Ullet Road Eco Office Project The eco retrofit of a 1950s doctor’s surgery into low -carbon commercial and residential accommodation www.ullet-eco.co.uk
• The Building Built in 1950, with consulting rooms downstairs and family accommodation upstairs • Located in a late Victorian and Edwardian area heavily bombed in the May 1941 blitz • Solid wall property with metal lead light windows and pebble dash façade with brick and tile features • Cavity wall extension added in the early 1980s as other doctors joined the practice • Latterly used by the Primary Care Trust and then a children’s charity exclusively as offices and family rooms • Complex architecture - a mixture of duo-pitch, mono-pitch and flat roofs – not ideal for retrofit! • In need of remedial work to cure damp, replace blown steel lintels and repair pebbledash and windows • Lowest possible EPC rating on energy efficiency
• Building Objectives Reduce net energy demand as near as possible to the Passivhaus standard of 15kwh/m 2 /year, by a combination of – Insulation (walls, floors and roofs) – Window replacement – Air-tightness measures • Maximise the generation of renewable energy • Renovate a building in need of repair • Extend building space by: – Erection of a new garden office (commercial) – Loft conversion (residential) • Be true to its original style and features, but enhance with new artwork and design • Use recycled and ‘natural’ materials as far as possible • Provide a healthy and convivial working and living environment for its occupants • Promote low-carbon building development, using UK and especially Merseyside firms and products where at all possible
• Commercial and Provide 6 individual ground floor offices with common meeting, reception and Social Objectives kitchen areas • Be suitable for the disabled, and for people cycling, running or walking to work, having – Shower and changing facilities – Bike shed – Disabled WC – Electric vehicle charging points – Shared electric car for trips out for supplies and appointments during the day (if tenants require) – Good location by Smithdown Road shops, bars and cafes, bus routes and Sefton and Greenbank parks • Suits local and especially green entrepreneurs who would benefit from working with compatible businesses • Provide a self-contained flat with separate services, ground floor entrance and accommodation over first and second floors
How we’re eco • Significant generation of renewable energy • Replacement of gas by electricity for office heating • Ready for the smart grid – smart vehicle charge units and maximum use of off-peak electricity for heating and cooling • High levels of insulation and air-tightness to minimise heating and cooling requirements • Controlled ventilation • Reduction in street noise by different glass thicknesses in triple glaze windows • Use of natural paints, plasters and floor coverings – no volatile organic compounds • Reduction of journey to work carbon emissions - support for those walking, running or cycling to work by providing showers and changing facilities, together with the daytime use of a shared electric car • Significant planted area – green roof, grass covered parking area, fruit trees trained up perimeter walls • Recycled bricks and other building materials
• Renewable Energy 3.75kwp solar PV for use in the offices, using an Sanyo HIT array mounted over newly constructed garden office – estimated 3,125kwh electricity/year • 2.3kwp solar PV for use in the flat, using Solar Century C21e tiles embedded in south facing tile roof – estimated 2,000kwh elec/year • 2m 2 Thermomax HP400 evacuated tubes on east facing roof for office hot water – est. 1,368kwh/year • 2m 2 Thermomax HP400 evacuated tubes on west facing roof for flat’s hot water – est. 1,368kwh/year • Daikin Altherma reversible Air Source Heat Pump to provide winter heat and summer cooling to offices, using under floor pipe- work, together with contribution to winter hot water. Planned to use mostly off-peak electricity. Impossible to estimate kwh until building’s thermal performance has been measured over time.
• Broxton Street – a 1880s end-terrace house in Project Influences Wavertree retrofitted in 2010 to very low carbon by the registered social landlord, Plus Dane, using Broxton government funding from the ‘Retrofit for the Street Future’ programme. • internal insulation • high levels of air-tightness • solar thermal • Mechanical Ventilation and Heat Recovery (MVHR) • Geoff Morgan from Rodney Environmental Consultants, a member of the Eco Office team, monitors its performance remotely • A number of useful lessons in the performance of super- insulated buildings have been incorporated into the Ullet Denby Road design. Dale • Denby Dale – the UK’s first accredited cavity wall Passivhaus, a new-build completed in 2010 by the Green Building Store building company. They produced an excellent DVD and also assisted us at a training day in their Huddersfield base. • The Transition Towns movement and earlier sustainable community initiatives and writers (Fritz Schumacher, Paul Goodman etc).
Energy saving • External Wall Insulation (the tea cosy), (Retrofit) rendered with brick and tile slips to retain existing appearance – u-values range from 0.12 to 0.15 • Ultra thin floor insulation - 25mm vacuum The EWI tea cosy insulation product, is equivalent to 200mm EPS – u-value around 0.15. • Roofboards (modified resin insulation) on pitched and flat roofs – 100mm between rafters and 110mm above - u-value around 0.10 • Visible from front - thermally broken aluminium window frames, housing triple glazed units in which the leaded lights are encapsulated – u-value around 1.4 • Not visible from front - triple glaze uPVC windows – u-value around 1.1 • Air-tightness membranes, tapes and grommets at all junctions and service entrances • Use of wet plaster on walls • Careful detailing of window and door apertures • LED lighting throughout offices (around 15% more efficient than low energy fluorescents)
Energy saving (New Build) • Load bearing 175mm Structured Insulation Panels (SIPs), with additional 30mm of EPS insulation to support render – u-value around 0.13 • 180mm EPS floor insulation – u-value around 0.18 • Triple glazed uPVC windows and doors – u-value 1.1 (including frame) • Air-tightness tapes around doors and windows, and where SIP panels are joined • Air-tightness grommets around cable entries • Controlled ventilation through trickle vents above windows • Additional summer ventilation through thermostatically controlled extractor fan and opening windows • Heating through off-peak storage heater, topped up in very cold weather with small daytime convector heater
Heating, Cooling & • Heating – it shouldn’t need a lot! • Overheating may be more of a problem. Ventilation • Office heating using an Air Source Heat Pump (ASHP) and a single zone warm water under floor heating (UFH) system, principally operated at night under an off-peak electricity tariff, but with an option to switch on manually if occupants get cold. • Warm water buffer cylinder will retain some of the heat generated at night, for use in the day if the temperature drops. • Air Source Heat Pumps work best when the difference between the air temperature and the desired output temperature is low. They’re not Heat Pump especially good for hot water supply where you need temperatures of 55-60 o C to kill the legionella bacteria. So we’re doing three things: • Maximising the input air temperature by enclosing the unit in a lean to greenhouse • Supplementing hot water heating with an office solar thermal system and an immersion heater • Keeping the UFH water temperature low – flow around 45 o C with a 5 o C drop on return • The system will work in reverse in the summer, transferring heat from the building to the outside, like a fridge, again mostly running at night but with a manual option when required. • Solar thermal for the flat hot water supply, supplemented by a small gas combi boiler with radiators. Solar Thermal • After considering the space that would have been required by a suitable mechanical ventilation and heat recovery (MVHR) unit and its ducting, it Distributed was decided to use constant volume extractors instead, supplemented trickle by opening vents within the existing chimney stacks in the summer to ventilation & provide ‘passive stack effect’ cooling. passive stack.
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