The Project

Wilmcote House is a sheltered housing scheme in Portsmouth, featuring three connected 11 storey blocks of 107 residential maisonettes, constructed in 1968. As a part of a major energy efficiency upgrade, Portsmouth City Council (PCC) has appointed ECD Architects to lead the design of a project which will see the complete refurbishment of these residential blocks to meet the EnerPHit standard, the retrofit equivalent of Passivhaus. The result will be a thermally efficient building which will deliver varied, long lasting benefits to residents.


The Challenge

Tenants initially voiced concerns over the inadequate and expensive electric heating within Wilmcote House. Portsmouth City Council took a holistic view in evaluating these concerns and recognised that poor insulation was, in fact, the bigger problem, exacerbating discomfort, increasing energy leakage and the root cause of fuel poverty problems for residents.

In exploring the options with ROCKWOOL and others, Portsmouth City Council felt that a whole building refurbishment could significantly reduce energy costs and consumption and improve the energy efficiency and living conditions within each property.

The aim is to lower the demand for heating within the dwellings by 90% and extend the building’s life by a minimum of 30 years as a result of the improvements. Refurbishment will take place over a two year period, with completion expected in January 2017.

Wilmcote House’s actual construction type posed a further challenge for the project team. The building would have to undergo substantial modification and strengthening to enable the application of effective external wall insulation.

Another challenge for the Council was effective consultation and engagement with the tenants on the scheme. To minimise large scale decanting and excessive tenant disruption, Portsmouth City Council chose to carry out the renovation works whilst the building remained occupied.


The ROCKWOOL Solution

The project has been designed to work towards stringent EnerPHit standards and offers a whole building solution that will improve residents’ standard of living and reduce fuel costs. The key to this strategy is “deep retrofit” through installing multiple insulation measures, including external wall insulation, which will greatly improve the thermal efficiency of the properties and provide a stable and comfortable internal environment for tenants.

ECD have devised an effective retrofit strategy to super-insulate the residential parts of the block based on a combination of several ROCKWOOL insulation products and systems, including a combination of REDArt® External Wall Insulation (EWI) systems, ROCKPANEL façade cladding system, and a selection of the company’s Firestopping and Fire Protection products.

The REDArt® EWI will ensure excellent thermal performance and exceptional air tightness, thereby diminishing the occurrence of draughts, condensation and mould growth, whilst markedly improving standards of occupant comfort. Other works will include roof replacement, installation of triple glazed windows, extension of the living areas and more efficient heating and hot water provision.

The refurbishment will also improve the aesthetic appearance of these prominent blocks and contribute more widely towards the regeneration of the Somerstown area of Portsmouth.

Recent lessons learnt from the energy efficiency improvements carried out at the Edward Woods estate in Shepherds Bush, London, across 754 flats in three 23-storey tower blocks have proved invaluable in strategizing the refurbishment of Wilmcote House. The London School of Economics and Political Science (LSE) interviewed residents of the Edward Woods estate during and after the renovation works for its two reports, High Rise Hope and High Rise Hope Revisited.

Among the most significant lessons resulting from the research was the importance of communication with residents. The second report, High Rise Hope Revisited recommended regular community updates and ongoing support to ensure tenants feel informed of the progress of the works and develop a wider understanding of the objectives of regeneration. Residents of Wilmcote

House were comprehensively consulted on the refurbishment proposals via a series of resident open days and feedback sessions and ROCKWOOL will again work in partnership with the LSE to record and assess the social outcomes of this project.



ROCKWOOL’s solution and long-standing partnership with ECD Architects, the client, Portsmouth City Council and the LSE, is providing the perfect solution. This type of refurbishment scheme can help alleviate fuel poverty whilst achieving marked improvements to the quality of high rise living and transforming the visual appearance of a residential block. It is also a project carried out with meaningful co-operation and engagement from residents and the local community, serving as a best practice benchmark of success for similar projects in the future.

Project Location

Wilmcote House

Portsmouth, United Kingdom

Most of the residents are suffering from serious fuel poverty. This insulation will make an appreciable difference to this issue. Significantly reducing heat loss through the thermal envelope by insulating the building wall alongside other works will help the project meet the EnerPHit standards. The project will improve conditions within all properties, making them feel much warmer and substantially reducing fuel bills.

James Traynor

ECD Architects
Wilmcote House project completed

LSE Social Implications Research

Wilmcote House, Thermal Properties

ROCKWOOL meets EnerPHit standards

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