Construction Tech

Question 1

What are the advantages of a steel frame?

Answer 1

1) Beams span over long distances
2) High strength to weight ratio
3) Recyclable
4) Quick to erect on site

Question 2

What are the disadvantages of steel?

Answer 2

1) The price of steel can be volatile.
2) Fire protection may be required.
3) Steel frames have lesser acoustic and thermal properties than concrete frames.

Question 3

What can affect the cost of a steel frame?

Answer 3

1) Number of connections to beams
2) Making the steel fire resistant, with intumescent or boarding it.
3) Improving the acoustic qualities

Question 4

How can you improve the acoustic qualities of a steel frame?

Answer 4

1) Whilst it might not improve the frame itself, I am aware of being able to install acoustic suspended ceilings to increase the acoustic performance of a building.
2) Insulation in ceilings and walls.

Question 5

What are the advantages of a concrete frame?

Answer 5

1) The price of concrete is typically more stable than steel.
2) Fire protection is inherent in the structure
3) Provides good sound and heat insulation.

Question 6

What are the disadvantages of a concrete frame?

Answer 6

1) Takes longer to install on site than steel & timber
2) For concrete’s maximum strength, can take up to 28 days for concrete to cure.
3) Concrete does not span as well as steel.

Question 7

On the project in Chigwell, why was a timber frame not identified as an option?

Answer 7

I did pose this question to my Client and asked if they would consider a timber frame, but this was quickly shut down. I’m not sure if the Client had issues with timber in the past, but the Client was not willing to entertain timber.

Question 8

What are the advantages of a timber frame?

Answer 8

1) Sustainable benefits
2) Construction on-site faster than concrete.
3) Structure is relatively lightweight

Question 9

What are the disadvantages of a timber frame?

Answer 9

1) Can be difficult to source the required sizes and quantities of timber
2) Fire protection may be required.
3) Potential for wet rot, dry rot, woodworm etc.

Question 10

How can you improve the fire resistance of a timber frame?

Answer 10

1) Fire resistance intumescent
2) Board it with fire-resistant boads.

Question 11

What are the differences in cost between a steel frame and concrete frame?

Answer 11

For a two storey, circa 20,000ft2 GIA, I would anticipate costs for a concrete frame to be around £200/m2 Q1 2025.

For a steel frame, I would anticipate costs to be around £270/m2 Q1 2025, although there would be additional costs for requirements to enhance the fire resistance and acoustic qualities of the steel frame.

Question 12

What is CAT A construction?

Answer 12

A very basic form of fit-out for a commercial building, typically only including elements necessary for occupation.

It is a blank canvas for interior and office designers, the next phase is Cat B.

Question 13

What are the main components of concrete?

Answer 13

1) Cement
2) Aggregate
3) Water

Question 14

What is reinforced concrete?

Answer 14

Concrete with reinforcements, usually steel bars, rods or mesh.

Question 15

What should be considered when selecting the type of structural frame?

Answer 15

1) Programme requirements
2) Fire protection
3) Acoustic and thermal properties
4) Market conditions and supply cost
5) Site logistics and general constraints

Question 16

What is Cat B construction?

Answer 16

CAT B fit out provides a space that is ready to move into and operate.

Question 17

Can you tell me what a Principal Designer is, and where this role is defined?

Answer 17

The principle designer is a role listed under the CDM regs. The principal designer is the designer with control of the pre-construction phase.

This role is defined under the Building Regs (Building Safety Act)

Question 18

For Chigwell house, why was a masonry construction not considered in your advice?

Answer 18

Masonry construction (brick) formed the external wall. I advised on the choice of frame.

Question 19

Can you run through some characteristics that would impact the cost of Steel/concrete frames?

Answer 19

1) Whether it is made on/off site.
2) Reinforcement to concrete
3) Number of connections for steel.

Question 20

You advised that the cables could be installed high level rather than in a trench. Is this not outside your PI? Especially since it seems that way forward would never have worked.

Answer 20

I advised on the opportunities that could result in a cost saving and brought this to the attention to the design team.

I did not advise the design team to change their design, I advised them that there would be a cost saving by installing the cables at high level rather than in the trenches, it was for the design team to assess if this was feasible.

Question 21

For the trench, why did it need to be fully opened? Why were the cables not just pulled through?

Answer 21

There was asbestos in the trench that had to be removed.

This also meant that the cables were contaminated, and had to be cleaned and double bagged once removed and couldn’t be pulled through.

Question 22

On project infrastructure, how did your knowledge of construction tech help with your assessment of labour requirements for the temp flooring?

Answer 22

I was able to break down each element of construction and allocate estimated time frames for the completion of the works to calculate the total duration of install.

Question 23

What is blue plasterboard?

Answer 23

Acoustic rated plasterboard

Question 24

Can you tell me the build-up of a stud partition

Answer 24

1) Top and base plate
2) Vertical studs
3) Insulation
4) Plasterboard
5) Pattressing if FCU’s are inside

Question 25

For your Leeds OCE, why were you doing a measure rather than another method? Is that in line with what NRM 1 says?

Answer 25

I was able to use benchmarked data to make assumptions on the different elements to give my Client more accurate cost data.

Question 26

Who defines the meaning of Cat-A and B?

Answer 26

BCO - British Council for Offices

Question 27

What type of frame would you expect for a house?

Answer 27

Timber

Question 28

What type of frame would you expect for a warehouse?

Answer 28

Steel portal frame

Question 29

What is the difference between glu-lam and CLT?

Answer 29

The main difference is how they are oriented and used for in the building. CLT: - Layers are glued together at right angles to each other - CLT is used for walls and floors Glu-Lam - Layers are glued together in the same direction, so timbers strength goes in one direction. - Glu-lam used for load-bearing, such as beams, columns etc

Question 30

Can you tell me 2 key pieces of construction tech regulation, and what they outline?

Answer 30

1) Building Regulations 2) Building Safety Act 2022

Question 31

What are the Building Regs?

Answer 31

A set of approved documents detailing the requirements for a building with regards to different key elements, such as fire safety, structure, access into the building, maintenance, ventilation etc.

Question 32

What is the Building Safety Act 2022?

Answer 32

It is a law that was introduced following the Grenfell fire to improve the safety of Buildings in the UK. One key piece of the Act was the need for Two or more staircases in buildings over 7 storeys in height or over 15m.

Question 33

What buildings does the Building Safety Act 2022 apply too?

Answer 33

All buildings that are subject to Building regulations, with particular controls for high-risk residential buildings.

Question 34

Do the Building Regulations apply to all buildings?

Answer 34

No - there are some buildings not subject to Building Regulations, such as temporary buildings (site accommodation) or extensions that are less than 30m2.

Question 35

Regarding the PSUM flooring works, how were you able agreed a reduced value with the contractor when the item is provisional and note design or defined?

Answer 35

This was agreeing the final cost of the provisional sum once the scope had been defined. I liaised with other Contractors to break down the construction sequence and allocated time to each process. I held a face to face meeting to review this with the Contractor and took notes of the meeting. I agreed the costs and reiterated the discussions held in the meeting in writing.

Question 36

On Chigwell, can you explain the advice regarding steel / concrete frame and why the client opted for concrete?

Answer 36

I advised my Client on the key differences, and why concrete would be more suited to their requirements than steel.

Question 37

What other considerations did you account for when reviewing the different frame types?

Answer 37

Steel could create a better NIA due to concretes bulky structure. I also considered the impact on foundations, as steel is lighter than concrete and could reduce volume of the concrete raft foundation. However, it would be for the design team / structural engineers to assess the impact on foundations.

Question 38

What assumptions did you make when reviewing the costs for steel vs concrete?

Answer 38

I excluded adjustments to the foundations and assumed PIR boards to achieve a 60 minute fire rating to the steel. I also assumed rates based on benchmarked data from Q1 2025.

Question 39

Did you factor in the time / prelims saving in installing steel vs concrete?

Answer 39

I adjusted the preliminaries on a week basis. I assumed concrete to take 11 weeks and steel to take 5 weeks to install, at £6k/week.