Workshop: Zero carbon schools

Zero carbon schools

 

A workshop to explore the technological feasibility and commercial viability

University of Reading

-          21 January 2009 –

 

Attendance:  35 persons as per list

 

Background

The Government’s renewable energy strategy includes an ambition for all new school buildings from 2016 onwards to be zero carbon.  This will involve a major step change in design from existing school buildings most of which date back to the late ‘50s and early ‘60s when a low environmental footprint was not part of the design brief.   For many secondary schools in Reading such as Reading Girls School, Prospect and Kendrick, rebuilding rather than refurbishing is the only viable solution for stock about 50 years old

 

This one day workshop considered our current state of knowledge and what has been achieved   in three recent low energy buildings in Reading namely the Students Services building (SSB) at UoR,  Special Needs school at Meadway (SNS) and the 6th form provision at Reading Girls School (RGS) and an outline study for rebuilding the general teaching block (GTB) at Reading Girls School.  It then proceeded to consider what steps remained to achieve zero carbon.

 

Goals

MM outlined the desire of Reading Borough Council (RBC) to take a progressive approach towards reaching zero carbon. A large amount of work would be required in a short period of time if approval was given for an early draw down of funds from the primary capital programme.  Any future buildings should reflect the importance that RBC attached towards reaching the zero carbon goal in a cost effective manner.

 

SSB, UoR

KL described the design approach for this 2300 m2 student services building.  Design features included –

 

Very well insulated box

Large windows to capture day light

Top/bottom openings to encourage natural ventilation

Underfloor heating to maximise use of available space

Open floor planning where possible

Ground coupled heat pump (GCHP) with no back up boiler

 

LM described the design features of the GC heat pump system

 

25 boreholes, 100m deep

Pipes coupled together through header located near surface

2 90 kW Geothermal International heat pumps capable of providing space heating or cooling

Compact plant room

Uncluttered roof

 

A visit was made to the building when the outside temperature was +2C yet the heating was off because the internal gains were offsetting the heat loss through the fabric.  The system had performed very well for 15 months with only one of the heat pumps required at any one time to provide heating. The other could therefore be used to provide cooing when required for the two presentation rooms.

 

SNS, Meadway

AJ described the design brief and the architectural solutions for this special needs school of 12000 m2 which had in a period of 3 months increased the number of pupils from 47 to 93.  These included -

 

Arc of classrooms south facing

Large windows with controlled openings front and back

Sloping roof

Acoustic damping materials on all reflective surfaces

Controlled shading to limit sunlight

Maximise use of day lighting

Big open spaces for communal activities all on single floor with no step

All spaces under one roof

Minimise loss of curriculum time due to movement

Controlled environment with actuator mounted roof vents

 

DP described the provision of the services and the use of renewable energy sources –

 

Two 90 kW GCHP supplied by Geothermal International to supply space heating and cooling when required

Top up boiler condensing gas 65 kW

Renewable electricity from roof mounted wind turbines and photovoltaic arrays (PV)

Hot water ring main supplied by top up boiler

Small CHP plant to provide hot water for thermal pool 

 

Initial experiences had been very good and building was meeting expectations.

 

6th form provision, RGS

SW described the design brief for this building which was on a small site squeezed between existing buildings and Northumbria Avenue so orientation was fixed.  This included –

 

Minimise use of energy

Enhance natural ventilation

Maximise use of day light

Large windows low E

Lighting controlled by sensors

Renewable electricity PV arrays orientated south to maximise light capture

Low maintenance

 

Building still under construction with occupation due in autumn.

 

GTB, RGS

RM outlined the design concept for a general teaching block of 18 classrooms, single storey, south facing  linked by north facing corridor.  Design features copied those of SSB and SNS in that –

 

Sloping roof,

high ceiling following roof line

large windows with openings top and bottom south facing

smaller clestory windows to north

passive shading to minimise summer gain including use of deciduous trees

maximise use of day lighting with light pipes to fill back of class room

use only natural ventilation

underfloor heating

 

 

Renewable energy would be provided by a combination -

 

Water coupled heat pumps backed by an artificial lake

PV array mounted directly on pitched roof which could be extended as costs decreased

100 kW wind turbines 

 

Zero carbon could be achieved by exporting renewable heating and electricity to the surrounding houses when not required by school and importing when school could not meet its requirements.

 

Steps to zero carbon

Following a discussion in smaller groups,  the following were agreed –

 

·                     monitoring renewable energy production and consumption in the 3 buildings discussed at workshop

·                     deciding whether how energy usage could be further minimised

·                     monitor reliability and availability of GCHP to determine need for any back up boiler

·                      

·                     investigate advantages and disadvantages of south facing classrooms

·                     optimise balance between insulation level and internal heat gains

·                     optimise ways of building RES into building fabric

·                      

·                     develop criteria for psychological well being in classrooms

·                     develop ways of monitoring carbon account of school

·                     collecting and reusing rain water

·                     sufficient time to think design through

 

Way forward

There was a lot of work that needed to be done quickly to get to zero carbon buildings.

It required close collaboration between architects, service providers, renewable energy suppliers and researchers like at the School for Construction Management and Engineering at UoR.

 

It was worth considering setting up a zero carbon network to maintain contact and share experiences and use the opportunity of any new BSF funding to take the next steps to zero carbon.  A method for funding the zero carbon research should be sought.

 

Rayner Mayer

SVRF, SCME

UoR

 

Participants
 
Myles Milner            Reading Borough Council
Charles Ainslie         Reading Girls School
 
Kieran Lilly               Stride Treyhan
Brian Lacey             Halcrowyolles
Alan Johnson           Hunters and partners
Neil Champion         Pope Consulting
Derrick Pope
Simon Waite            Hampshire Architects Department 
Neil Boardman 
Paul Chandler 
Lee Marshall            Geothermal International
 
Frank Mills               SKM
Paul Wale
 
Colin Barwick           FMD, University of Reading (UoR)
Nigel Hodgson          
 
Hazim Awbi             SCME, UoR             
Derek Clemence Croombe
Geoff Cook
Jennifer Whyte
Mohammed Alshitawi
 
Pam Lewis               SCME/SCP
Rosario Nobile
Rayner Mayer
Christina Bristow
 
John Oversby           IOE, UoR
Kendra Gittus           BUD, UoR                               
Nigel Hartley            
 

Apologies

Patrick Bateman     National Energy Foundation

Howard Hughes      Oxfordshire County Architects

Richard Gooden      Hampshire County Architects

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