBS Chorus.

It allows you to select CAWS for example M60 finishes, K10 linings, C20 demolition.

It allows you to remove works sections that are not required by “parking them”.

It automatically includes extracts from British standards for example when specifying the finish of sandblasting metal the drop-down menu will let you select from Sa1, Sa2 and Sa3.

Chorus also has a directory of products and manufacturers.

The software also allows multiple users to edit a specification at one time, allowing for simple quality assurance.

Question 33

What is an outline specification

Answer 33

An outline specification is a brief description of the main components to be used in construction. They should be described in sufficient detail to allow the cost consultant to prepare some approximate quantities. The components are broad such as;

• Cladding
• Substructure
• Flooring
• Roofing
• Ceilings

Question 34

What is an Output-based specification

Answer 34

The output-based specification may be a development of the project brief, but it is separate from it as it defines only the outputs that are required from the project, it does not attempt to address how those outputs might be achieved.

Question 35

What are some comon specification errors

Answer 35

• Referring to clause numbers on drawings can see that the contractor disregards various workmanship clauses.
• Specifying temporary works as this is the responsability of the contractor as temporary works coordinator
• Using the term ‘or similar approved’ in a specification. If you approve it you are assuming liability for it. Instead use the term ‘or acceptable equivalent’
• Name a very specific product and then provide performance characteristics for that product. It is not necessary and creates the potential for conflict resulting in claims.
• Always create a new specification for each project as standards, materials and best practice are consistently chaning.

Question 36

What are perspective specifications

Answer 36

General requirements relating to regulations and standards.
The type of products and materials required.
The execution and installation methods required.

Question 37

What are perfromance specifications

Answer 37

Performance specifications describe the result that is required from particular items and leave it to the contractor or supplier to satisfy that requirement. In effect it requires the contractor or supplier to complete the design.

Question 38

What is the difference between perspective and performance specifications

Answer 38

Perspective - Specifies products and manufactures with workmanship and regulatory standard clauses

Performance - Requirements are specificed and the contractor puts fourth products that meet the requirements.

Question 39

What is CAWS

Answer 39

Common Arrangement of Work Sections developed by the Construction Project Information Committee (CPIC), to address inconsistencies in specifications at the time. It works on a Letter and number system e.g.

A - Preliminaries
B - Complete buildings / structures / units
C - Demolition / Alteration /Renovation
D - Groundwork

NBS is beginning to move away from CAWS in favour of the Uniclass system.

Question 40

What is Uniclass system

Answer 40

Uniclass is a voluntary classification system for the construction industry that can be used to organise information throughout all aspects of the design and construction process and designed to be BIM level 2 compatible. It works on a XX-00-00-00 system to identify not only specification items but drawings, reports and cost informaiton.

Question 41

How would you size a room

Answer 41

In accordance with Technical housing standards - nationally described space standard

Question 42

What are some changes to the 2020 Plan of Work

Answer 42

The green overlay has been adopted into the main plan.

Stage 2 Preparation and brief were changed to Preparation and briefing to demonstrate that the brief is an ever-evolving document.

Stage 3 changed developed design to spatial design. To show it’s not changing the concept but coordinating the spaces.

the 2013 guide was unclear when planning permission should be submitted 2-4 the 2020 plan clearly states at the end of stage 3.

Stage 5 changed to manufacturing and construction from construction as I now recognise modern methods of construction such as offsite manufacturing and offsite construction.

Question 43

What are the plan of work stages

Answer 43

Stage 0 - Strategic definition
Stage 1 - Preparation and briefing
Stage 2 - Concept design
Stage 3 - Spatial coordination
Stage 4 - Technical design
Stage 5 - Manufacturing and construction
Stage 6 - Handover
Stage 7 - Use

Question 44

what is a u-value

Answer 44

Thermal transmittance, also known as U-value, is the rate of transfer of heat through a structure, divided by the difference in temperature across that structure.

Question 45

What does the number after FD on a fire door represent

Answer 45

The minimum level of resistance to smoke/fire for a specified number of minutes. Typically 30, 60, 90, 120.

Question 46

What is the Technical housing standards - nationally described space standard

Answer 46

The document sets out the minimum Gross Internal Areas for new dwellings. It takes into account Number of stories, number of bedrooms, built-in storage and number of bed spaces.

Question 47

What is BS EN 1504

Answer 47

BS EN 1504 - Products and systems for the repair and protection of concrete structures

Question 48

What are BS EN 1504-9 10 “principles” for the repair and protection of concrete structures

Answer 48

1. Protection against ingress
2. Moisture control
3. Concrete restoration
   4-5. Structural strengthening
4. Resistance to chemicals
5. Preservation or restoring passivity
6. Increasing resistivity
7. Cathodic control
8. Cathodic protection.