2016 Higher Level Sample Solutions

Q.1.

(a)

(b)

Rainwater ingress at the roof-wall junction is prevented by the lead flashing (red). The flashing runs from under the external plaster and is dressed over the waterproofing layer (green).

Q.2.

(a)

Safety training:

All construction workers are required by law to have completed the SOLAS Safe Pass Health and Safety Awareness Training Programme. This programme gives construction  workers a basic knowledge of health and safety so they are better able to deal with the hazards and risks they will encounter on a construction site.

‘Safe Pass’ is a one day training course comprising FIVE modules:

• Site Safety and the Construction Worker
• Introduction to Risk Assessment
• Implementing Risk Assessment
• General Site Safety
• Personal Safety.

Collective responsibility:

Collective responsibility occurs when a positive safety culture has been created on the construction site. It is present when:

• everyone on site looks out for their own safety and the safety of others,
• when all workers are vigilant and safety conscious, good safety practices are followed
• working in a safety aware way becomes the norm… 'the way we do things around here',
• responsibility flows through the safety officer and safety committee and is kept in the group consciousness by regular review and update of the
  health and safety statement.

(b)

Using a ladder - level of risk:

• a risk assessment should be carried out for every task conducted on site,
• the construction worker should be aware of the hazards associated with the use of ladders,
• the construction worker should take the necessary risk control measures,
• the ladders should only be used when the risk control measures are in place,
• the ladder should be properly secured before use.

Using a ladder - duration of task:

• ladders are for short term use only,
• ladders should only be used for one-off tasks that would not necessitate the erection of a scaffold or the use of a telescopic lift,
• a ladder should only be used for a few minutes at a time,
• any task that cannot be completed in this time frame should be done with a telescopic lift.

(c)

Placing a ladder to access a scaffold platform on a construction site:

• the ladder should be secured at both ends,
• the stiles of the ladder should extend one metre above the working platform,
• the ladder should be fixed at a slope of 1:4.

Q.3.

(a)

*the simplest solution here is to rotate the floorpan through 180 degrees*

Modifying the external envelope:

• large windows have been placed on the south facade to provide natural light and heat to the main living space,
• a glazed door has been installed in the south facade,
• the main entrance door has been moved to the north facade.

Revising the internal layout:

• the main living space (kitchen/ dining/ living room) has been place to the south and west side of the floor  plan,
• the internal walls separating the living spaces have been removed,
• the bedrooms are now at the eastern end of the home,
• the bathroom and hallway (least used spaces) are now to the north side of the floor plan.

(b)

Modifying the external envelope - reasons for design choices:

• the large windows on the south facade to provide natural light and heat to the main living space
• the main living sauce is the most used space in the home - it now has four large windows (two south and two east) - this will ensure that this space has the benefit of solar gain in the afternoons and evenings,
• the south facing door is glazed to allow solar gain and to provide access to the outdoor space (e.g. patio).

Revising the internal layout - reasons for design choices:

• the main living space (kitchen/ dining/ living room) has been place to the south and west side of the floor  plan - this will ensure the home owners enjoy natural light and warmth throughout the day,
• the bedrooms are now at the eastern end of the home where they will have the morning sun and be darker in the summer evenings,
• the internal walls separating the living spaces have been removed to allow the sunlight to penetrate deeply into the home throughout the day,
• the bathroom and hallway are to the north because they do get as much use as the main living spaces.

4.

(a)

Reasons why site A may be considered suitable for a new house, include:

• the site is close to existing houses so that services such as water, electricity, phone and broadband are likely to be readily available and cost effective,
• there is sufficient space for on-site for a waste-water treatment system,
• the site has good access from the adjoining roads - the roads are mainly straight and should allow clear sight-lines to ensure safe access to the site.

(b)

Location and orientation of house; access entrance:

Justification:

• The house is rectangular in plan; oriented with the long axis running west-east. This ensures the main facade is south facing to optimise solar gain. The house is located in the northern half of the site; this minimises the visual impact of the house when the site is viewed from the main road. 
• The main entrance is at the north-east corner of the site bringing the driveway along the existing northern boundary. This ensures the southern area of the site is natural (grass & other planting) and the garden can run right up to house. The use of artificial paved surfaces (e.g. tarmacadam) is reduced. Both of these design decisions minimise the visual impact of the site on the landscape. This access point works because there are clear sight-lines along the road in both directions. Also, this is a smaller quieter road with much less traffic than the road to the south of the site.

Advantages:

• living in the countryside is a different way of life, compared to urban and suburban living, with a long tradition in Ireland. Many people prefer this way of life and are from multi-generational families who have always lived in these areas. Building new home sin the countryside continues this tradition and allows local people to live amongst their neighbours and extended family.
• many rural dwellers work in agriculture providing the food that everyone eats - it is important for the future health of society and for the health of the planet that everyone eats locally sourced food. Building new homes in the countryside provides housing for these workers and their families and allows small old energy inefficient houses to be replaced with new passive house standard homes that meet the needs of modern family life.

Disadvantages:

• building one-off houses in the countryside for people who do not work there creates a lifestyle that is dependent on the use of cars. This has negative impact on the environment (e.g. air pollution).
• allowing a proliferation of one-off houses in the countryside has a negative impact on the visual amenity for everyone.
• every one-off house built in the countryside has to have a waste-water treatment system installed. Over time poor maintenance of these systems can lead to pollution of the groundwater and local water courses.

5.

(a)

(b)

(c)

6.

(a)

A large area of glazing to the corner:

• the glazed corner is oriented to the south-west; it will benefit from a high level of solar gain, providing heat and natural light,
• this will reduce the need for fossil fuel (e.g.oil, gas, coal, peat) based heating,
• this will reduce CO2 emissions and heating costs.

Open plan layout with central heat source:

• the solid fuel (e.g. wood) stove located in a central location provides heat to the entire ground floor of the home,
• the masonry fire surround and chimney acts as a thermal store holding heat energy and releasing it as the temperature drops when the stove is no longer in use.

Construction materials:

• the walls are insulated timber frame with some cedar cladding,
• timber is a sustainable construction material that can be sourced locally,
• a sustainable insulant (e.g. wood fibre or sheep’s wool) can be used in this wall to further reduce the environmental impact of the construction materials while still providing a very high level of thermal performance,
• these materials have a low embodied energy and are from sustainable sources.

(b)

(c)

Two advantages of generating energy on-site, include:

• reduced reliance of energy from the national grid - most of which is generated by burning fossil fuels which produces greenhouse gases and is harmful to the environment,
• reduced energy bills - generating energy on-site reduces the consumption of energy from the national grid which has to be paid for by the home owner.

7.

(a)

(b)

For a sloped roof (pitch greater than 10 degrees) the following rules apply:

• chimney less 600mm from ridge = chimney should extend a minimum of 600mm above the ridge
• chimney greater than 600mm from = height from highest point of contact with roof to top of chimney should be a minimum of 1m

8.

(a)

Two advantages include:

• it is more sustainable to find a new use for an old building than it is to demolish the old building and replace it with a new one,
• it will provide a nice quiet space in the garden in which to work.

Two disadvantages include:

• the building might be in very poor condition making refurbishment slow and expensive,
• the geometry of the building (internal dimensions; especially ceiling height) may not make it suitable for refurbishment.

(b)

Justification:

Walls:

• external insulation will upgrade the thermal performance of the walls without reducing the internal dimensions of the already small space,
• a breathable (e.g. woodfibre) insulant will ensure that the wall retains its ability to regulate moisture and prevent interstitial dampness.\

Floor:

• the original floor is removed; the original stone floor finish can be reinstalled if desired,
• a well insulated concrete floor is installed (including a damp proof membrane/ radon barrier) to ensure good thermal performance of the floor.

9.

(a)

Ring circuit:

• a ring circuit is used typically for sockets in adjacent rooms in a home,
• a separate ring circuit is required for every 100m2 of floor area,
• the number of sockets in a ring circuit is unlimited,
• a two socket spur may be connected to half of the main sockets,
• a 2.5 mm2 twin & earth double insulated cable is used,
• the ring circuit is protected by a mini-circuit breaker with a rating of 32A,
• the length of copper cable required is kept to a minimum.

Radial circuit:

• a radial circuit is used for sockets or lighting,
• a maximum of ten sockets can be installed on a radial circuit,
• a 2.5mm2 twin & earth double-insulated cable is used for sockets,
• a 1.5mm2 twin & earth double-insulated cable is used for lighting,
• a radial circuit is typically protected by a 20A mini-circuit breaker.

(b)

Safety features:

• a fuse or miniature circuit breaker protects the circuit - a miniature circuit breaker (MCB) is an automatic switch that instantaneously interrupts the flow of current in the event of an overload (too much current) or short circuit (accidental connection between the live conductor and the neutral conductor or between the neutral conductor and the earth conductor),
• the circuit is earthed - earthing is the connection of the exposed conductive parts of an electrical installation to the main protective earthing terminal of the installation. The idea is that should the body of an appliance become live, the current will have a safe path and a person touching the appliance will not be shocked.

   

(c)

Two features to ensure economical use of energy, include:

• using LED lamps instead of tungsten or fluorescent lamps - LED lamps have significantly higher luminous efficacy (light produced per watt of electricity) and up to ten times longer life span,
• using automatic motion sensors to control outdoor lighting - sensors ensure the light is only on when someone is present and significantly reduce energy consumption.

10.

(a)

Foundations:

Insulated foundation:

• an insulated foundation is necessary to avoid thermal bridging down through the loadbearing walls,
• insulated foundations prevent this by ‘wrapping’ the substructure in insulation,
• high density loadbearing polystyrene (EPS 300) is used,
• a number of proprietary systems are available in Ireland, (e.g. Kingspan Aeroground)
• each of these systems ensure that there is no thermal bridging between the ground and the substructure.

Insulated ground floor:

Insulated floor:

• a highly insulated thermal bridge free floor is essential to prevent heat loss,
• 300mm of high density expanded polystyrene (thermal conductivity0.031W/m2K) or equivalent.

(b)

Overheating can occur because:

• there is inadequate solar shading provided - this happens when the design relies on human intervention (e.g. a person raising and lowering a blind to regulate solar gain) instead of having features built in to design to do this (e.g. roof overhang),
• there is inadequate ventilation - if the mechanical ventilation system is not operating correctly the internal temperature will continue to rise. The system should be in summer bypass mode providing a constant supply of cool fresh air to the habitable rooms of the home throughout the day.

(c)

Advantages of passive house construction: 

• low energy consumption - a typical passive house uses 75-90% less energy than a similar house built to building regulations standards,
• comfort - passive house construction provides a consistent level of comfort (a constant comfortable temperature of 20°C is maintained all year round),
• economical - a typical passive house significantly cheaper to run than a similar house built to building regulations standards
• reduced environmental impact - lower energy consumption means that passive houses have a much smaller carbon footprint than houses built to building regulations standards - reduced CO2 emissions

Disadvantages of passive house construction: 

• workmanship - a very high level of workmanship is required on site - every member of the construction team must understand what is required to achieve passive house standard and ensure that their work is of the highest possible standard
• training - tradespeople and designers need to be trained to ensure they are competent to achieve passive house standards