We have occasionally published articles under the heading 'Looking after our estate'. These contain information that we feel is particularly relevant to the mainly Georgian , Victorian and Edwardian houses that characterise our area. So far we have covered windows, stone garden walls, ironwork and trees.

A new topic deserves attention - how can these properties be adapted to 'minimise their carbon footprint' ?

It may seem that the small contribution that a house can make is pointless. However, houses contribute 24% of UK carbon emissions, and as existing homes will continue to account for about 90% of the total housing stock in the UK reducing the carbon footprint of these is very important. More significant than making the small number of new dwellings carbon neutral. Some 'green' improvements will also reduce running costs, achieving the same or better comfort while using less energy. Low running costs are becoming a factor in house valuations, underlined by HIP Energy Certificates. . So there are financial as well as green virtues in the suggestions made. In some cases Government grants are available. (See Low Carbon Buildings Programme.)

Lifestyles have a major influence on our carbon footprint but this article focuses on the bricks and mortar. Not the 'typical' two storey suburban semi upon which most green advice seems to be based but that more typical of our area. Solid, stone built, usually 3 storey, detached, semi or terrace houses. Some suggestions do not apply to flats, or may not be possible due to leases and legal arrangements.

Major building alteration and repair operations, for example re-roofing and extending, provide an excellent opportunity to incorporate energy saving and energy generating measures that go beyond those mentioned here. However all building activities, however well intentioned, consume energy, so it is important to use 'sustainable' materials, with low embodied energy and from renewable sources. (See National Green Specification)

Steps to a lower carbon footprint

1. Reducing Energy Demand - by good insulation, draught and weather-stripping.

2. Reducing Energy Consumption - by efficient heating equipment and controls, and other services.

REDUCING ENERGY DEMAND

Roofs - Typically slate, clay or concrete tiles on felt and timber rafters. Major source of heat loss, well worth dealing with. Aim for 300mm of insulation in roof space if practical. (Adding insulation to existing buildings can cause condensation if not correctly specified – if in doubt seek expert advice.)

Roof lights – e.g. existing 'original' skylights, typically over stairs. Replace with timber double glazed units, openable for summer ventilation.

Dormer windows - Often lightly constructed un-insulated structures and adjoining roof slopes. Consider stripping down and installing insulation.

External walls - Typically solid, thick, usually brick or rubble stone inside faced with dressed stone externally, with render to side and rear walls. Provide a good heat store, slow to react to temperature change, but exposed north and east facing walls can become very cold particularly when the render is saturated. If doing a major building upgrade worth considering adding external insulation and re-rendering. Internal insulation is a less satisfactory solution, as it does not use the benefits of the wall’s thermal mass.

Floors - Concrete floors to ground floors and basements. Difficult to add insulation, unless installing new raised floor, eg, strip flooring, when insulation can be incorporated in some cases. Suspended timber floors, with ventilated airspace under are a considerable source of heat loss, difficult to deal with unless doing major works. See draughts below.

Draughts - major source of heat loss and discomfort. Review all external openings, even letter boxes and loft hatches. Create draught lobbies if possible, and draught proof external doors and doors to unheated spaces. Ventilated floor spaces can cause considerable drafts if the floorboards are not closely laid – it is possible to have wide gaps filled as part of a renovation and still have the floorboards left exposed. Alternatively, carpets with underlay on hardboard sheeting will also cut out drafts. (Requirements for natural ventilation for gas appliances must be considered when closing draughty openings – if in doubt seek expert advice.)

Windows - Timber double hung sash windows are typical. Their relatively modest size in relation to solid wall makes heat loss through them less important than often assumed. Badly fitting timber windows leak heat and cause draughts. First step - have these overhauled by specialist, who can fully weatherstrip against draughts and noise, and make to easy to operate. It is usually unnecessary to renew the whole window. (Plastic replacement windows never look right and UPVC is now regarded as unsustainable.)

Other measures - Double glazing. Difficult to install particularly if the windows have slender traditional glazing bars, as the thicker glass needs heavier and often obtrusive glazing bars. Secondary glazing – demountable 'winter' glazing in clear acrylic, which can be taken down and stored may be good alternative. Or clear plastic film adhered to the window frame - this needs to be used where the thin film will not be damaged, for example for fixed high level glazing, perhaps the stained glass panels so common in our area.

2. SERVICES and energy consumption.

Domestic energy consumption is heavily influenced by the way we live. This is not RCAS territory! - so we touch only on the home and its equipment.

Heating - most commonly gas boiler and radiators. Now established that modern combination boilers, with zoning, time clocks and thermostatic radiator valves make energy savings that usually justify replacing older systems.

Lighting - use low energy light bulbs or other low consumption sources such as fluorescent tubes. Tungsten 'strip' and spot lights, together with multiple Low Voltage and Halogen lights are energy intensive.

Power - Consider replacing older appliances such as washing machines, fridges with A+ or A rated ones. It is instructive to survey the power consumption all appliances, including those on stand-by.

OUTSIDE

Sustainable drainage - Do not increase the hard, impermeable paved surfaces which add to the discharge of water to public sewers and increase risk of flash flooding. Any new hard surfaces to be porous. (See RCAS Trees book)

Rainwater - Collect rainwater in water butt and reuse.

Gardens - retain and manage existing trees and plant new trees Trees absorb CO2 and pollutants, and assist in cooling streets - important in view of predicted rise in summer temperatures. Compost all possible kitchen and garden waste.

3. RENEWABLE ENERGY

Having done as much as possible to reduce the energy demand of the property, consider renewable energy. Solar Water Heating and Photo Voltaic (PV) micro-generation are currently the most practical for our area. The location, orientation, shape and construction of each property will determine what is possible. The continued rapid increase in all fuel costs is making all domestic renewable energy installations more cost effective.

Solar Water heating is generally first option. This is usually designed to provide 'free' hot water amounting to 50-60% of annual requirement. A roof slope facing more or less south is required for the panel, plus a dual coil hot water storage cylinder of good capacity. This is pre-heated by hot water from the solar panel. Solar water systems are currently considerably more cost effective than PV.

Photovoltaic panels also require to face the sun, usually via a south-facing roof slope. The power generated is fed into the house electrical supply, reducing meter readings pro rata. The electricity supplier is a key player, and various contracts are available to recognise the contribution of the micro generation.

Appearance. Many people are concerned at the visual impact that solar panels may have on their property and the attractiveness of our area. The article by Vas Papastavrou in the January Newsletter showed that it is sometimes possible to locate panels where they are virtually invisible. A significant number of houses have valley gutters, and 'hidden' roof slopes. Panels on side and rear roofs will also have little impact. Due south is the most efficient aspect, but south east and south west are feasible. Panels can also be laid almost horizontal on flat roofs, though shadowing by other buildings, chimneys and trees should be avoided.

In fact, our roofs have been subject to many changes over the last 50 years. Original natural slates have been replaced with tiles, often concrete ones. Many, often over large, rooflights and dormers have been added. Chimneys have been removed or decorated with aerials. Overall these changes cannot be said to have improved the appearance of our area.

Planning control. The Government has just issued new planning regulations for Renewable Energy installations on houses. These provide for different levels of controls for 'ordinary' areas and for Conservation Areas/Listed Buildings. Here is a brief plain English interpretation of the clauses most relevant to our area. 

a.  There is a general rule that no solar panels and equipment may project above the roof ridge, or more than 200mm (8") from a roof or wall surface.

b.  For Houses (not blocks of flats) in non Conservation Areas, no planning application is required for the above installations, regardless of which way they face.

c.  For Houses in Conservation Areas (some 80% of RCAS area) planning consent is not needed for panels that face away from the street. But consent is needed for those facing front and side streets. This means that planning officers will have to decide whether a particular proposal is visually acceptable. Listed buildings will continue to require planning consent for any alteration, including solar panels etc.

We understand that Bristol City Council are drafting a Advice leaflet covering this new planning issue and RCAS hopes to be consulted over this. However residents should always contact planning to check what if any consent is required. (0117 922 3097).

SOURCES of ADVICE and INFORMATION

1.   Energy Saving Trust www.energysavingtrust.org.uk/ Suggested first stop - easy to use and comprehensive information on all aspects.

2.   Create Centre www.bristol.gov.uk/create Visit their Ecohome, with Solar Water heating installed and much other information.

3.   Low Carbon Buildings Programme Phase 1 www.lowcarbonbuildingsphase1.org.uk/ for available grants.

4.   Green Register - for professional advice www.greenregister.org.uk

5.   Greenstreet – worked examples of eco-refurb www.greenstreet.org.uk

6.   RegenSW - for Renewable Energy Suppliers - www.regensw.co.uk

National Green Specification www.greenspec.co.uk/

7.  Sustainable Redland - our local group, founders of the Whiteladies Farmers Market and supporters of individual and local group action for a sustainable future. http://groups.yahoo.com/group/susredland/