Sustainable Home Design Series: The Old Forge with Baker Brown Architects
Balancing sustainable materials and reducing the energy demand during and post building construction will always be a difficult measure, especially with the rising cost of materials and of living. A key aspect to look out for is reusing materials locally, but where do you draw the line with being eco-conscious and compromising on quality and cost?
IGOLO has spoken with Tom, the associate director of Baker Brown Architects about their recent project - The Old Forge and how their methods and approaches to design create sustainable and resourceful Architecture.
Baker Brown are experienced eco-architects and circular economy consultants- designing beautiful buildings, places, and pieces of the city for a better future. They value practices such as sourcing locally, resource mapping, and using local skills and materials when designing: ethics we all should be considering for the future of sustainable architecture.
Read on to discover Tom’s experience in sustainable architecture, and how companies such as Baker Brown are approaching eco-design today.
Could you please introduce yourself and talk about why you became an architect - what inspired you to enter the industry?
I have been working here at Baker Brown since I finished my degree in 2007. I have wanted to be an architect since I was a child really, as I loved drawing and designing things and wanted to find a career that was drawing based. It was one of those things where I just decided at a very early age that it would be a nice thing to do, and kept on progressing towards it without looking back. I was always keen on art and science based subjects at school, so being an architect is a great balance between a technical discipline and artistic creativity that I naturally gravitate towards.
Why is sustainable architecture important to you?
During my degree the scale and environmental impact of the construction industry really became apparent to me, in a way that I had been relatively ignorant of until that point. My Architectural education taught me to love quality spaces and buildings, but also to be super conscious of the impact that building can have environmentally.
So my motive as an architect has been to strike the balance between creating beautiful spaces, places, and buildings, but in a way that has as minimal an impact on the planet as possible. Generally if there is a client with a brief and a budget, then the building will probably be built, so when we are appointed to work on that project our obligation (as I like to think of it at least!) is to try and deliver the project with the lowest environmental impact as possible.
What changes, if any, have you made to your own home to make it more sustainable?
After entering the world of work 15 years ago, I’m only just now in the fortunate position to be getting my foot on the housing ladder. We finally got our mortgage last year for a rather run-down ex-council property on the outskirts of Brighton. The only sustainable thing about our house is that nothing has been replaced for about 40 years, so at least it has had a relatively low embodied energy demand in recent decades!
We’re currently planning light touch (hopefully high impact!) thermal upgrades to the house and considering saving toward a PV array, since the house is at the top of a hill with an excellent south-west facing roof pitch.
The Old Forge project appears to be primarily an extension build- was any demolition involved, and if so was there any reuse of the materials? How was it sustainably designed?
We tried to demolish as little as possible. A very small, quite ramshackle garden room had originally been on the back of the house and this was the only element demolished to facilitate the extension. The rubble from demolition was kept on site and used for the sub-base to the ground floor slab. Some internal finishes had to be removed to facilitate thermal upgrades, but we tried to keep this to a minimum. Excavation soil was used on the farmland adjacent to our site to keep this as local as possible too.
The project has two major elements of work: the refurbishment of the main barn-form house, where we thermally upgraded the walls, roof, and floors, and overclad the ends of the barn with a locally sourced timber rainscreen; and then the extension, which was a super-insulated timber frame structure with matching locally sourced timber cladding.
We also installed a new air-source heat pump. We did receive planning for solar panels, but these were left out of the project as a last minute cost-saving exercise to finalise the contract sum. We did however future-proof the extension so that these could be easily installed in the future.
Where did you source your materials for this project? Do you have any go-to suppliers that you trust, or do you choose suppliers project by project? What do you look out for when selecting sustainable materials?
The cladding was specified as locally grown sweet-chestnut, which is a fast growing coppiced timber and available just a short distance from the site. It has a similar durability and appearance to oak. We also used a local reclamation yard to match the roof tiles and masonry elements of the project.
Insulation materials varied on this project from timber fibre products to PIR, depending on the considerations of the space, breathability, and target performance. As much of the project was heavily constrained, sometimes we had to choose insulation with a higher embodied energy to reduce the overall energy demand of the building: this is always a difficult balancing act.
We typically choose suppliers on a project-by-project basis, and we usually undertake a resource mapping exercise in the early stages of a project to work out what materials and material expertise are available in close proximity to the project.
Lot's of glazing to draw warmth from the sun during the winter months and a large overhang to provide solar shading during the summer. Photography by Ivan Jones
Your Old Forge project utilises a lot of glass which certainly gives it a very open feel, but how did you go about minimising the risk of overheating that comes with glass?
The extension at the Old Forge was designed with an over-sailing gable end that provides not only a sheltered external space, but also solar shading to the glazed south-west corner. The ambition was to ensure that the thermal mass of the exposed floor screed would benefit from passive solar gain in the winter, but also to avoid any potential for overheating in the summer. Feedback from the clients after a year of occupation shows that this has worked well.
How do you go about balancing an energy efficient build, while also using sustainable and affordable materials for construction?
This is also quite a tricky balancing act. We generally try to create a building with low energy demands and construct with materials that have a low embodied carbon. But practicalities and costs do play a big part in this.
Normally we try to specify materials that are as close to cost neutral as ‘normal’ materials, and where these might be more expensive, explain the value of lower embodied energy and lower energy in-use to the clients. With the way that energy prices are rising and fossil fuel supply security is falling, many clients approach us with an ambition of reducing energy demand just on the basis of sound long term economics. In recent years, the cost of materials with a high embodied carbon have increased due to the rising cost of petrochemicals, whereas natural materials have reduced in cost due to increasing demand for alternatives. So this balancing act does seem to become easier over time. It seems things are moving in the right direction, just quite slowly!
We also try to look outside of conventional material streams where possible. We recently worked on a project where we were able to save ash trees felled from site due to ash dieback, and we used this to make high value, finish-grade structural elements of the house. So we effectively got a material source for free in a period of time where timber supply costs have been rising rapidly. Sometimes thinking a little bit outside of the box can help to reduce overall costs.
A new extension stretches out into a walled garden to accommodate a light-filled, open plan kitchen and dining room. Photography by Ivan Jones
Do you have any advice for new architects, designers, or even homeowners on how to renovate and design more sustainably?
Focus on fabric first principles before everything else. Reducing the energy in demand of buildings at the same time as reducing the embodied energy, and looking at making the most of passive ventilation and beneficial solar gain. Only after those avenues have been thoroughly explored should you consider how renewable technologies can enhance the scheme.
One of the big considerations in terms of minimising embodied energy is making sure you maximise the value of anything already onsite. We are often approached with an idea to demolish a building and replace it with a new one, when often the best first move would be to make the most of the embodied energy of the material and structures already there: this could be through careful deconstruction and salvaging; or by simply not demolishing at all, or at least minimising the material to be removed from the site.
Reducing the embodied energy of a building should also be a lifetime consideration. What are the maintenance requirements of the building? Can the building be useful or flexible beyond its current planned use? Can material be easily de-constructable or demountable for use elsewhere in the future? These are all important in terms of whole life carbon considerations.
It’s important to make the most of the context of the project. What materials are available locally? What low value materials can be used in high value ways? What local experts are there who can help you to turn these low value materials into high value items? We typically audit these things on all projects looking for ways that we might be able to make the very most of the site and the embodied energy of anything on site.