Con Tech SoE Q's

Question 1

What are the RIBA Stages of Work?

Answer 1

• 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 2

What is buildability?

Answer 2

Harnessing a contractors expertise to aid in design and construction.

Question 3

What are the types of foundations?

Answer 3

Strip foundations (strip of linear structure that spreads weight across total area of ground)

Pad foundations (usually square or rectangle and typically used to support columns)

Raft foundations (continuous slab that extends over the entire footprint of the building)

Piled foundations (a column that extends deep into the ground)

Question 4

What are the two main types of piles?

Answer 4

End bearing piles (bottom of pile rests on layer of strong rock or soil, load of building is transferred through to this layer)

Friction piles (side surface of the pile works to transfer forces to the soil by creating sheer stresses)

Question 5

What are the two main construction methods for pile foundations?

Answer 5

Bored piles (manufactured on site)

Driven concrete piles (formed off site in factory controlled conditions)

Question 6

Can you name some of the Building Regulations?

Answer 6

• Part L – Conservation of Fuel and Power
• Part M – Access to and use of Buildings

Question 7

What modern methods of construction are you aware of?

Answer 7

• Modular construction
• Timber framing
• Pre cast panels
• Utility Pods
• Bathroom Pods

Question 8

Are you able to provide me with advantages and disadvantages of MMC?

Answer 8

Advantages of MMC is that is provides higher quality, they are safer, they are quicker, and they are more sustainable.

Disadvantages are that they reduce social value, the immediate cost is high, and materials are imported from outside the UK. Undermining UK manufacturing.

Question 9

What are the advantages and disadvantages of timber framing?

Answer 9

Advantages of timber framing are that they are sustainable, lightweight and quicker to erect that traditional masonry.

Disadvantages are that they require fire protection and can be subject to dry and wet rot.

Question 10

Can you advise on the outcome of your report on timber and traditional masonry construction?

Answer 10

The outcome of the report was that timber construction was cheaper, as well as quicker to construct. The report was produced for a developer that produced their own off site timber frames.

Question 11

QS is an expert in cost and contract. Why should a QS be equipped with construction technology knowledge?

Answer 11

This is to be able to advise on whether certain techniques will be cheaper than alternatives, whilst exploring life cycle costs and whether certain materials could provide better value over time.

Further to this, we have to have an understanding of con tech when assessing interim applications to cross reference work done on site with the application.

Question 12

What is EWS1?

Answer 12

External Wall System (EWS)

EWS1 form is designed to be used for residential properties such as flats, student accommodation, care homes and HMO’s.

Is a set form that allows a building owner to confirm that an external wall system on residential buildings has been assessed for safety by a suitable expert. Includes a fire risk appraisal which is valid for 5 years.

Question 13

What is curtain walling?

Answer 13

Typically a lightweight aluminium frame with glazing infill panels

Question 14

What is rainscreen cladding?

Answer 14

A system which manages the flow of rainwater on a building, serving as a screen and protection against rain for the rest of the building

Outer protective layer of the wall buildup

Protects the backing wall, but is not 100% water resistant. Therefore, the backing wall must be.

Question 15

What advice could you give a client on the advantages / disadvantages between steel and concrete frames? What about cost advice?

Answer 15

Steel frame advantages are faster to erect than concrete frames, recyclable, beams can span over long distances (ideal for warehouses)

Steel frame disadvantages typically have lower load bearing capacity than concrete frames, may require fire protection, steel prices can be volatile, do not have same acoustic or thermal properties of concrete

Concrete frames advantages are fire protection is inherent in the structure, cladding and other finishes can be fixed directly to the frame, provides good sound and heat insulation

Concrete frame disadvantages are they require formwork, slower to construct on site, requires a bulky structure, concrete does not span as well as steel, long curing time.

Question 16

What is a raft foundation?

Answer 16

A raft foundation extends over the entire footprint of the building, transferring the load to the ground.

Typically used on lightweight structures in good ground bearing capacity.

Question 17

Why did you assume that a raft foundation would be suitable?

Answer 17

I assumed that a raft foundation would have been suitable for St Wilfrid’s as it was a lightweight single storey structure.

I originally assumed that the ground was of good ground bearing capacity as well.

Question 18

Why was piling seen as the most suitable solution on St Wilfrid’s?

Answer 18

Piling was seen as the most suitable solution as a soil investigation was undertaken by the structural engineer and it confirmed that the ground was of poor bearing capacity. This concurred with the previous investigation that had been undertaken. The structural engineer advised that piling would be the most appropriate solution.

Question 19

Was there a difference in cost between the raft and piling solution?

Answer 19

The difference in cost between the raft and piling was approximately £75,000.

Question 20

What type of piling solution was proposed?

Answer 20

Bored piling was suggested as the school is located in a built up area, surrounded by residential homes.

Driven piling would have caused too much noise and vibration.

Question 21

What is an AHU?

Answer 21

• Air Handling Unit

Question 22

What is an FCU?

Answer 22

• Fan Coil Unit

Question 23

What is the difference between an AHU and FCU?

Answer 23

An AHU operates by bringing fresh air in from the outside and disposing of exhaust air.

An FCU recirculates and conditions air in a centralised interior space.

Question 24

What are the advantages and disadvantages of FCU’s and AHU’s?

Answer 24

Advantages of FCU’s are that they are easy to install and can provide individual temperature control to each room.

Disadvantages of FCU’s are that they can be noisy on a high setting and the air filter requires maintenance.

Advantages of AHU are that they are versatile and can be used to handle a wide range of air conditioning requirements. They are also easy to maintain and service.

Disadvantages are that they have a high initial cost and require more regular maintenance than FCU’s.

Question 25

Do you know of any other mechanical ventilation solutions?

Answer 25

Variable Air Volume Temperature remains constant and the air flow varies through the system.

Question 26

How did you present the options to the client?

Answer 26

I put the varying options in a report which were presented to the client. I advised on the advantages and disadvantages and provided advice on which option to proceed with.

Question 27

What was the outcome of the cost comparison between AHU and FCU?

Answer 27

The on floor FCU’s were more expensive than the AHU’s. The FCU’s were priced at approximately £2.95m, in comparison to £2.45m for the AHU’s.

Question 28

What is modular construction and what are the benefits?

Answer 28

Prefabricated modules built off site in factory conditions Safety – hazards such as falling from height more likely to occur on site than in a factory Efficiency and quality – construction takes place in a controlled environment Sustainability – reduction in waste produced Speed – work in the factory can be scheduled to being at the same time as other activities on site, resulting in shorter build programme

Question 29

Why was the façade on Alberton House complex?

Answer 29

The façade on Alberton House was complex as it was naturally ventilated. It also had different levels of solar shading dependent on the area and angle it was facing.

Question 30

What was proposed as the most appropriate solution in relation to the façade and why?

Answer 30

The unitised system was selected as opposed to the precast system. This was following a costing exercise and it showing that the precast option was significantly more expensive, even though it had a better embodied carbon impact.

Question 31

What is a unitised façade system?

Answer 31

A lightweight aluminium structure with glazed or opaque panels fixed to the system.

Question 32

What is a precast façade system?

Answer 32

It is a façade made of bespoke precast elements.

Question 33

What are the advantages and disadvantages of façade systems?

Answer 33

Advantages of a unitised system are that there is increased safety on site as you do not need to work at height, faster installation as units are lifted into place, lightweight, and they provide good thermal performance. Disadvantages are that there can be alignment issues, they also take a while to be constructed off site and therefore you need to consider programme implications. The system requires specialized transportation and lifting equipment. Advantages of precast façade systems are that they have a high compressive strength and they can save time due to prefab off site. Disadvantages are that they are heavier than a unitised system, as well as more expensive. It is also difficult to modify a piece of precast concrete if it is slightly out of tolerance.

Question 34

Which was the most cost-effective solution in terms of the façade?

Answer 34

The most cost effective solution was the unitised system. This was around £2m cheaper than the precast option.

Question 35

What foundation designs were considered for the Llanbedrog project? What was the cost difference between them?

Answer 35

The options that were considered were a raft and strip foundation. The strip foundations were a cheaper option and it was considered a suitable solution for transferring the load of the masonry walls to the ground.

Question 36

What is a dormer?

Answer 36

A roofed structure that contains a window and projects vertically beyond the pitched roof.

Question 37

What were the differences in cost between the three options proposed by the architect?

Answer 37

The client had a budget of £300k and the first option was priced at £240k, with the second priced at £310k and the third option at £465k. I advised the client to proceed with option 1 as the third option was £165k over budget, and the second option did not represent value for money in comparison to the first option.

Question 38

What was the difference in cost between masonry and timber construction?

Answer 38

The timber construction was more expensive than the traditional masonry. The masonry was priced at around £40k for the masonry walls, whilst the timber framing and finish was priced at around £60k.

Question 39

What foundations were proposed for the frame to the external decked balconies?

Answer 39

Pad foundations were proposed as these would support the individual columns spanning from the decked balcony.

Question 40

On the St Wilfrid’s project, you undertook an options exercise on different foundation types. Can you describe the different foundation types? How did you build up the costs for each option?

Answer 40

The build up of a raft foundation is excavation to the required depth and then compacted, with a layer of hardcore. Earthwork is then set in place, with reinforcement bar cast within. The concrete is then poured and left to harden. The process for a piled foundation is excavation, reinforcement, cast the concrete, cut off the top, formwork for the pile cap, reinforcement and cast.

Question 41

How did you present the results of the foundation analysis on Llanbedrog and how did these compare to the clients’ objectives?

Answer 41

They were included as part of a comparative cost plan, where the differing design options and costs were presented, allowing the client to make an informed decision.