Construction Tech MO

Question 1

Types of foundations?

Answer 1

Piled, Pad and Strip

Question 2

What are Piles?

Answer 2

Long columns driven or bored into the ground to transfer loads to stronger, deeper ground.

Question 3

How do you price piles?

Answer 3

Number of piles (count)

Length per pile (linear metres)

Diameter (mm or m)

Plus ancillary items, e.g.:

Cutting down pile heads

Reinforcement (mass per pile or per m)

Pile caps / beams

Testing (static load, integrity, dynamic)

Temporary casing or bentonite support (for bored piles)

Question 4

When do you use piles?

Answer 4

Weak/poor soil/bad ground conditions, heavy loads & basements

Question 5

What are underpins?

Answer 5

Underpins are blocks or sections of a new foundation built beneath or beside an existing one to strengthen or stabilize it, transferring the load to stronger ground below.

Question 6

Types of piles?

Answer 6

Driven, bored, sheet, mini

Question 7

Piles - Advantages & Disadvantages?

Answer 7

Pro’s - heavy loads, can be used in poor soil.
Con’s - Expensive, specialist, sound/movement for neighbours

Question 8

What are bored piles?

Answer 8

Drilled using an auger/rotary rig, used for basements, deep foundations. They cause low vibration & noise. But are slower, more expensive and spoil management is required.

Question 9

What are driven piles?

Answer 9

Hammered to vibrated into the ground. Good for new builds (open access). Fast installation & quality control. But cause a lot of noise & vibration.

Question 10

What are sheet piles?

Answer 10

Sheet piles are steel sections driven into the ground to form a wall.

Pros: Quick to install/remove, minimal excavation, reusable.

Cons: Noisy, vibrations, limited in hard ground, may need support, can corrode.

Question 11

What are mini piles?

Answer 11

Drilled/grouted with a rig, used for basements and where you are also underpinning and have restricted access. Minimal vibration but more piles required and is slow.

Question 12

What are CFA piles?

Answer 12

CFA Continuous Flight Auger piles

Bored, cast-in-place concrete piles formed using a continuous auger to drill into the ground and then pumping concrete through the auger stem as it is withdrawn — creating the pile without ever leaving the bore open.

Question 13

How do you price underpins?

Answer 13

Underpins are priced by volume or per pin, based on type, depth, and access. Rates include hand excavation, concrete, reinforcement, and temporary works.

Question 14

What are pad foundations?

Answer 14

Pad foundations are individual blocks of concrete that support single point loads e.g. columns

Question 15

What are strip foundations?

Answer 15

Strip foundations are continuous strips of concrete that run under load bearing walls

Question 16

When do you use pad foundations?

Answer 16

Ground had good bearing capacity, with steel and concrete frames. Pros cheap, quick, easy to inspect. Cons not suitable for weak ground conditions.

Question 17

When do you use strip foundations?

Answer 17

Masonry/framed buildings, moderate bearing strength. Pros economical & low risk, cons not suitable for weak ground conditions and only used for low rise buildings.

Question 18

What is raft foundations & when do you use them?

Answer 18

A raft foundation (also called a mat foundation) is a large, thick reinforced concrete slab that spreads the load of a building over a wide area, often the entire footprint of the structure. Weak or variable ground, large building footprint, Light to medium loads, low rise.

Question 19

Steel vs Concrete frame?

Answer 19

Steel Frame: steel column & beams support floors & roof. Loads carried through the frame, walls are non loadbearing. Pros fast, high strength to weight ratio, recyclable. Cons fireproofing, potential corrosion, expensive.

Concrete Frame: Frame made from concrete columns, beams & slab. Loads transferred through the RC frame to the foundations. Pros - fire & accoustic performance, flexible shapes, durable, low maintenance. Cons slow & heavy.

Question 20

Life Cycle Costing vs Whole Life Cycle Costing?

Answer 20

Life Cycle Costing: includes capital, maintenance, operational, replacement and disposal costs for a building.

Whole Life Cycle Costs: The total cost of ownership over the life of an asset, including acquisition, operation, maintenance, and disposal costs, plus the costs (or benefits) of externalities.

Question 21

What are the approved documents?

Answer 21

Approved Documents are official government guidance that explain how to meet the functional requirements of the Building Regulations in England.

Question 22

Examples of approved documents?

Answer 22

A - Structure - stability, loading, etc.
B - Fire Safety - Means of escape, fire spread, access for fire services
C - Site Preparation & Resistances to Contaminants/moisture

L - Conservation of fuel & power - energy efficiency, insulation, U-values
M - Access to & use of buildings - disabled access, step free entry

Question 23

Are approved documents mandatory?

Answer 23

They are not mandatory — but following them provides a “deemed-to-satisfy” route to compliance.
If you follow what’s in the Approved Documents, Building Control will normally accept that your design meets the Regulations.

Question 24

How do you construct a basement?

Answer 24

Excavation, piling (CFA piles), underpinning (neighbouring property), basement slab, external walls, waterproofing (waterproof concrete & cavity drain).

Question 25

How do you price basement construction?

Answer 25

Enabling & temporary works (hoarding, scaffolding, propping, facade retention) Piling or underpinning (retaining structure) Bulk excavation & disposal Waterproofing system (Type A, B or C) Reinforced concrete works (base slab, walls, columns, capping beams) Drainage & sump pumps Fit-out (M&E, finishes, stairs, lighting) Element Unit Notes Excavation to reduced level m³ Include temporary supports, over-dig, working space Piles or underpins m / m³ By diameter, depth, or number of pins Concrete to base slab / walls m³ Include reinforcement and formwork Waterproof membrane / cavity drain m² By system type Drainage and sumps m / no. With pumps and chambers Backfill m³ Type and compaction Waterproof screed or insulation m² Floor buildup Internal fit-out item / m² Finishes, M&E, joinery, access

Question 26

Cost per m2 of a recent basement construction you priced?

Answer 26

£1,900/m2

Question 27

How do you price temporary works?

Answer 27

Scaffolding Facade retention frame - columns, walers, props, bolts & fittings Propping Shoring Design, Installation & Removal

Question 28

What façade type was Rutland gate?

Answer 28

Render finish over a brick & block wall

Question 29

Types of façade?

Answer 29

Masonry (brick, stone, blockwork) Curtain Wall (non load bearing external wall fixed to the building structure) Precast Concrete Façade (Large concrete panels cast off-site and lifted into place as part of a structural or non-structural envelope.) Timber Façade / Timber Cladding Glazing

Question 30

How do you retain a façade?

Answer 30

To retain a building's facade, it is either temporarily supported with external or internal steelwork while the interior is rebuilt, or the facade is carefully dismantled, stored, and then rebuilt.

Question 31

How did you price façade retention?

Answer 31

Steel retention frame - external steel retention frame with walers and needles, raking props, temporary foundations for the frame Protection of retained structure Demolition New structure built, movement joints included

Question 32

What temporary works did you do?

Answer 32

The facade was temporarily propped by a steel frame.

Question 33

Examples of the benefits of the two options on Rutland Gate (Façade retention or New Build)?

Answer 33

New Build: Shorter programme, lower cost, easier construction Façade Retention: Already had planning approval

Question 34

Which option was more cost effective on Rutland Gate (Façade retention or New Build)?

Answer 34

New Build

Question 35

How do you price services?

Answer 35

per m2 or speak to an M&E surveyor

Question 36

What is delta membrane?

Answer 36

Cavity Drain Waterproofing system; essentially collects the water and directs it to a sump pump where it is then removed to an external drainage point

Question 37

What did you advise on Rutland gate?

Answer 37

That the more cost and programme efficient option was new build.

Question 38

How did you under take the cost analysis of Façade retention vs New Build?

Answer 38

I compared façade retention and new build by preparing elemental cost plans I analysed key differences in demolition, temporary works, and preliminaries. Compared cost & programme factors to help the client make a decision.

Question 39

What prelims cost did you consider when comparing the Rutland Gate options?

Answer 39

Time related prelims mainly, as the programme was increasing by approx. 25 weeks

Question 40

What was the issue in terms of the condenser units on Victoria Road?

Answer 40

Where to put them, between the roof and the basement

Question 41

What did you advise on Victoria Road in terms of the condenser units?

Answer 41

That the roof was more cost effective

Question 42

How did you cost the two options on Victoria Road?

Answer 42

Roof Option: Removal of existing roof, modification of existing roof structure to allow new flat roof area, plinth, additional works (pipework, fixing etc.) Basement: Reinforced basement underpins Reinforced concrete capping beam; 350mm x 600mm 150mm thick well compacted hardcore Blinding; 50mm thick 100mm FOAMGLAS T4+ slab insulation Reinforced screed; 70mm thick Kingspan Thermalon TF70 insulation; 70mm Isocrete K screed; 70mm Excavate for new basement Compact bottom and sides of excavation Reinforced concrete liner wall Cetco Voltex waterproof membrane Cavity drainage membrane to walls Cavity drainage membrane to floor Secondary System - Waterproof Concrete Concrete Slab; 275mm, Formwork, Reinforcement and Insulation Louvred screen and door to plant room

Question 43

What is PI?

Answer 43

Professional indemnity (PI) insurance is liability insurance that covers professionals and companies against claims of negligence, errors, or omissions in their advice or services.

Question 44

Name a project where you priced piling?

Answer 44

Victorria Road

Question 45

What piling would you use for a retaining wall?

Answer 45

Steel sheet piling or CFA piling

Question 46

You estimated costs for beams on Rutland Gate? What type of beams and how?

Answer 46

On Rutland Gate, I estimated costs for structural steel beams forming part of the frame. “I estimated the beams using tonnage-based rates from benchmark data and subcontractor input. I included fabrication, erection, connection detailing, and temporary works.

Question 47

What was the difference in total cost between the façade retention option and new build option?

Answer 47

£1.5mil (£140k more strip out, 25 weeks more programme 1mil)

Question 48

What is run off cover?

Answer 48

Run-off cover is PI insurance that protects a firm after it stops trading, covering any claims made later for work done before it closed.

Question 49

What is CHP?

Answer 49

CHP – Combined Heat and Power Generates electricity and heat at the same time from one fuel source (usually gas). The electricity powers the building, and the waste heat is reused for heating or hot water. Improves efficiency and reduces energy waste, but relies on fossil fuels unless adapted for renewables.

Question 50

What is ASHP?

Answer 50

Extracts heat from the outside air (even when cold) and uses it to heat the building. Works like a reverse fridge. Cheaper and easier to install than GSHP, but less efficient in very cold weather.

Question 51

What is GSHP?

Answer 51

GSHP – Ground Source Heat Pump Uses heat from the ground to warm the building. Pipes buried in the ground absorb natural heat; a pump transfers it into the heating system. Efficient and sustainable — low running costs but high installation cost.

Question 52

GSHP or ASHP?

Answer 52

GSHPs are more efficient year-round due to consistent ground temperatures, but have high upfront costs for installation. ASHPs are cheaper and easier to install, but are less efficient in cold weather, leading to higher running costs during winter.

Question 53

Name some M&E systems?

Answer 53

Cooling / Air Conditioning; FCU, VRF/VRV Fire Protection: Sprinklers, dry risers, wet risers, suppression systems Power distribution: The generation, transmission, and distribution of electricity throughout a building. Lighting: Both interior and exterior lighting systems. Security and safety: Fire detection, alarm systems, and access control.

Question 54

What are condenser units?

Answer 54

A condenser unit is the outdoor component of an air conditioning or heat pump system that releases heat to the outside air to cool the indoor space.

Question 55

How do you price frames?

Answer 55

Calculating the total tonnage of steel, applying rates for material, fabrication, and erection, and adjusting for complexity

Question 56

What is BREEAM?

Answer 56

Building Research Establishment Environmental Assessment Method

Question 57

BREEAM Scoring?

Answer 57

Unclassified: Less than 30% score. Pass: 30% or above. Good: 45% or above. Very Good: 55% or above. Excellent: 70% or above. Outstanding: 85% or above.

Question 58

What is BSR?

Answer 58

The Building Safety Regulator (BSR), part of the HSE, was created by the Building Safety Act 2022 to improve building safety. It oversees higher-risk buildings, raises safety standards, and ensures competence across the design, construction, and building control sectors.

Question 59

What is HRB?

Answer 59

HRB stands for Higher-Risk Building in the context of the Building Safety Act in the UK. It refers to a building that is at least 18 meters high or has at least seven storeys and contains at least two residential units.

Question 60

What is the BSA?

Answer 60

The Building Safety Act 2022 improves building safety by introducing stricter rules for higher-risk buildings (over 18 m or 7+ storeys). It establishes the Building Safety Regulator (BSR) and defines clear duty holder responsibilities for design, construction, and building management.

Question 61

What are the gateways in BSR/BSA?

Answer 61

**Gateway 1 – Planning Stage** Fire statement required with planning application. Local authority must consult the HSE. **Gateway 2 – Pre-Construction** “Stop/go” point before work starts. Building Safety Regulator (BSR) must approve detailed design for Building Regs compliance. **Gateway 3 – Completion** Final “stop/go” before occupation. BSR confirms as-built works meet approved plans and Building Regs. Completion certificate issued → only then can building be occupied.

Question 62

When preparing early estimates, how do you decide what foundation types to cost for?

Answer 62

Depending on ground conditions, loads, building height.

Question 63

What are some different types of Waterproofing?

Answer 63

Type A: Bentonite Slurry / Tanking Type B: Waterproof Concrete Type C: Cavity Drain Membrane

Question 64

What is Bentonite Slurry / Tanking?

Answer 64

A barrier system where bentonite clay or cementitious slurry is applied to the structure; it swells on contact with water to form a waterproof seal that stops water entering the basement.

Question 65

What is waterproof concrete?

Answer 65

The basement is built using watertight reinforced concrete, with cracks kept very small and additives mixed in to help resist water, so the structure itself stops water getting in.

Question 66

What is Cavity drain membrane?

Answer 66

A studded plastic membrane is fixed to the walls and floor, allowing water to enter the cavity and be controlled and drained to a sump and pump system, rather than trying to stop it. The sump pump then pumps it up and out into a drainage system

Question 67

Different classifications of basements?

Answer 67

Basements are classified by the level of water resistance required: Grade 1 – Basic utility Some water ingress acceptable (e.g. car parks, plant rooms). Grade 2 – Better utility No water penetration, but dampness tolerated (e.g. storage areas, workshops). Grade 3 – Habitable Completely dry environment required (e.g. bedrooms, living spaces, offices).

Question 68

What is the structure of Victoria Road?

Answer 68

A piled and underpinned basement, supporting a steel frame superstructure, with solid masonry external walls finished in rendered or stuccoed brickwork.

Question 69

When is a steel frame more suitable?

Answer 69

When speed of construction is important, Reduced structural weight is needed (basements, or poor ground)

Question 70

What is formwork and what formworks are there for concrete buildings?

Answer 70

**The temporary mould used to shape and support concrete until it gains sufficient strength** **Slipform** – continuous pour system used for cores and high-rise structures **Jumpform** / climbing formwork – used for vertical elements like lift cores **Tunnel** formwork – casts walls and slabs in one operation (housing/high-rise)

Question 71

What year was Rutland Gate built?

Answer 71

1985-1987

Question 72

What is Curtain walling?

Answer 72

Curtain walling is a non-loadbearing external façade system, typically made of glass, aluminium or steel, that is hung from the structural frame of a building

Question 73

When is curtain walling used?

Answer 73

Curtain walling is used on buildings where a lightweight, glazed façade is required without carrying structural loads.

Question 74

What are some key risks in basement builds?

Answer 74

"Ground Obstructions Contamination Archaeological"

Question 75

How do you waterproof concrete?

Answer 75

Add an additive into it

Question 76

What is a bitumen membrane?

Answer 76

A bitumen membrane is a waterproofing material made from bitumen (a petroleum-based product), used to prevent water ingress in areas such as roofs, basements and foundations. It is typically applied as rolls or liquid coatings

Question 77

Cost factors that effect steel costs?

Answer 77

Transport costs, tarrifs & ukraine war

Question 78

Why use bored over driven piles?

Answer 78

Vibration and noise must be minimised, such as near existing buildings or party walls Ground conditions are variable, allowing pile depth and diameter to be adjusted during drilling

Question 79

What is a construction risk?

Answer 79

A construction risk is any unforeseen event that may occur during a construction project

Question 80

What is the structure of 50 Victoria road?

Answer 80

Piled and underpinned basement, steel frame superstructure, and traditional solid masonry external walls.

Question 81

Why use steel for high-rise buildings?

Answer 81

For its strength, speed of construction, reduced weight and flexibility

Question 82

Risks of cavity drain membrane?

Answer 82

Maintenance requirements and man hole connections etc.

Question 83

Tell me about waterproofing systems?

Answer 83

Waterproofing system requires two forms, which in this case where the secant piles to to its density and the delta membrane, backed up by a sump pump.