With new housing adding only one per cent to the stock each year, improving the environmental performance of existing homes can make the biggest difference to carbon emissions and energy consumption.
But working within the physical constraints of an existing building and encouraging the owners to take on added expense when improving or refurbishing their homes poses a major challenge.
The new edition of the Sustainable Housing Design Guide for Scotland published last month by Communities Scotland has been extended to look at refurbishment issues. The guide argues that the decision to demolish housing is often taken without taking into account the environmental and social impact and suggests that “refurbishment is not always straightforward, but best design practice can easily match the performance and quality of newbuild at greatly reduced costs.”
One of its authors Fionn Stevenson from Dundee University says that when refurbishing housing, it is important to address all the elements of a house which have an impact on the environment.
“It is not effective just to address one area, you have to do a bit of everything.” She emphasises the importance of not just putting in high levels of insulation and an efficient heating system but also securing the air-tightness of the building.
“Without air tightness the air changes between five and ten times an hour losing much of the heat in the home. If it is air tight, that drops to around once an hour.”
The funding available is not helping a comprehensive approach. There are a large number of grants available, she says, but they are too fragmented, offering support to one element, wind turbines or heating systems and not offering packages meeting all the needs of the homes.
The lack of effective environmental standards for refurbishment programmes is a cause for concern. The Government introduced in England the Decent Homes Standard, which requires the improvement of all existing public and housing association housing to a basic condition by 2010. Stevenson suggests that the standard is too low and does not address all the environmental issues. “It concentrates on warmth, insulation and other amenities such as kitchen equipment not on air-tightness,” she says.
Paul Greenwood who is best practice manager at United House which manages construction contracts for local authorities and housing association points out that the Building Research Establishment has developed Ecohomes XB standards for refurbished housing, however as yet there is no requirement for its implementation. He suggests that a code for sustainable homes is required for refurbishment in the same way as the new code is being developed for new building. The Government is reviewing the decent homes standard with a view to extending its scope. Greenwood hopes that it will address more effectively environmental issues. A recent review for the DCLG on the operation of the Decent Homes Standard called for new guidance for housing providers.
It suggested that sustainability issues had taken a back seat due to other pressures such as time and limited budgets. The report proposed that “to push it higher up the agenda, the government needs to consider whether and how far they should specify or encourage the use of environmentally sustainable materials and components in refurbishment. Government should also consider promoting good practice on the disposal, recycling and reuse of materials and components removed from homes as a result of works.”
In many situations, particularly when tower blocks are involved, there is a temptation to opt for demolition. The guide says that the advantages of sustainable refurbishment are that it is a cheaper alternative to new build. It is a cost-effective alleviation of fuel poverty, there is a financial payback through reduced service and maintenance requirements; it secures the cost-effective upgrading of local neighbourhood, improving existing local identity.
It preserves the existing building fabric so minimising use of raw resources. It achieves the increased airtightness and control of ventilation to provide condensation-free dwellings. It reduces the number of voids in housing stock and creates an improved sense of place and less community disruption.
It urges that sustainability issues should be incorporated into refurbishment programmes in a strategic way. The starting point for any sustainable refurbishment programme should be for the housing provider to develop policy and guidance on sustainable refurbishment as part of its overall sustainable development policy. This should link directly to the auditing and targeting of existing stock for improvement.
“Your next priority is to identify which homes would benefit from refurbishment in terms of environmental, social and economic considerations, using EcoHomes 2006 or similar standards to help set the brief for the design team on any major refurbishment projects.”
Paul Greenwood says “It is surprising but many local authorities, housing associations and arms length management organisations do not have a good idea of the condition or the environmental performance of their housing stock.”
The starting point for many sustainable refurbishment programmes is fuel poverty and some quick wins highlighted in the report are upgrading insulation and installing energy efficient boilers. More strategic refurbishment programmes can set new standards for the organisation in the environmental performance of their housing which might include improved glazing and district combined heat and power schemes.
The report however emphasises the importance of simple solutions. “You should keep refurbishment measures as simple as possible: maximum insulation, attention to airtightness, controlled ventilation and passive solar design, together with straightforward heating equipment and easy-to-use controls, are the priority.” It warns against using over-complex and unproven gadgetry, except on exemplar projects.
Wider neighbourhood issues are also important. One element often overlooked, but which is a source of major energy consumption, is the transport used by the occupiers and in the construction work. Stevenson estimates that transport makes up about 18% of an individual’s carbon emissions compared to only four per cent on heating.
“When refurbishing a housing estate, a housing association or local authority needs to look at how it can encourage sustainable lifestyles,” she says. This means working with transport providers to see how new services can be provided that reduce the need for car travel. Many housing estates being demolished are peripheral which would require a substantial transport package.
The implementation of this programme relies heavily on the availability of appropriately skilled architects, surveyors and builders. “Professional training has to be improved to reflect these greater demands,” Stevenson says.
http://www.communitiesscotland.gov.uk/shdg
Case Study
The Government initiative to address the problems of areas suffering from low housing demand has gained a bad press because of their commitment to demolish large amounts of housing. One of the initiatives covering Birmingham and Sandwell has sought to demonstrate that the sustainable refurbishment of terraced Edwardian and Victorian homes can be an important tool in retaining population and creating new demand.
The initiative funded by Urban Living has developed an exemplar project with a range of housing associations, which have refurbished 12 homes to achieve higher environmental performance than equivalent new housing. According to Richard Baines, environmental consultant from the Black Country Housing and Community Services, this project has been targeted at the private homeowner. “We have demonstrated that the mover/improver that it doesn’t cost the earth to upgrade their properties environmentally and physically.”
Working with the existing physical structure, high levels of insulation have been incorporated into the walls and ceilings. The loft has been converted. The timbers which were removed for the conversion have been reused elsewhere; solar panels and wind turbines included. This model is now being applied by homeowners in the area around.
Ben Burnett, the environmental project surveyor at Family Housing Association in Birmingham, says that the home which it refurbished as part of the low demand scheme achieved higher levels of air tightness than equivalent new-builds and similar thermal properties.
“There are complexities in fitting thicker insulation on the internal walls around the doorways or if the rooms are relatively small. In that situation you may have to put the insulation on the outside.” He adds that finding the space in the loft for tanks for the solar panels can also pose challenges.
Case Study
Despite the extent of the embodied energy tied up in tower blocks and the environmental costs, many local authorities have been demolishing them, mainly for social reasons. The architect Prashant Kapoor from the engineering consultancy Price and Myers secured funding from the Department of Trade & Industry to develop a website demonstrating sustainable approaches to refurbishing tower blocks.
Kapoor says that with appropriate housing management and allocations policies, many can be refurbished to high environmental standards, equivalent to Ecohomes very good or even excellent. He accepts that tower blocks are not suitable for everybody and some have been built very badly with the use of asbestos which should be demolished. “But there are many which can be rejuvenated. They are potentially highly energy efficient buildings with low surface areas for heat loss. They are suitable for people without children and can offer a supportive social environment particularly for older people”.
The major problems with tower blocks is the façade which many refurbishment programmes are now renewing. “It is important that high levels of insulation are included in the new cladding,” Kapoor says.
Many refurbishment programmes involve district heating systems which are quite energy efficient. Biomass boilers could also be considered. He says that tower blocks are ideal locations for wind turbines or solar panels. “For tower blocks with more than 15 storeys, the wind speed at the top can be more than double that at the ground level.” A feasibility study carried out for Poole Borough Council demonstrated how turbines could be fitted on the roofs. Part could also be converted into gardens or as social areas.
http://www.sustainingtowers.org