GREEN RETROFIT• Green retrofit, home energy retrofit, home retrofit, Deep energy retrofit and home performance retrofit are terms with overlapping meaning for retrofits that ensure the maintenance and preservation of buildings and the continued operation and maintenance of energy efficiency technologies. The meaning ranges from steps home owners can do themselves to buying up distressed properties and making them certifiably green.

Steps home owners can do include the following:

Insulation, primarily roof/ceiling/attic and secondary walls and floor Retrofitting heating equipment’s in older houses, results in house-hold savings of 30 –

80% due to cut in energy-use and a reduction of CO2-outlets by 30 – 100%. Thermostats in all rooms New windows. Plugging air leaks. Tuning up heating and cooling (HVAC) systems. Switching to compact fluorescent light bulbs and/or LED light bulbs Choosing appliances with low energy consumption. In the United States, this is certified

by the Energy Star. Reducing water use by installing aerators and low-flow showerheads Switching to green power, including solar energy and renewables such as heating-

pellets and bio-gas Using low-VOC products to improve indoor air quality Planting native plants and other appropriate landscaping measures.

Green retrofits are any kind of upgrade at an existing building that is wholly or partially occupied to improve energy and environmental performance, reduce water use, and improve the comfort and quality of the space in terms of natural light, air quality, and noise—all done in a way that it is financially beneficial to the owner. Then, the building and its equipment must be maintained to sustain these improvements over time.

Green retrofits are becoming more popular than new green construction. They are a less risky investment because there is no cost to build the main components of the building. Green retrofits are also more efficient in that they use minimal to no new natural resources to construct the components of the building.

Weather Beacon at Canada Life, at 330 University Avenue, Toronto. The green upgrade from incandescent light to LED (light emitting diode) is to reduce energy consumption.

Impacts of the built environment:

What are some of the green aspects of buildings? 

Physical building components, design of the buildings, systems of operation, and

interior spaces.

What are some specific examples of green-ness?

 Proximity to transit infrastructure; building materials that have good insulation and

low emission of harmful substances; alternative energy sources; double plumbing to use

rain water or grey water; roof gardens; and interior garden walls.   

Retrofitted interior of Adamson Associates Architects Toronto Office, 401 Wellington Street East. LEED EB: O& M certified.

What is green retrofitting?

 Remodeling or upgrading partially or fully occupied building interiors and exteriors

with green elements and systems without interrupting the daily routines of the occupants.

Green retrofitting can be done piecemeal, i.e. small-size green update at a time. However,

comprehensive retrofits, though more expensive initially, are more effective over the long

term as the coordination of green elements and systems results in their increased

combined benefits.

What are the benefits of green retrofitting?

 Lower cost of operating buildings; improved quality of spaces, for example, through

natural lighting; gain in floor area (in some instances) due to the replacement of bulky

mechanical equipment and building materials with thin variety; improved corporate image

in social responsibility; tax credits and government incentives; lessened impact on

infrastructure; efficient use of natural resources; and lessened ecological impact.

Are new buildings greener than retrofitted? No. In fact, using existing buildings is more

resource-efficient than new green construction; it doesn’t use new resources for the

building components and the construction process. In addition, green retrofits are a safer

investment than new green construction as there is no cost for the construction of the main

components of buildings.

Before retrofitting            After retrofitting

First Canadian Place, 100 King Street West, Toronto, ON M5X 1A9, Retrofitted building,

LEED-EB: O&M. The marble cladding was replaced with green cladding.

What are the disadvantages/challenges of green retrofitting?The initial cost of green retrofitting or building a new green building maybe high;

there is an uncertainty factor in terms of what you might encounter inside an existing building (inside walls, roofs); there is no guarantee that building retrofits increase property value; industry professionals are not very well versed in greet retrofitting; the benefit of retrofitted buildings is in reducing operating costs once the relatively expensive retrofitting is done; developers need proof and there doesn’t seem to be a data a lot of data to support the benefits of green retrofits/construction; and potential liability issues could arise in a case of green retrofits not saving on operating costs.

POSSIBLE MATERIALS FOR GREEN RETROFITTING

INTERNAL WALL INSULATION

EcoStud is used for the thermal insulation of solid walls as part of the ThermoShell Internal Wall Insulation (IWI) System.

EXTERNAL WALL INSULATION

Jablite board is suitable for adding insulation to the external face of the external construction.

Insulation boards are adhered to the existing substrate using the adhesive, allowing each board to be leveled. Once the adhesive has dried, typically five mechanical fixings per board are installed through the insulation into the solid brickwork. The insulation is made watertight and robust with one to two layers of reinforcing mesh

embedded with two layers of base coat. The desired finish is then applied.

Sill Extension

NON-HABITABLE ROOF SPACE INSULATION

Knauf Earthwool Loft Roll 44 is an unfaced glass mineral wool roll which is lightweight, flexible, resilient and non-combustible.

The total thickness of roof insulation we recommend is 400mm, laid in 3 layers. The first layer is laid between the ceiling joists and should be the same depth as those joists. The second and third layers should be cross laid over the

top of the first layer and ceiling joists. If an external wall insulation system is being installed then the loft insulation should continue over the internal skin of the external walls and down to touch the external wall insulation. Ensure void between rafters and gable walls are filled with insulation to the same height as the main insulation to avoid heat loss. The roof space above the insulation should be adequately ventilated using felt lap vents installed within the overlaps of the existing roofing felt to allow air movement above the insulation and thereby reducing the formation of condensation on the underside of the felt.

Climaflex Pipe Insulation

Felt Lap Vent

SUSPENDED TIMBER FLOOR

Knauf Earthwool Loft Roll 44 is an unfaced glass mineral wool roll which is lightweight, flexible, resilient and non-combustible.

When an existing dwelling has a suspended timber joist ground floor, the best way to upgrade the thermal ability of the floor is to install flexible insulation between the joists. To do this the floor boards will need to be taken up, so this process is best carried out when a dwelling is

empty or one room at a time with all the furniture and floor coverings removed.

EXTERNAL DOORS

New doors should be positioned on a bed of mortar with the rear of the frame in the same location as the existing, reducing the amount of disruption required within the dwelling. Once positioned, fix through the frame into the brickwork ensuring packers are placed between the frame and the wall at the fixing locations to offer maximum support. There should be a minimum 6mm gap between the inside face of the door frame’s

AIR TIGHTNESS

Manthorpe Loft Door 60mm Insulation, Air Tight & cost-effective alternative to traditional roof space access

Efficient measured indoor air ventilation can only be attained if the building shell is airtight. In a leaky building, air flows through cracks and open junctions, but this is uncontrolled and depends largely on wind

direction and the prevailing weather. Also, it is vital when refurbishing an existing dwelling that the building shell is airtight.

WINDOWS

New windows should be positioned on a bed of mortar with the rear of the frame in the same location as the existing window’s reducing the amount of disruption required within the dwelling. Once positioned, fix through the frame into the brickwork ensuring packers are placed between the frame and the wall at the fixing locations to offer maximum support.

WATER CONSERVATION

Waste Water Heat Recovery Unit

Using water, especially hot water, uses energy and increases emissions of greenhouse gases contributing to climate change. Within the Code for Sustainable Homes (CSH) there are challenging water usage targets that require the installation of very low flow taps and shower heads and may also need non-potable water

supplies from collected rainwater or greywater from baths and showers.

MECHANICAL VENTILATIONWITH HEAT RECOVERY SYSTEM

Greenwood Fusion - A range of energy efficient whole house heat recovery ventilation systems, for apartments and houses.

Mechanical Ventilation with Heat Recovery (MVHR) provides ventilation to the living areas and bedrooms. The heat is

recovered from stale air drawn from bathrooms and utility rooms.The MVHR system has minimal maintenance. Mechanical Extract Ventilation (MEV) provides the continuous extraction of stale, damp air from all wet rooms such as kitchens, bathrooms and utility rooms. MEV systems are suitable for a wide range of buildings, from apartments and houses to student accommodation units and nursing homes. MEV systems can be designed to ventilate either an individual apartment or several apartments simultaneously. MEV systems can be used in place of a fan under Building Regulations and you can gain a better SAP rating.

Glow-Worm Heat Recovery

PHOTOVOLTAIC PANELS

Photovoltaic Panels (PV), often referred to as modules, use multiple cells joined together to convert solar radiator into electricity. A PV cell consists of one or two layers of a semi conducting material usually silicon. When light shines on the cell it creates an electric field across the layers causing electricity. PV cells are either classified as crystalline or thin film. Arrays of panels are known as a string. The number of strings used depends on roof space and the

capacity of the inverter. Most inverters can handle 2 strings and the panels should be divided equally between both strings. The inverter must be placed as close to the panels as possible to avoid loss of efficiency.

Dimplex PV Modules

AIR SOURCE HEAT PUMPS

Air to water heat pumps use the constant energy available in the air with a refrigerant circuit to create warm water.

Heat Pumps use refrigeration technology to provide heat from a condensing unit. The evaporator side of the heat pump absorbs energy from the air outside the house using it as a source of heat. The efficiency of a heat pump is denoted by its coefficient of performance known as ‘CoP’. This is the ratio of energy extracted from the source and energy used by the heat pump itself. Typical CoP values for ground source heat pumps are 3.5-4.5, whereas air source heat pumps tend to have a CoP of between 2.5-3.5. With the current mix of fuels for electricity production, using a heat pump produces slightly less emissions compared with conventional gas heating.

GROUND SOURCE HEAT PUMPS

Ground Source Heat Pumps (GSHP) utilize the heat energy stored in the ground to heat water that can be distributed to the taps, appliances and heating systems within a building. The GSHP works by passing the low energy heat captured from the ground through a refrigerant cycle that converts it into higher temperatures for use within the home. The heat is collected via means of a loop array that may either be placed in a trench (c.1.5-2m deep). GSHPs can also be

used for summer cooling.

BIOMASS HEATING

When compared with fossil fuels, like oil, gas or coal, biomass is a sustainable carbon neutral fuel. A Biomass boiler offers an environmentally sound heating solution as it emits on average the same amount of carbon dioxide that is absorbed by plants, thus having little or no adverse effect on the earth’s delicate C0² balance. Biomass has been used as a source of heating by many generations in the form of wood-burning stoves and open fires. Recent advances in technology have led to the

development of new types of boilers that use biomass cleanly and efficiently to heat both space and water. Biomass boilers reduce energy consumption - resulting in lower energy bills, especially in the face of the rising cost of traditional fuels.

SOLAR THERMAL

Solar water heating systems use solar panels, called collectors, fitted to your roof. These collect heat from the sun and use it to

heat up water which is stored in a hot water cylinder. A boiler or immersion heater can be used as a back up to heat the water further to reach the required temperature. There are two types of solar water heating panels. They are evacuated tubes and flat plate collectors, which can be fixed on the roof tiles or integrated into the roof. Most conventional boiler and hot water cylinder systems are compatible with solar water heating. But if your boiler is a combination boiler (combi) and you do not currently have a hot water tank, you would need to install a twin coil cylinder.

HIGHLY-EFFICIENT BOILERS

Boilers account for around 60% of what you spend in a year on energy bills, so an efficient boiler makes a big difference. Replacing an old gas boiler with an A-rated high-efficiency condensing boiler and improving your heating controls will significantly cut your home’s carbon dioxide emissions.

GREEN DEAL MEASURES

A Green Deal Measure is an “improvement” made to a property which has been financed through the Green

Deal. This is the indicative list of measures which are likely to be in the final Green Deal plan:

EXAMPLE OF GREEN RETROFIT BUILDING:

EMPIRE STATE BUILDING

ASIAN DEVELOPMENT BANK PHILIPPINES

NUVALI ONE EVOTECH

THINK BEFORE YOU RETROFITRetrofit shouldn’t be first choice, but considering how you occupy buildings and gradually progress through easy and quick solutions before implementing major interventions is the right approach for buildings, their occupants and the planet.

Step One: Easy changes to life style and reducing need for energy:•          Wear additional clothing and turn heating down in the winter.•          Quicker showers - no long baths.•          No tumble drier - using a washing line.•          Turn off radiators in rooms not or seldom used and close doors to keep heat within occupied rooms.•          Keep a smaller fridge - use a larder or cool room as an alternative to a larger fridge.

Step Two: Further changes to life style and reduce energy use:•          Use heating controls properly - turn off heating when not needed.•          Close curtains and shutters if they exist in winter - when practicable.•          Only boil just enough water that is needed in a kettle.•          Turn off appliances at wall socket when not in use.•          Close doors to all rooms - lock heat in rooms that are used most.

 Step Three: Reduce energy use via Low Cost relatively easy Retrofit improvements:•          Ensure that the external building envelope is properly maintained.•          Ensure that any plumbing leaks are promptly repaired and possible bathroom water spills are properly managed.•          Low energy lighting.•          Insulate hot water cylinder.•          Loft insulation.•          Draught proof doors and windows.•          Thermostat valves to radiators.•          Secondary glazing to windows (note that this can provide better thermal insulation than new double glazed).•          Replacement appliances with energy efficient models when it is time to replace them.

Step Four: Reduce energy use via Higher Cost Retrofit improvements:•          Energy efficient boiler.•          Shutters to windows.•          Floor insulation.•          Upgrade windows.•          Solar thermal (hot water) panels.•          Solar photovoltaic (electric) panels.•          Wood burner - if wood is easily available.•          Ground/ Air source heat pump.

•          Wall insulation.

ANALYZING THE OPTIONS

Not all the options listed above will be suitable and some will be more suitable than others. The advantages and disadvantages will have to be analysed with a detailed options appraisal considering  a wide range of issues.Generally retrofit has the following advantages and disadvantages:Advantages include:•          Making buildings more suitable for their intended use by improved thermal comfort.•          Making them more energy efficient -  lowering related carbon emissions.•          Long-term sustainable use of the embodied carbon investment.Disadvantages include:•          Costly and possibly inconvenient.•          Reducing the internal floor space if interior wall insulation is incorporated.•          Not all risks are always fully understood and it is possible that retrofit could create greater carbon emissions if it results in deterioration of the existing building fabric that subsequently has be to repaired.•          Simple and least expensive options are not always given priority on all occasions and the steps highlighted above are not always taken in a logical way.•          Doesn’t always focus on the basic fundamentals of keeping buildings in good repair to make them last as long as possible and as a contribution to their energy efficiency.

CONCLUSION

•       Keep buildings in good repair - ensure moisture cannot become trapped within the building fabric.•       Take logical steps and do the simple, easiest and least expensive things first.•       Seek sound independent expertise and take proper account of product manufacturers.•       Caution is required in any decisions made relating to insulating existing building fabric, particularly walls.•       Training and education is essential – including understanding of maintenance and repair requirements.•       It’s not just about energy reduction - consider risks as well as benefits.