Existing dwellings are increasingly recognised as one of the key barriers to major reductions in CO2 emissions.
Where this comes most sharply in focus is where dwellings have heritage value. The very heritage in bricks and mortar often has poor thermal performance. The aim of this project is to reduce CO2 emissions from a Victorian building in a conservation area in the London Borough of Camden by 90%.
The project will provide valuable information to show how the wider housing stock in the UK can be refurbished so that they approach zero energy levels. In so doing it will help preserve the nation’s heritage and make existing communities sustainable without demolition.
The Low Energy Victorian House Project, led by Camden Council, aims at refurbishing a solid wall semi-detached Victorian house located in a conservation area to achieve a 90% reduction in the house’s carbon emissions. This project will result in low energy social housing for a large family, as there is a shortage of this dwelling type in most of the councils’ housing stock.
It also attempts to preserve some of the house’s most important heritage features.
The sustainable refurbishment programme
The house has solid brick walls and an uninsulated roof. The ground, first and second floors window openings are originally single glazed timber sash, whilst the basement has modern timber framed single glazed windows. Most frames are in good condition apart from the paintwork.
As far as the doors are concerned, the entrance front door is original solid main timber framed, internal doors are original, the basement flat has a modern half glazed entrance door, and modern timber glazed doors to rear garden.
The front and flank elevations have painted render with decorative mouldings around the windows. Indoors, the rooms are decorated with valued internal finishes, including plasterwork.
The project sought to conserve many of these existing features and a number of options were considered of the house during the preparatory workshops, especially regarding windows and insulation work.
Pros and cons regarding both heritage value and energy saving measures were discussed among the project’s stakeholders. However, the tension between the building conservation and energy saving could not be totally resolved.
A range of measures was agreed upon, which emphasised energy saving and maintenance concerns and the construction work is scheduled to start before December 2007. Their projected U-values and their purchase and installation estimated cost are given below:
|Measure||U-Values (W/m²K)||Cost (£)*|
|Double Glazed windows||1.5||500|
|Wall insulation||0.20||Donated by Kingspan|
|Solar thermal panels||8,000|
|Solar PV panels||31,500|
|Localised heat exchange ventilation||2,000|
* Those are the estimated additional costs to part L requirements, and do not include consultancy and fee charges (+25%)
Considerations about future maintenance are taken into account and, wherever it is possible, the fixings will be chosen to be as user friendly as possible.
Other technologies were been considered but were rejected for the following reasons:
- Budget: The incremental benefits of triple glazing system were not judged significant enough to justify its additional up-front cost. The idea of installing a 3,000 litre rainwater harvesting tank was abandoned for a similar reason.
- Space: The house did not present enough space to install a ground source heat pump, and low environmental impact wood-wool insulation has been abandoned because of its thickness that would have further reduced the available living space.
- Planning and conservation regulations: the over cladding of the side and rear of the house did not receive planning clearance.
Research and dissemination
The project also provides an opportunity to research, experiment and report on the outcomes of the various fittings implemented to rehabilitate the house. The Bartlett Faculty of the Built Environment (UCL) is undertaking an academic survey of the whole project.
Features such as temperature, humidity in walls, pressure and co-heating test and fuel use will be monitored until winter 2008. Access of the monitoring team to the various meters and data will be part of the tenancy agreement.
To evaluate the overall improvement of the building, it will be monitored after its refurbishment and during habitation. The collected data will be compared with the average performance of an un-refurbished house of the same street whose fabric will be similar to the 17St Augustine’s.
The Camden Council has also established a steering group of key stakeholders to discuss and debate the implementation and outcomes of the project.
London Borough of Camden provides the core funding of the project to bring the house back to use as a large council house. The Energy Centre for Sustainable Communities is also providing financial support to the project.
Research and dissemination of the monitored results and analysis are conducted by the Bartlett Faculty of the Built Environment (UCL) and funded by the UrbanBuzz.