The British National Health Service (NHS), which is the largest employer in the UK, has set itself a target of getting to net zero within twenty years. The UK’s first passivhaus medical building, Foleshill Health Centre, provides an important indicator of how net zero could be achieved.
The Passivhaus architect, Tooley Foster, has published an analysis of two other health centres built in Coventry in 2008 in 2014 to show how much energy they would be saving if they had been built to the Passivhaus Classic standard.
Grand Union Village was the first project studied, which had an annual energy bill for the passive house version that was 31 per cent lower than the building actually built, in 2008. It was also nine per cent cheaper on capital costs and 10 per cent cheaper on the construction and maintenance costs, meaning that it was cheaper to build.
Forrest Medical Centre had a construction cost of 14 per cent above average, but its significantly lower energy use meant the whole life cost broke even after 14 years and was 10 per cent lower over the full 25 year study period (a typical lifespan for this type of NHS project).
Foleshill Health Centre
Foleshill Health Centre has two storeys, five consulting rooms, two treatment rooms, offices, a reception area and a waiting room. Costing £3.3 million (A$5.93m), it is a public capital funded scheme for the NHS.
The local health partnership (Community Health Partnerships for the NHS) chose the passivhaus approach because of its overall sustainability ethos with low running costs and health benefits. Passivhaus is an international low energy design standard which has been used to design, build and test over 65,000 buildings worldwide. This is the first time that NHSE/I has approved this type of building for the NHS in England.
The health centre was built on a brownfield site, the location of a former council swimming pool that closed in 2013.
Built with specially designed, off site constructed Portakabin modules using passivhaus technology, Foleshill uses air source heat pumps, no fossil fuels, and has photovoltaic panels to generate some of the energy for the general practice surgery.
It has triple glazed windows and mechanical ventilation with the heat transferred to the incoming air from the outgoing air.
The general practice surgery has an Energy Performance Certificate A rating and is expected to be Building Research Establishment Environmental Assessment Method (BREEAM) Excellent by design.
The building is very airtight – the leakage rate roughly equates to a hole the size of a golf ball across the whole building – and fresh air is circulated constantly. All rooms have filtered 100 per cent fresh air from ducts in the ceiling, supplied from ventilation units that recover heat from stale air leaving the building via the mechanical heat recovery unit. The air is filtered to a similar standard as an operating theatre, ensuring a safe and clean environment (ISO ePM1 – June 2021).
The building has been designed to achieve energy consumption figures of about a quarter of a typical health centre of the same size.
Offsite construction
Internal fit out was completed at the Portakabin specialist manufacturing facility in York, then transported to site to be assembled and installed over three days in December 2020. Using exacting standards of engineering to tolerances of one millimetre, the Portakabin team delivered precise control across every aspect of the project from design to manufacturing; measuring every resource used and any waste generated.
Works duration was reduced by 26.5 per cent with the majority of the fit out completed prior to delivery to Foleshill.
The building is highly insulated, so it is warm in winter and cool in the summer. The insulation exceeds the Building Regulations fabric insulation values by about 40 per cent.
Its energy efficient features include triple glazed windows, which can be opened. Each window has a brise soleil sun shading system that breaks up the sun’s rays to reduce direct summer sunshine entering the building, with different sizes on each side of the building.
Lighting and transport
The design maximises natural light. There is a small heating system using air source heat recovery pumps connected to small radiators. Photovoltaic on the roof provide electricity and all the lighting is provided by energy efficient LED lamps.
Foleshill is clad with white render and wood effect Rockpanel boards on the ground floor. Rockpanel boards are durable, made of highly compressed stone wool fibres from basalt, a volcanic rock. Each panel is at least 50 per cent recycled material, with a 60 year life span, and will be recycled at the end of life.
The site is easily accessible by public transport. It also has an electric car charging point and bike storage.
It leads the way for carbon emissions reduction in this type of building, with significant projected annual carbon emissions savings (411 tonnes carbon dioxide a year).
The building has an Energy Performance Certificate A with a score of 12, very close to net zero.
Whole Life Cycle automatic energy and occupancy monitoring is being carried out for three years after construction. Results to date indicate energy use to be half of that predicted.
Pre-construction analysis prepared by AECOM, demonstrated a £450,000 (A$808,751) saving over a 40 year period, less than a third of the equivalent cost of a traditional building, and provides significant savings over its lifetime (a minimum of 6.3 per cent over 40 years).
Because of increased fuel costs, the additional cost of construction at Foleshill will be offset faster than predicted when compared to a conventional building.