Sustainability – Preserving Britain’s Housing

According to the Department of Communities and Local Government, domestic housing accounts for some 27 per cent of the UK’s carbon emissions. The Code for Sustainable Homes was developed with the aim of reducing this level through the building of sustainable new homes - but tackling the refurbishment of UK’s existing homes is not so clear cut.   

Furthermore, 50 per cent of existing homes in the UK are more than 50 years old and it is believed that around 90 per cent of today’s homes will still be standing in 2050 – the year of the Government’s target for an 80 per cent reduction in greenhouse gas emissions, according to BRE.

Add to this reports that house building levels have been falling and the importance of refurbishment and maintenance of the UK’s existing housing stock is brought to the fore.

At present, BRE says 20 per cent of UK properties are more than 100 years old - typically built with single skin walls and no damp proof course, sash windows and single glazing.

Such housing can be damp and draughty by today’s standards – costly and inefficient to keep warm.  However, by demolishing this type of housing and rebuilding new, we are contributing to the vast amount of building waste that needs to be disposed of, or reprocessed.

Bringing such properties up to an acceptable standard for today’s market, while keeping sustainability in mind, can be something of a challenge, but according to Stephen Hodgson, General Manager of the Property Care Association (PCA), the technology is out there to do so – it simply needs an understanding of how older properties work.

“Professional, considered and targeted preservation techniques – such as timber repairs, the elimination of damp problems and structural stabilisation - often play a key role in the refurbishment and maintenance of our existing housing stock,” says Stephen.

“This type of work preserves and protects what we already have, with a minimal impact on the environment and resources.”

Many of the problems with older housing – condensation, damp, rot and to a degree timber infestation – arise from excess moisture within the fabric or the interior of the building.  However Graham Coleman, an independent Consultant and Expert Witness in timber infestation and dampness issues – and a member of the PCA’s Technical Panel - stresses the importance of taking time to fully consider each situation, so that a solution can be achieved with minimum disruption to the structure of the property and its occupants.

“Each case must be assessed individually and ‘if it ain’t broke, don’t fix it’,” advises Graham. “Where the problem is due to rainwater ingress, then it is essential the cause is fixed first, the building allowed to dry out and then a reassessment made, followed by targeted treatment if necessary.  If structural timbers are still sound, then there should be no need to remove them.

“With any treatment of rot or timber infestation in older and in particular heritage buildings, it is important that as much of the original timber is retained as possible, as long as the structural integrity of the building is maintained.
Original timber is often of a higher quality than that available these days as it was generally slower grown, resulting in a higher proportion of rot-resistant heartwood.”

With this in mind, in heritage buildings there may be a case for drying out over several months and then monitoring the situation into the long term, but this is rarely a practical solution for domestic housing or for projects where time constraints are imposed by clients or developers. However, targeted preservative treatment can be a very cost-effective method of timber treatment, particularly where large-scale removal of structural timbers would otherwise be necessary. Targeting just the affected area means that a room is only out of bounds for a few hours.

Where it is necessary to remove damaged wood it is not always necessary to remove the whole structural element. Modern techniques include the use of resin to replace damaged wood in situ – with steel reinforcement if necessary – which can be stained and textured to match the original timbers.

According to Stephen Hodgson, the development of resin repair techniques, cementitious anchoring systems and helical technology has enabled cost effective structural stabilisation to be carried out without the need for costly and resource rich demolition and rebuilding.

He said: “Using these novel approaches to the stabilisation of cracked and unstable structures allows reliable cost effective rectification to be undertaken quickly without affecting the look or character of the building. 

“Draught proofing also needs careful consideration and, in older properties, it must be done sympathetically. While we should not need to live in damp homes, such properties, due to the way they are constructed, generally require a degree of moisture movement and an appropriate level of ventilation.  Single skin walls and the use of building materials which are more porous than those used to today, mean that rendering or painting walls in older properties with modern, non-porous coatings can hinder the free movement of moisture within the building and might even be the cause of damp problems. 

“In older buildings, chimneys, sash windows and a less airtight construction readily allow air exchange, but if during a refurbishment the aim is to simply remove all draughts, then condensation can become a real problem in these properties as well.

“It is widely acknowledged that condensation is the most common cause of dampness in buildings, resulting in spoilt decorations and damage to clothes and furnishings. The use of well placed insulation, passive air exchange systems and in some circumstances the use of more active indoor air management systems can be highly effective in controlling condensation.

A key issue stressed by the PCA is the importance of using fully qualified professionals to survey and undertake refurbishment works on older properties – and in particular to use contractors with experience of working sympathetically with the specific attributes of such a building.

The PCA has a wealth of specialist technical advice available to members on the internet, which is continuously being extended and reviewed.  In addition the PCA’s Technical Panel, a group of property care experts with a broad range of expertise, is available to respond to technical questions from both industry professionals and members of the public.

Separate box
The report on the 2007 English Housing Condition Survey has some interesting findings from across the private and social housing sectors.

Some 8.6 million (39 per cent of) homes in England were built before 1945, including 4.5 million built before 1919.  While there is considerable variability, the oldest homes generally performed less well than newer housing regarding their condition and energy performance. The proportion of homes with damp problems reduced from 13 per cent in 1996 to nine per cent in 2007.

Just under 35 per cent of dwellings in England in 2007 were classed as non-decent.  A decent home being classed as one that meets all the following four criteria:
1) Meets the statutory minimum standard for housing – the Housing Health and Safety Rating System.
2) Is in a reasonable state of repair.
3) Has reasonably modern facilities and services.
4) Provides a reasonable degree of thermal comfort.

Download the report free from:
http://www.communities.gov.uk/publications/corporate/statistics/ehcs2007annualreport

Separate box

As with most problems, prevention is better than cure and maintenance is key to ensuring the rot does not set in with any property – old or new. Keeping gutters clear and repairing broken rainwater goods, as well as making sure flashings and pointing are in good condition, is far more cost effective than having to deal with a case of wet or dry rot at a later date.

Keeping air bricks free from debris to allow ventilation of suspended timber floors and making sure loft insulation – a key factor in improving the thermal properties of a building – does not obstruct ventilation of the roof space via the eaves are important considerations.

Separate box

BRE is undertaking a £4.5 million project to refurbish and carry out extensive research and development on three Victorian terraced houses.  The project will demonstrate innovative retrofit solutions that are designed to reduce, by up to 80 percent, carbon emissions from existing homes.

The Victorian Terrace will undergo a programme of before-and-after testing and monitoring to establish the impacts of this work, from which a series of refurbishment specifications will be developed.  In addition the Victorian Terrace project links to more than 350 exemplar refurbishment  homes of varying types and age around the country, test results from which will also feed into the new specifications, monitoring protocols and best practice guidance.

More information about the Victorian Terrace project is available at www.rethinkinghousingrefurbishment.co.uk

BRE is developing a new standard under BREEAM to cover domestic refurbishment.  For information see www.BREEAM.org/domrefurb