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  • United Kingdom
  • London


Contact Information

Chris Dunham
Carbon Descent
United Kingdom

The London ECOSTILER community is based in the London Borough of Lambeth. ECOSTILER in London has demonstrated the successful refurbishment of three high rise tower blocks that has achieved an 80% reduction in carbon emissions of a typical three bedroom flat and the landlords footprint..

Lambeth is one of a ring of fourteen inner London authorities. The Borough has its northern boundary on the river Thames and extends 11km south; Lambeth measures 4km across.

Like other inner London Boroughs, Lambeth has seen its population grow in recent years and is currently one of the most densely populated areas in London. The Borough’s population has expanded from 250,000 in the 1990s to 272,000 in 2006 with the population projected to reach 332,000 by 2026.

The CONCERTO approach: 

The ECOSTILER community in the London Borough of Lambeth demonstrates an eco-refurbishment of high rise tower blocks that were built in the 1970s.

ECOSTILER in Lambeth also involved installing solar thermal and solar photovoltaic technologies on schools, training and development of professionals in the sustainable buildings sector, the creation of a suite of learning resources for local residents and energy audits and advice for local businesses.


ECOSTILER in Lambeth involved installing solar thermal and solar photovoltaic technologies on six primary schools, a feasibility study that investigated the potential for a Lambeth ESCo (Energy Services Company), a biogas feasibility study and a programme of research and training aimed at professionals in the sustainability sector.

ECOSTILER in Lambeth showcases the eco-refurbishment of  three tower blocks that were constructed from modular concrete units in the 1970s. The refurbishment included insulated cladding with photovoltaic panels, a green roof, a 357kWe CHP unit, new wet radiator systems with temperature controls, new boilers and the upgrading of the double glazed windows.

Site facts and figures: 
  • Estimated population involved: 10,000
  • Approx. geographical area coverage: 71.2 ha
  • Approx. energy saving: 10%
  • Approx. energy from RES (in %): Information will follow

Lesson Learnt

The following information has been gathered as part of the CONCERTO Premium policy research.

Benefits of CONCERTO:

The CONCERTO Project was unusual in that it was not just about technological solutions for climate change. In order to create truly low carbon communities, the project went a step further, actively engaging with the local community and encouraging and inspiring the residents living within the CONCERTO communities to take action. Overall, the project has been incredibly well accepted by the residents and they are very happy with the improvements made to their homes. After the eco-refurbishment project had been completed, the socio-economic study revealed that residents were much prouder of the estate as a place to live and felt much higher levels of satisfaction with their flat.

Skill development:

Trainees from within the local community were given the opportunity to receive customized training on the professional construction disciplines on the project. The headline results show that overall across all the schools, awareness of climate change, energy efficiency and environmental issues increased over the duration of the project. The percentage of students who understand what a solar panel is and what its function is rose from 46% before the project to 92% after the project. The number of staff who said that they felt confident teaching about environmental issues rose from 35% to 53% across all the schools. Among families of students at the schools, the number of families that performed more than two environmentally friendly actions as part of their lifestyle rose from 51% to 87%. Two workshop events were held with 60 attendees each coming from academia, policy making and practitioners with a focus of achieving 2050 emission reduction targets and focused on technical details of condensing technology and heat networks.

Barriers encountered:

Administrative barriers:

A lack of cooperation and acceptance between departments within the public administration was noticed. The Council had been skeptical about participation in a European project, as it was perceived to be labor intensive due to administrative requirements. However, they became convinced as due to the additional CONCERTO funding a higher energy efficiency standard could be achieved and additional measures (PV) could be implemented. Procedures to obtain permission for RES took long.  The project planning and technical implementation-took longer than expected, leaving less time for monitoring (S.9). Therefore, the project plan was changed to include more refurbishment measures and solar RES instead.

As part of Lambeth’s Low Carbon Zone, six large businesses have been recruited to receive energy audits and advice on how they can reduce their energy consumption. Common findings revealed through the audits are that none of the businesses undertake regular measuring and monitoring of their energy use and staff awareness of energy issues is low.

Technical barriers:

Planned roof-mounted wind turbines are not feasible due to low wind speeds recorded on two sites.

Economic barriers:

The capital costs of renewable energy technologies are still high and so difficult to justify in a recession period. The Council was looking for additional funding to refurbish one of their estates (Ethelred) where they already got funding granted under the GOL (Government Offices for London) and internal capital resources. Difficulties have been experienced due to the variation in ownership (~20% are leasehold properties i.e. the properties are not owned by the Council). In these properties, the owners are forced to pay a share of the construction work. CONCERTO provided additional funding.

Social barriers: 

No tenants showed interest in energy efficiency generally. There was some only regarding the work on the district heating systems due to safety fears (in the past one block of flats had had to be demolished due to an explosion in a boiler house). The rebound effect occurred as energy savings do not materialize despite EE-measures, as occupants simply enjoy the greater comfort that has become possible. The rebound effect was very pronounced in Lambeth – calculated carbon savings were around 80%. However, the gas consumption in one of the blocks (Ethelred) has hardly changed despite new CHP plant and insulation measures, as residents heat to higher temperatures than those calculated with. However, some limited behavioral change could be delivered and a small reduction in electricity consumption could be achieved.

Success factors identified:

Technical Success Factors: 

A quest for optimal metering and controls was part of the project, to achieve low return temperatures and methods to detect leakage in systems in order to obtain thermodynamic advantages of direct connection. Vacuum and Nano gel insulation were tested for pipes and vessels. The fact that the heat load on one of the estates (Roupell Park) was reduced due to energy efficiency measures, the district heating has now surplus capacity, which is being supplied to nearby terraced housing. Low temperature district heating can achieve a COP of 12-16 in order to maximize condensing effects. Expert engineering support was available due to links to research. Usage of external heat exchangers on hot water systems was successful.

Social Success factors:

It has proved to be helpful to do awareness raising in the adjoining schools as the children ‘teach’ their parents of the benefits of energy efficiency. Understanding the ownership issues (leasehold versus social housing tenants) and their particular needs must also be considered earlier on in the design process to avoid conflicts. The level of awareness of the existence of environmental issues is relatively high, suggesting that residents would be responsive to programmes supporting energy efficient behavior. In fact, some small successes could be achieved in small reductions to heating temperatures and electricity consumption.

Institutional success factors: 

The CONCERTO-measures were combined with general refurbishment measures under the UK “decent homes programme”, improving quality of living all-round.

Economic success factors: 

The Decent Homes company cost-effective analysis was used as the base for investment decisions.


Flexibility of EC-Officer when Project had to be changed (moved from Southwark to Lambeth).

Business models used:

Esco-model has been investigated , but not been pursued – Lambeth retained ownership, maintains the plant and sells the energy to a utility company (no feed in tariff was available, as this is only available, if no grants were received for the installation).

Legacy – follow-on projects:

The local coordinator is taking the expertise gained to a new project: “Hide Farm”, another residential project in Lambeth.

Legacy - Policy Developments:

Findings regarding CHP in conjunction with low temperature district heating have been discussed with the team responsible for the s-called UK 2050 pathway (their current plans indicate significant investment in retrofitting CHP DH to meet 2050 targets).


At the London borough of Lambeth innovative condensing CHP (Combined Heat and Power) is demonstrated, fuelled by both biogas and cooking oil. In addition to electricity and heat, this plant additionally generates nutrient for plants in form of CO2 at the plant nursery. Further CHP systems have been installed at the Roupell Park Estate and the Ethelred Estate (in total 357 kWel).

The district heating system of Ethelred Estate has been refurbished, 297 apartments at the three
high-rise towers of the Estate have been retrofitted by energy saving measures such as insulation, double glazing, efficient lighting and a green roof (Picture 1). Several occupants got energy display meters installed to provide them with feedback on their electricity consumption and the temperature of the flat.

A void property from the Victorian time (constructed of massive walls) has been chosen to demonstrate a refurbishment for reducing the carbon emissions by 80%.

Within the “Solar Schools” Task six schools have been equipped with 6 kWp PV systems, about 5 m² of solar thermal collectors and a weather station (Picture 2). They now have a total of 32.25 m² solar thermal systems and 37.86 kWp of PV installed. Photovoltaics of 63 kWp were installed at “Brittany Point”, one of the Ethelred Estate towers: the south-facing wall has vertical photovoltaic panels attached to the insulated cladding system. Twenty kWp have been installed at “Mursell court”, further 10 kWp are installed at another estate, which is still to be defined.


Refurbishment of Ethelred Estate

The Ethelred Estate was constructed
in the early 1970s and includes three
high-rise towers made from modular interlocking concrete blocks. As well as installation of a new CHP plant and upgrade of the existing district heating network (Picture 3), further energy saving measures have been performed.

Over a two-year period, the buildings were completely refurbished inside and outside. New windows, new ventilation systems, new radiators with individual controls, an insulated cladding system and render have been installed. The windows are double-glazed with white powder coated aluminum frames and trickle vents for ventilation; the breasts below have insulated panels now. Residents can now program their heating and use individual radiator thermostats, improving their thermal comfort (Picture 4). All flats have been rewired and have low energy lighting fitted throughout, helping the residents save money on their electricity bills.

The south-facing wall of “Brittany Point” now has vertical photovoltaic panels attached to the insulated cladding system (Picture: London, Ethelred Estate). Sedum mats have been laid over a waterproof membrane on the roof. As well as providing insulation, sedum ‘green’ roofs now promote biodiversity on a densely built up area of inner London.

Overall, the project achieved an average of 80% reduction in the carbon footprint of the flats and now only 7.6 % of residents report that they were unable to heat their homes to a comfortable temperature . 95% of residents are now fairly or very satisfied with their dwelling as a place for living.

CONCERTO technologies

Renewable Energy Source: 
  • Biogas
  • Sun
Low Carbon Technologies: 
  • CHP with Biomass Fuel
  • District Heating and Cooling
  • ICT
  • Mechanical Ventilation and Heat Recovery
  • Optimised lighting
  • Photovoltaics
  • Thermal collectors

SRT data