Our housing developments are developed with sound environmental principles and sustainability in mind from the very start. High quality design is an integral part of sustainable development. Sustainability is about creating a place which not only has low carbon emissions, but one where people will want to live, and which is healthy, attractive, safe, encourages walkability and is secure.
All of the design points discussed above form the basis for sustainable development. In terms of minimising CO2 emissions, we believe that building a home with a low energy demand is the best long-term way to deal with high CO2 emissions and fuel bills. The efficiency of the building envelope is key to this, in terms of insulation, minimal thermal bridging, good airtightness, efficient ventilation and an efficient heating system. The external envelopes of the dwellings i.e. walls, floor, roof, windows and doors, will be insulated to a high standard. All insulation materials will have a GWP of less than 5 and an ODP of zero.
In addition, CG Fry & Son have developed bespoke construction details which have been designed to minimise repeating thermal bridging. Providing a well-insulated building envelope, which does not loose heat through thermal bridging, is the first step towards reducing energy use.
To assist further with minimising energy use, our policy is to make maximum use of free and renewable energy from the sun to pre-heat the building fabric during periods of high solar gain. In accordance with Passive Solar Design principles, the orientation and internal layout ensures that, where possible, all daytime living rooms such as kitchen/family room, dining room and living room will benefit from passive solar gain. The external walls of the dwellings will be traditional cavity wall construction, which utilises the high thermal mass of the structure to store heat for later release. Where possible, floor plans are dual aspect to allow passive solar gain.
Where possible, larger glazed areas are positioned on the south elevation, while smaller glazed areas are positioned on the north elevation. Free solar heating will be absorbed by the structure and released into living areas as the temperature drops to help reduce the demand on heating systems. Due to the larger sized south facing windows, the houses will also have good levels of daylight, creating pleasant internal spaces and minimising the use of artificial lighting. A high thermal mass building fabric is also less susceptible to external temperature change and to increased global temperatures than lightweight construction methods.
Correct airtightness coupled with adequate ventilation also forms an important part of our energy reduction strategy. The reduction in unwanted heat loss through air leakage and draughts can have a significant effect on CO2 emissions - it is estimated that existing older homes can lose up to 45% of their heat through air leakage. All CG Fry new homes are airtightness tested on completion by an independent assessor. The maximum leakage allowed by Building Regulations is 10m3/m2/Hr - CG Fry and son achieve an average airtightness result of 3.75m3/m2/Hr across all their sites.
Obviously with reduced levels of natural ventilation and draughts, it is vital to provide the correct amount of controlled mechanical ventilation, to avoid moisture build up and condensation within the home. CG Fry and son use continuously running extractor fans which are designed to achieve the required ventilation depending on the m3 volume of the house, but without extracting too much heat from the property. This is the most efficient method of ventilation without resorting to overly complicated mechanical ventilation systems.
An efficient central heating system will be installed, using condensing boilers with time and temperature controls, and dual zone control to daytime living areas and bedrooms.
100% Low energy internal and external lighting will be provided throughout. Low flow taps, showers and dual flush WC’s are also provided which reduce water consumption while not compromising on performance..
In addition to other energy saving measures such as low energy lighting, low water use, cylinder insulation, condensing boilers, low-e double glazing, better heating controls, our houses are designed to reduce noise transfer through party walls. Noise transfer between houses is reduced by providing sound insulated separating walls.
Products will be used which are made from recycled materials or which make the best use of raw materials e.g. an engineered joist system for first floor construction allows the manufacturers to convert much more of each tree log into structural timber than with traditional sawing. All timber comes from certified suppliers and where possible local materials are used to reduce transportation. All elements, products and materials achieve sufficient U-Values to exceed the minimum energy requirements outlined in the building regulations. Reclaimed demolition materials will be used where possible, including crushing existing concrete on site for use as hardcore for paths, roads and sub floor bases. Similarly, engineered prefabricated roof trusses will be used, which are much more efficient in their use of raw materials than conventional cut roofs.