Construction Technology & Environmental Services (Level 3)

Question 1

How does planning permission impact on design?

Answer 1

• Compliance with local laws/ regulations
• Modifications to suit planning authority and public
• Constraints on land use and access

Question 2

What other legislation impacts on construction?

Answer 2

CDM Regulations 2015
Health and Safety at Work Act 1974
Building Act 1984 – inclusive of the Building Regulations as and SI.

Question 2

How does the age of the building affect construction methods?

Answer 2

Materials availability and quality
Building codes and regs
Structural design and techniques

Question 3

Can you give me examples of 2 alternative air condition systems?

Answer 3

Ground source heat pumps – uses heat from the ground in cold and warm temperatures to heat/ cool the property.
Air source heat pumps - extract heat from the outdoor air and transfer it into buildings to provide heating and hot water

Question 3

What do you understand by the term bus bar? Where would you expect to see such an item?

Answer 3

A busbar is installed within a power distribution board and is designed to connect circuit devices to isolation devices.

Question 4

What are the RIBA stages?

Answer 4

0 – Strategic Definition
1 – Preparation and Brief
2 – Concept Design
3 – Spatial Coordination
4 – Technical Design
5 – Manufacturing and Construction
6 – Handover
7 – Use

Question 5

What are the advantages of a steel framed building over a concrete frame?

Answer 5

Speed of construction
Higher weight to strength ratio
Sustainable

Question 6

Can you give me some examples of alternative drainage systems?

Answer 6

SuDS - manage surface water run off in a sustainable manner slowing rate of flow and reducing flood risk

Green roofs - a roof with vegetation and media which absorbs water.

Infiltration systems - involve directing stormwater runoff to infiltration trenches, chambers, or soakaways where it can infiltrate into the ground. Infiltration systems help reduce surface runoff, recharge groundwater, and prevent flooding

Question 7

Explain 3 different piling techniques.

Answer 7

CFA – Once the hole has been bored, concrete is pumped in, then a steel reinforcement cage is inserted.

Secant – A secant pile wall consists of overlapping (secant) piles to form structural or cutoff walls and achieve the required water tightness

Sheet - narrow sheets of material, usually designed with an angular profile and with interlocking edges

Question 8

How did you analyse the difference between the road construction and truck paving to ensure a like for like comparison?

Answer 8

Both exercises were to be delivered by the direct delivery team we had on site. The estimate consisted of labour, plant and materials for each option. The meterage for the standard road construction and truck paving was the same. I obtained quotes for the rates of each material type. I sat with the site team and discussed durations, gang sizes and applicable plant and applied it to each of their programmes.

Question 8

Did you consider how both solutions of the road construction compared on a whole life cost comparison? If so, how did you undertake the comparison?

Answer 8

Asphalt initial cost less than truckpave
Asphalt requires less maintenance and attention and repairs to specialist materials

Resurfacing risk of asphalt is minimal given its use (2 tankers per week).

Question 9

Were there any other design solutions that you explored for the roadworks?

Answer 9

A concrete road, however initial costs were too high. Even given its durability. Plus the client didn’t want this option due to its aestheics

Question 9

Can you provide another project example of you undertaking work in relation to this competency? Wigan

Answer 9

Yes, on the Wigan project we considered using a trench box method to construct a manhole, however, given the severe ground conditions this was not viable. A sheets and frame method was suggested which provides better support in poor ground conditions.

Question 9

How did the concrete and GRP designs compare from a whole life cost perspective?

Answer 9

The construction costs for both options was significantly different for various reasons, as explained in the write up.

Due to the tanks being in the ground, there aren’t any operating or maintenance costs associated.

However, the concrete pipes had a shorter life cycle and therefore would need to be replaced earlier.

Question 10

What was the effect on the programme of changing to GRP?

Answer 10

In total a saving of circa 10 weeks against the programme. This was due to:

o A saving on the manifold and pipework installation due to a lighter material, ease of handling and jointing methods.

o A saving on the backfilling due to not having to backfill around FRC works

Question 10

Did the client have any reservations about the change? If so, how did you address these?

Answer 10

The client had two reservations:

1. The initial material price was substantially more than the concrete option.
2. The duration it may take to push the change through the relevant approvals.

Point 1 was addressed by displaying the cost exercise I carried out demonstrating the saving the GRP option produced, despite the material costs being more expensive.

Point 2 was addressed by demonstrating the potential time saving on programme if we were to proceed with the GRP option. With the approval process usually being 2 weeks, this was still quicker than the concrete solution.

Question 10

What was the internal challenge to undertake value engineering?

Answer 10

The project, let on an NEC Option A, was experiencing significant losses on several subcontract packages due to insufficient allowances at tender. The project team were tasked with identifying possible value engineering solutions to recover any losses.

Question 11

Who was responsible for the design of the pipework package?

Answer 11

We produce an outline design for the subcontractor to price and progress with. They then complete the detailed design which is to be approved by the contractor.

Question 12

How much saving, in cost and time, did the change realise on Williamsgate?

Answer 12

The work was not on the critical path, however it saved a week of construction and circa £40k.

Question 13

How did you, not an Engineer, satisfy yourself that your simpler duct run solution would work/meet the specification?

Answer 13

I noticed that around the flocculation tank there were a considerable amount of drawpits and chambers. I queried the specifications requirements regarding for when duct runs have to enter a chamber. Once I knew what that the spec deemed required, I calculated that the ducts running into current drawpits could in fact extend into a chamber further downstream. I checked this with our civil designer who confirmed that the solution was viable.

Question 14

Describe different types of foundations.

Answer 14

Strip footing:

Continuous strip of concrete under load-bearing walls, distributing building loads evenly to the soil.

Pad footing:

Isolated concrete blocks supporting individual columns or point loads, transferring loads directly to the soil.

Raft foundation:

Large concrete slab extending over the entire building footprint, spreading loads evenly to the soil to minimize settlement.

Question 15

What is the make up of a road?

Answer 15

Subgrade - Compacted earth
Capping layer - 6F5 (where subgrade isn’t viable)
Subbase - Type 1
Kerbs and drainage
Trimming
Tac coat - Stick layers to asphalt
Asphalt

Question 16

How do you construct a manhole?

Answer 16

Excavation: Dig a hole to the required depth and size.
Base: Pour a concrete base for stability.
Manhole Rings: Install pre-cast concrete rings or bricks to form the manhole shaft.
Benchings: Create sloped benchings to guide water flow.
Cover and Frame: Secure a manhole cover and frame at ground level.

Question 17

Name some types of levels in construction.

Answer 17

Invert level - lowest point on the inside of a pipe, drain, or sewer.
Soffit level - highest point on the interior surface of a pipe or duct.
Ground level - The prepared ground level on which the foundation or slab will be laid
Formation level - The existing or finished surface level of the ground around a construction site

Question 18

Outline some modern methods of construction.

Answer 18

Modular Construction: Prefabricated building modules assembled on-site

Precast concete panels for easier installation on site and less waste produced on.

Timber frames - renewable materials and great design flexibility

Question 19

Talk me through the different elements of a steel frame construction.

Answer 19

1. Foundations: Concrete bases that support the steel columns, ensuring stability and load distribution.
2. Steel Columns: Vertical members that transfer loads from the structure to the foundations.
3. Beams: Horizontal members that support floors and roofs, connecting to columns and other beams.
4. Bracing: Diagonal or X-shaped members that provide lateral stability, resisting wind and seismic forces.
5. Floor Systems: Composite slabs or decking that rest on beams, providing the floor surfaces.
6. Connections: Bolts, welds, or rivets that join steel components together, ensuring structural integrity.
7. Cladding: External covering materials (e.g., panels, glass) that protect and insulate the structure.
8. Roof System: Steel trusses or rafters supporting the roof, completed with decking and waterproofing layers.

Question 20

What are the advantages of a GRP pipe over Concrete?

Answer 20

Lightweight
Corrosive resistant and better longevity
Better hydraulic performance
More sustainable construction process

Question 21

How would you go about measuring a pipework package based off a drawing?

Answer 21

No. of Pipes
Diameter / Spec
Level of excavation – Invert Level & Cover Level of manholes

Question 22

What would you have to consider when pricing a CFA piling type?

Answer 22

Piling rig, mat, excavation, disposal, rebar, concrete