The BREEAM ‘Outstanding’ building for developer FORE reuses the frame of a 1970s building previously slated for demolition
The 7,400m² Windmill Green development in Manchester mixes retail, co-working and multi-tenanted workspaces over seven floors and sits on the fringes of the city’s historic centre, adjacent to the old Manchester Central station and the Midland Hotel.
The building is tp bennett’s first completed architectural commission in the city by its newly established Manchester office, won in an invited competition against Sheppard Robson, Leach Rhodes Walker and Fairhursts. The competition was run by FORE who was seeking proposals for the retrofit of the original five-storey 1970s office building, which had sat vacant for over seven years.
This followed a long history of attempts to regenerate the site since Stephenson Bell Architects produced a masterplan in 2006. These included a series of proposals for a tall office building of up to 33 storeys by Sheppard Robson, and a subsequent 17-storey office scheme designed by Eric Parry, which received planning in 2014 but stalled due to lack of funding.
FORE, however, acquired the site at the end of 2015, having assessed the previous proposal against the option of keeping the existing 1970s frame, doing a deep retrofit and adding two to three storeys – with the retrofit option economically and sustainably offering a better result at about a third of the cost of the new build.
The building, which has been reclad in green terracotta tiles alternating with glazing, consists of co-working spaces on the ground and first floors, alongside a double-height reception area with a 7m-high living wall. Extensive shower and cycling facilities have earned the scheme a Platinum Cycling Score accreditation.
A further four storeys of highly flexible office space are topped by a 218m² communal roof terrace (the largest in Manchester), with a 108m² indoor roof pavilion with a kitchen providing free coffee. 600m² of planted sedum roof sits alongside this, with a series of apiaries to support biodiversity.
The building has its own fleet of scooters, made by a local business, which are free for tenants to use, as well as Brompton cycles for hire. Bifacial solar panels have been fitted which absorb light from the underside as well as the top, boosting efficiencies by up to 20 per cent and generating additional electricity through reflective light.
This is a really strategic regeneration site in Manchester, so it was important to design a building that interprets the local character in a modern way and creates a diverse commercial community, with sustainability at its heart.
The new mass of the building and the extended floors ties the form with the surrounding urban grain. The façade identifies with Manchester’s rich heritage of the use of terracotta in many notable Victorian buildings, including the adjacent listed Midland Hotel and St George’s House. The sculptural and plastic quality of the clay gives great character to the city’s architecture. The rhythm and detail of the new façade borrows from this local material. For example, the first-floor balcony mirrors the conference centre and animates the corner. The green hue of the terracotta glaze reflects the traditional Victorian glazed tile.
Sustainability was key driver in this scheme; it is a flexible space with A3 use, co-working and traditional office space. tp bennett reused the existing frame and foundations, and added new efficient façade system and services in order to regulate internal environmental conditions.
Underfloor displacement ventilation with exposed soffits has been used so the building capitalises on its existing thermal mass to regulate temperature variations. Efficient LED lighting systems and onsite PV generation also increases the efficiency and sustainability of the site. To influence wellness and biodiversity the building has green roofs, apiaries and a living wall in the reception.
Yvette Hanson, principal director, tp bennett
We are always looking for opportunities to refurbish and transform obsolete buildings into beautifully designed spaces that are sympathetic to their context and inclusive of their communities, and Windmill Green is a great example of how we work. The project has transformed a derelict and vacant building on a strategically important site in the centre of Manchester into an ultra-sustainable and high-spec workspace that encourages creativity, collaboration and a sense of community.
The site had been subject to a number of proposals for redevelopment with a series of new-build towers proposed – and when we purchased it a planning permission for a 17-storey tower was in place. However, having reviewed the permitted scheme, we concluded that a better result could be achieved by keeping the existing frame and doing a deep retrofit to create a more sustainable building and a workspace that would provide Manchester with something it was missing.
Ultimately, we believe we can do well by doing right and that a broad, holistic approach to sustainability can in fact drive higher financial returns. We bring together a deep commitment to carbon reduction to deliver buildings that not only better reflect the way people live, work and interact today, but also drive profitability for investors and tenants – while at the same time fostering a positive social impact.
Basil Demeroutis, managing partner, FORE Partnership
Start on site October 2016
Completion March 2019
Gross internal floor area 9,260m²
Form of contract Design & Build
Construction cost £14.2 million
Construction cost per m² £1,533
Architect tp bennett
Client FORE Partnership
Structural engineer Curtins
M&E consultant Crooks Walker Consulting
QS Walker Sime
Landscape consultant Scotscape Smartscape
Acoustic consultant Lighthouse Acoustics
CDM coordinator Gardiner & Theobald
Approved building inspector Building Consents
Main contractor Kier Group plc
CAD software used Revit, AutoCad
Environmental performance data
Percentage of floor area with daylight factor >2% 100 per cent
On-site energy generation 8.1kW (Sunpreme Bifacial solar panels with 24 per cent efficiency – enough to power all lighting)
Airtightness at 50pa 3m³/h.m²
Heating and hot water load 14.4kWh/m²/yr
Overall area-weighted U-value 0.48W/m²k
Lighting load -4W/m² at 450 lux
Design life 20-30 years
Embodied/whole-life carbon 183kgCO2/m²