Construction Tech

Question 1

Tell me about a time you gave your client advice on a design solution

Answer 1

On the Cricklewood project during the pre construction phase, the delivery team needed to assess the condition of the roof.

The building was 4 storeys high so it posed implications how to go about carrying out the roof survey.

I presented two options that can be used to assess the roof.

1. Setup scaffolding, around the perimeter of the building. During the construction phase this would be erected regardless, but by doing this now the scaffolding would be set up earlier. However I had to consider value for money in this instance. The scaffolding would take a long time to erect just for a roof survey, it would be costly and between the design and construction stage the scaffolding cost would be inefficient due to it being unused
2. Another option I considered was making a use of drone surveys, which were much cheaper, quicker to setup and the health and safety associated with drones over scaffolding was safer. However drone surveys were prone to weather conditions, and the quality was lower compared to assessing in person.

I presented a comparison between the two and weighed up the pros and cons to my client and ultimately chose to use the drone surveys.

Question 2

What are the advantages and disadvantages of using drones to carry out site surveys?

Answer 2

Advantages:
Fairly safe to use
Quick and easy
Cheaper over scaffolding

Disadvantages:
Low quality
Prone to weather conditions

Question 3

How did you estimate the cost of scaffolding vs surveys? How did you measure the building?

Answer 3

NRM tends to deal with scaffolding as number per weeks so by utilising previous quotes I worked out the average rate per square meter to adjust it for the size of the building.

I also consulted our framework contractors to confirm the figure is within a suitable range and presented it as a range.

For drone surveys I found an estimate of £1200 from a previous project.

Question 4

With regards to your site visit on Mercury House, how did this impact your understanding of the construction methods?

Answer 4

Cricklewood allowed me to understand the level of surveys required for maintaining the asthetic of the building

Internal and external scaffolding and the time it takes to put those up. I think it took 4 weeks to even prepare it

I got a good understanding of flat roofs

Question 5

How did extending the project timeline impact project? budgets?

Answer 5

This obviously increased prelims by two weeks and therefore the cost. I believe the weekly cost was under £5,000 which included project management and scaffolding

I effectively had to consider a whole life cycle cost rather than just construction

Question 6

What is substructure?

Answer 6

All elements of work that are undertaken below the damp proof course that provides the basis for the
superstructure to be constructed upon.

Question 7

What are the Building Regulations

Answer 7

Regulations that set out the minimum performance standards for the design and construction of buildings.

Question 8

What are the approved documents?

Answer 8

A. Structure.-Provides guidance on ensuring that the structure of a building is robust and stable.

B. Fire safety. - Covers fire safety measures in buildings, including means of escape, fire resistance of materials and structures, and fire detection and alarm systems.

F. Ventilation. - Offers guidance on providing adequate ventilation within buildings to maintain air quality and prevent issues such as condensation and mold growt

H. Drainage and waste disposal. - Covers requirements for sanitation facilities, hot water systems, and water efficiency measures in buildings.

Question 9

What is superstructure?

Answer 9

All internal and external works items above the damp proof course.
This is made up of:
o External walls.
o Stairs.
o Roof.
o Structural walls.
o Suspended ceilings.
o Raised floors.

Question 10

What are the typical components of site investigations?

Answer 10

Their objective is to collect and record data to help with the design and construction process. This should include matters in relation to the site that may impact the development for example:-
o Boundary hedges & fencing.
o Existing trees.
o Size, depth and location of services including gas, telephone, electricity, water & drains.
o Existing buildings.
o Ground water conditions.
o Soil investigations.
o Trial pit information.

Question 11

What is the purpose of soil investigations?

Answer 11

• Their purpose is to determine the suitability of the site for the proposed works and determine adequate and economic foundation design.
• The investigation should determine the potential difficulties associated with the ground conditions and assist with identifying a suitable foundation solution.

Question 12

What are temporary works?

Answer 12

Temporary works do not normally appear on construction drawings but may be required depending on the construction methodology being used.

Temporary works may also be required as a result of health and safety requirements to ensure a safe method of construction

Question 13

What temporary works are you aware of?

Answer 13

Scaffolding
Cranes
Shoring

Question 14

What is a scaffold?

Answer 14

• Scaffold is a temporary working platform erected around the perimeter of a building or structure to
  provide a safe working place at a convenient height.
• Scaffold is usually required for work 1.5m above ground level.

Question 15

What is shoring?

Answer 15

• Shoring is a form of temporary support given to existing buildings.
• Its purpose is to provide a precaution against damage or injury due to collapse of the structure.

Question 16

What is a borehole?

Answer 16

• Any shaft drilled into the ground vertically or horizontally
• A borehole can be used for soil investigation or for geothermal heating solutions.
• Boreholes are the most suitable method of soil investigation when foundations are over 3m deep.

Question 17

What are piles?

Answer 17

Piles transfer loads from the structure to the ground, helping to support it. Pile foundations are often used where the ground is too weak to underpin the structure.

Question 18

What are the different types of piles?

Answer 18

Sheet piles.
* Quite literally metal sheets are inserted into the ground vertically and concrete can be poured in.
* A deep trench is excavated and concrete is poured in situ.
* The piles can be used to form basement walls or act as retaining walls.

Bored Piles.
* Soil is exacavated vertically and then concrete is porued in. This can also be reinforced concrete.

Pre-cast piles.
* Piles are hammered into the ground. This is not often favoured due to the high noise levels associated with installation and the lack of flexibility in terms of depth required.

Question 19

What is a strip foundation?

Answer 19

• Strip foundations are formed by creating a shallow continuous excavation to support the perimeter and internal walls.

Question 20

What are the technical advantages of steel frames?

Answer 20

• Steel frames are often quicker to assemble in comparison to alternative methods.
• They are 100% recyclable and inorganic meaning they will not warp, split, crack or creep.
• They offer the highest strength to weight ratio of any building material.
• Steel frames are not vulnerable to termites or any type of fungi or organism.
• They are dimensionally stable and do not expand or contract with moisture or temperature changes.
• Due to strict manufacturing controls, consistent material quality can be obtained due to production
  taking place in line with strict standards.
• Steel is non-combustible so it will not contribute to the spread of a fire.
• Steel frames are lighter in comparison to concrete frames and will often benefit from a cheaper
  foundation solution.

Question 21

What are the technical disadvantages of steel frames?

Answer 21

• Steel frames require fire protection to be retrospectively installed.
• Fixing components may require replacement over time.
• The price of steel often fluctuates and can result in a lack of cost certainty.
• Installation of steel frames requires experienced builders at an additional cost. Resources can also be
  difficult to acquire depending on market conditions.

Question 22

What are the technical advantages of concrete frames?

Answer 22

• Fire protection is often provided inherently as part of the structure.
• Maintenance requirements associated with concrete frames are relatively low in comparison to alternative methods.
• Concrete frames often provide good sound and heat insulation properties in comparison to steel frame constructions.

Question 23

What are the technical disadvantages of concrete frames?

Answer 23

• In comparison to steel frames, they are more time consuming to install.
• There may also be complications during the install resulting from colder and inclement weather
  conditions.
• The need for steel reinforcement can lead to issues around price fluctuations and cost uncertainty
  associated with steel frames.
• Concrete frames are often heavier and require larger foundations.

Question 24

What type of building work is covered by the Building regulations?

Answer 24

• The Erection or extension of a building.
• Installation or extension of a service that is controlled by the regulations.
• Alteration projects which will temporarily or permanently affect the building in terms of structure, fire & access.
• Insertion of insulation into cavity walls.
• Underpinning building foundations.

Question 25

Can you explain the key stages outlined in the RIBA Plan of Work 2020 and how they structure the design and construction process?

Answer 25

Stage 0 - Strategic definition

Stage 1 - Preperatation and briefing

Stage 2 - Concept design

Stage 3 - Spatial coordination

Stage 4 - Technical design

Stage 5 - Manufacturing

Stage 6 - Handover

Stage 7 - Use

Question 26

In Stage 2 (Concept Design), how do you contribute to the development of initial design concepts? Can you share an example where the concept design phase significantly influenced the project outcome?

Answer 26

You prepare an initial cost estimate

Question 27

Can you elaborate on your decision to recommend drone technology for assessing the condition of the roof in Cricklewood? How did you assess the effectiveness of drones compared to traditional methods like scaffolding?

Answer 27

I considered the safety, speed and value for money.

Scaffolding would allow consultants to carry out various of surveys perhaps however the time associated with erecting the scaffolding,

Drones were significantly cheaper and quicker

Question 28

When the contractor discovered irreparable damage to the windows at Cricklewood, you proposed extending the project timeline for window replacements. How did you communicate this solution to the project manager, and what considerations were involved in determining the long-term cost-effectiveness of this approach?

Answer 28

I presented this in two scenarios.

First scenario I presented the risk of not fully replacing the windows, where long term they could be damaged again which would require scaffolding and site access and this could disrupt site operations

The second scenario I presented to the client was the higher costs of UPVC windows being fully replaced and therefore the extension of programme cost associated with this.

Question 29

What is an external envelope?

Answer 29

• The materials and components that form the external shell or enclosure of a building.
• These may be load or non-load bearing.

Question 30

What is the difference between bored vs pre-cast piles?

Answer 30

• Bored piles are defined when the process for removing the spoil to form the hole for the pile is carried
  out by a boring technique.
• They are used primarily in cohesive subsoils for the formation of friction piles and when forming pile
  foundations close to existing buildings where the allowable amount of noise and/or vibration is limited.
• Pre-cast Concrete piles are generally used where soft soil deposits overlie firmer strata. These piles are
  usually driven using a drop or single action hammer.
• Issues can arise due to the noise levels associated with the installation method of pre-cast piles.

Question 31

What are pad foundations?

Answer 31

• Pad foundations provide a base for reinforced concrete or steel columns.
• They are usually formed by making an isolated excavation in the shape of a square or rectangle.
• They often have reinforcement mesh as part of the construction and spread the load to a layer of
  bearing soil or rock below.

Question 32

What are retaining walls?

Answer 32

• They act as an earth retaining structure for the whole or part of their heights.
• They are used to support and retain soils laterally so that it can be retained at different levels on the two
  sides.
  *Retaining walls are structures built to hold back soil or other materials and prevent erosion or slope instability. They are commonly used in landscaping and civil engineering projects to create level surfaces or terraces on slopes, prevent landslides, or create usable space in areas with uneven terrain

Question 33

What is form work?

Answer 33

Formwork, also known as shuttering or molds, is a temporary structure or mold into which concrete or other materials are poured to create a specific shape or structure.

Question 34

What is the Building Act 1984?

Answer 34

The Building Act 1984 is a central piece of legislation which sets out the legal framework for the construction, alteration and maintenance of buildings in England and Wales

Question 35

What is the Town Country Planning Act 1990?

Answer 35

This legislation deals with the roles and responsibilities of planning authorities, such as local authorities and national park authorities
development control, including planning permission, development orders, determination of applications, appeals, major infrastructure projects
enforcement, including enforcement and stop notices
*trees, including tree preservation ordersThis legislation deals with the roles and responsibilities of planning authorities, such as local authorities and national park authorities
development control, including planning permission, development orders, determination of applications, appeals, major infrastructure projects
enforcement, including enforcement and stop notices
*trees, including tree preservation orders

Question 36

Talk me through why you advised your client on doing a full window replacement?

Answer 36

I effectively carried out a life cycle cost.

I considered the maintenance associated if the window wasn’t replaced which would include further repairs such as simply painting over it and filling out the rotten gaps and the scaffolding associated with this

I considered simply paying the price now for a full replacement which required additional two weeks of scaffolding and more prelims for the contractor but long term it wouldn’t require maintenance

Question 37

What type of windows were they and what measurements were they?

Answer 37

These were UPVC windows

Question 38

What derisking activities did the contractor undertake on P Programme?

Answer 38

These were intrusive surveys by digging out the soil and examining if it is suitable to build the components of P Programme.

Question 39

What are environmental surveys?

Question 40

What is the difference between bored vs. pre-cast piles?

Answer 40

• Bored piles are defined when the process for removing the spoil to form the hole for the pile is carried
  out by a boring technique.
• They are used primarily in cohesive subsoils for the formation of friction piles and when forming pile
  foundations close to existing buildings where the allowable amount of noise and/or vibration is limited.
• Pre-cast Concrete piles are generally used where soft soil deposits overlie firmer strata. These piles are
  usually driven using a drop or single action hammer.
• Issues can arise due to the noise levels associated with the installation method of pre-cast piles.

Question 41

Describe a pitched roof detail

Answer 41

• Pitched roofs typically are made up of rafters which span from the apex of the roof and are fixed to the
  top of the external wall by a wall plate.
• At the apex of the roof are the ridge tiles which are supported by the ridge board.
• The roof covering whether slate or concrete tiles are typically fixed to roof battens.
• Supporting the rafters and roof coverings are the struts, purlins and roof beams.
• A soffit and eaves board may be fixed to the end of the rafters along with the guttering and rain water
  goods.
• Vent tiles may also be used to provide natural ventilation to the roof space

Question 42

What are the Building Regulations Approved Documents?

Answer 42

• They provide general guidance on performance of materials expected in order to comply with the functional requirements of the building regulations & provide practical examples.
• They only provide guidance & therefore there is no obligation to adopt specific solutions if it is possible to meet requirements via a different means.