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Eco-refurb on 1930′s Home: Case Study by Lucy Pedler

Posted on April 19th, 2010

Our architectural practice, archipeleco, had been designing eco-refurbishment projects for our residential clients for five years when we decided to up sticks and move from London to Bristol. One of the reasons for moving was to be able to carry out an extreme eco-refurbishment on a 1930’s house we had just bought in central Bristol and see how much we could reduce our carbon emissions and general environmental impact as a family. We had proposed some of the more substantial eco-refurbishment measures for our clients but often they did not end up being realised due to various constraints (time, money, planning restrictions) and we wanted to test out these ideas ourselves.

 

Our house is a larger-than-typical detached property built in 1934 and lived in for many years by an elderly couple who loved their garden but did not do much to keep their house up to standard - an ideal property for two architects to use as a laboratory for some of our more challenging ideas. We also wanted to collect as much data for the house once it had been finished to inform the eco-refurbishment debate. We were lucky enough to have the help of Dr. Paul Benson from De Montfort University who helped collate the data and format it into digestible documents.

 

The house had 225mm thick solid brick walls, a timber roof and leaky metal single glazed windows and when we bought it, there was not a millimetre of insulation to be seen anywhere. 18 months later and the house has a lovely warm tea cosy of insulation (80mm polyisocyanurate) on all the walls, a double layer of insulation in the roof (we converted the loft into our architectural office so our commute was down to a minimum), floor insulation (with recycled newspaper material) and new double glazed low E-coated windows. As a result, our house uses about a third of the gas for heating consumed by the same size house (accounting for the fact that we also work in the house all day).

 

We use compact fluorescent or LED lights (plus a few conventional bulbs) and this, combined with occupant habits, has resulted in the use of electricity being one quarter of a house of the same size. It should also be said that 1930’s houses are often designed to let lots of natural daylight in and ours is particularly light, meaning that we don’t need to rely on artificial lighting a lot of the time.

 

We also wanted to see if we could reduce the use of new, high environmental impact materials and to this end have used the existing floor boards on the first floor and reclaimed timber for the floorboards of the ground floor. Sourced by Bioregional Reclaimed, these boards used to be joists in an old house and were reclaimed, planed down and made into beautiful tongue and groove flooring. We used linoleum and slate where we needed a smooth washable surface and there are no fitted carpets in the house to ensure a healthy interior environment. The old plastic gutters and downpipes were replaced with aluminium rainwater goods and we built a deck on the back of our house with reclaimed decking and green oak timbers.

 

We wanted to reduce our water use to a minimum – although we will not run out of water on the planet, it still has a carbon load in that each time we flush water down the drain, it takes energy to clean it and pump it back into our houses. We have showers with low flow heads, dual flush/low flush WC’s, water butts in the garden and again, occupant habits (even with two teenage girls!) means that our daily water consumption is 71 litres (the average water consumption in the UK per person is 150 litres per day).

 

And last but definitely not least, we have been growing our own vegetables. This has been a mixed success – having lived in London most of my life, the most I had ever done was growing tomatoes in my back yard but when we moved to Bristol we had the opportunity of digging up some of the flower beds and making a productive garden out of them. After planting several sets of seeds at the wrong time and in inappropriate locations, I went on an organic gardening course and this year have high hopes of providing at least some of our vegetable needs this summer. We also have a veggie box from local company Better Foods which fills in the quite large gaps in our food production.

 

All in all, the project has been a fantastic learning experience for us as practicing architects and although I drive my family mad with all the geeky graphs and monitoring data I collect, they would all agree that the house is a very comfortable place to live. We give tours of the house through Old Home Super Homes– the next one is 11th September and bookings can be made through the OHSH website www.sustainable-energyacademy.org.uk

 

In addition to running our architectural practice, I am director of The Green Register, a not for profit organisation that provides training in sustainable building practices throughout the UK. We are running a series of seminars on eco-refurbishment for both professionals and homeowners in 2010. The next seminar for construction professionals is in Bristol on 13th May (see www.greenregister.org.uk for more details) and a new one day course for homeowners will be held in Bristol in September (date TBC).

 

 

 

 

Eco-renovation features to 29 Redland Hill, Bristol

 

1.            External Works:

·         Existing compost

·         Gardening/recycling garden ‘waste’

·         Fence posts & doors

·         Willow fences

·         Porous paving

·         Existing herb garden

·         New vegetable garden

·         Heat treated timber cladding

·         Green oak canopy over deck

·         Reclaimed timber decking

·         Aluminium rainwater goods

 

2.            External Envelope:

1.  
   • Airtightness test
   • New high performance timber windows
   • Cellulose insulation under flooring
   • 2x insulation in roof with breather membrane
   • 80mm external wall insulation and render
   • Draft proofing front door

 

3.            Heating/hot water:

·         Gas condensing boiler

·         Solar panels

·         Passive solar/conservatory

 

4.            Lighting:

·         Use of natural light

·         LED/compact fluorescent lighting

 

5.            Interior finishes:

·         Natural & clay paints

·         Reuse of existing floorboards on 1^st floor

·         Reuse of existing 1930’s interior doors

·         Reclaimed flooring on ground floor with natural oil finish

·         Slate, sea grass, linoleum

 

6.            Water:

·         Dual flush WC’s

·         Low flow shower

·         Water butts outside

 

7.            Waste:

·         Bristol Wood recycling project

·         Firewood

·         Garden waste

·         Skips

·         Yard sale

·         Cardboard packaging

 

 

 

7. Technical data available:

 

• Architects drawings – existing and proposed
• Construction details of external envelope (walls, floor and roof) – before and after
• Photos (before and after)
• U-values (before and after)

 

 

8. Data collected after occupation:

 

• Airtightness test
• Thermographic imaging
• 12 months of bills (water, gas and electricity)
• 12 months temperature logging with graphs illustrating the outcomes
• 12 months solar thermal panel output
• Energy Performance Certificate
• SAP rating
• NHER rating

 

9. Other post occupancy information:

 

• Food growing
• Waste reduction
• Transport

 

10. Lifestyle

• No tumble dryer
• Open fire
• Veggie box

 

 

Tags: case study, Eco-refurbishment
Posted in Case Studies |